500mm and Nikon D850, mounted on Arca-Swiss foot The first thing that strikes you looking at the Nikkor 500 PF is its size, or lack thereof. It seems like Nikon is defying physics in being able to make this long of a lens this small. This lens is smaller than my Sigma 70-200 f/2.8 Sport, and weighs considerably less. How did Nikon manage this? The answer lies in the “PF” designation, for its phase-fresnel optics. It’s not exactly new science, since lighthouses have used PF optics for more than a hundred years. This technology lets lenses be really thin, and glass weighs a lot. The 500 PF weighs 1460 grams (3.2 pounds) and is only 237mm (9.3 inches) long. Lots of gadget bags and backpacks could easily hold a lens of this size, in contrast to its’ 500mm f/4 lens cousins. The barrel is magnesium-alloy, yet the lens is still light. For such a small size, Nikon crammed in 19 elements in 11 groups. The aperture has 9 blades. It uses 95mm front-mounted filters (no drop-in filters). Speaking of 500mm f/4 lenses, the Nikkor 500mm f/4 costs about US $10,300 while this costs $3,600. That extra f-stop will cost you dearly, which also includes your spine. The f/4 weighs 3090 grams (or 6 pounds, 13 ounces), which is more than double the weight of this f/5.6 lens. Camera sensors used to be poor enough that low ISO meant the difference between quality and garbage. Nowadays, though, higher ISO is usually not a problem. This means that f/4 lenses are much less of a necessity than they used to be. Camera auto-focus systems are also much better than they used to be, so slower lenses can now be used in conditions that used to only be f/4 territory. Both Nikon and Canon have realized this fact, and they’re starting to produce lenses that reflect this new reality. Beware that this is an “E” lens, so many lower-end and old Nikons won’t be able to control the lens aperture. The electronic aperture is supposed to be a little more accurate and also capable of shooting at higher frames per second. The D2 and D200 or older cameras won’t work with E lenses, for instance. This lens appears to be well-built and is weather-sealed, but those are quite murky terms. Nikon won’t refund your money if the lens gets water damage, and I haven’t disassembled the lens to see how well built its innards are, either. This same caution goes for the other lens manufacturers, and not just Nikon. The front lens element does have a fluorine-based coating, which I know from experience with my Sigma lenses is really good at minimizing dirt, fingerprints, and smudges. Lens Controls Lens control switches The 500 PF comes with just about all of the bells and whistles of Nikon’s “exotics”. The A/M switch lets you manually override focus, and is a bit less sensitive than the M/A autofocus override mode. The M position will stop all autofocus behavior. The FULL switch maintains the full 3-meters-to-infinity focus range, while the other position limits the near focus to 8 meters. The focus on this lens is so fast that focus-limiting isn’t really needed in many situations. The VR switch offers both Normal and Sport modes. The Sport mode is ‘smoother’, in that it doesn’t re-center the optics after a VR stop/start, so the subject doesn’t do a jump in the viewfinder. Sport mode offers about 4 stops of stabilization (1/30s), which I would get about 1/3 of the time. For moving subjects, this is the mode you’ll want. The Normal mode will cause an image jump with a VR stop/start, but it’s much more efficient at stabilizing. I could get over half of my shots sharp at 1/15s, and when leaning against a wall I could occasionally even get shots down to 1/4s, which is about 7 stops! This mode is what you want for stationary subjects. The Memory Recall switch works along with the MEMORY SET button on the opposite side of the lens barrel, near the lens mount. It will save the present focus position and you can then have any of the 4 focus buttons near the front of the lens focus to that distance whenever they’re pressed. You’ll also get a beep, if the bottom-most switch is in its forward “note” position. If you slide the switch to the AF-L position, it will activate the focus-lock when any of the 4 focus buttons near the lens front get pressed. If you use the AF-ON switch position, the 4 front buttons will focus just like the camera AF-ON button. Accessories Plastic HB-84 bayonet lens hood included Lens case is quite nice, easy open, and padded The lens case includes a shoulder strap and a belt loop as well. Visual Comparison Size comparison: Sigma 150-600mm versus Nikkor 500mm The Sigma 150-600 C lens was zoomed to 500mm, to compare it to the Nikkor 500mm. The Nikkor only weighs 75% as much as this Sigma lens. General Impressions A minor gripe I have with all my Nikon lenses is NO Arca-Swiss mount on the tripod foot. The shot at the top of this article shows the lens with a separate Arca-Swiss plate that I mounted to the foot. Just about nobody mounts lenses like this on a tripod, monopod, or gimbal with just a tripod screw. Nikon still hasn’t caught on to this. Vignetting is pretty much a don’t-care at any aperture; it’s easy to rid in a photo editor, if desired. I didn’t notice any distortion, nor did I expect any. There wasn’t any coma that I saw in any of my shots. I also didn’t notice any focus noise. And speaking of focus, it focuses accurately at all distances and apertures after I calibrated it on a target that was about 50 feet away. I have rarely noticed a bit of extra flare when point it at a subject backlit by bright lights, but I tend to avoid this type of scene in my photography anyway. Phase fresnel is more sensitive to this kind of lighting than regular optics. Problems of this sort are overblown; it’s rarely an issue, and typically a very minor effect. I did all of my testing using the Nikon D850. Lesser cameras may show worse resolution and focus speed measurements. I did use an IR-converted Nikon D7000 when testing infrared performance. I did throw in a shot using my D500, too. Focus Speed I measured the focus speed by setting the lens at f/5.6 and minimum focus distance (about 3m, or 10 feet). I then timed how long it took to focus on infinity (using phase-detect of course) under sunny conditions. I measured 0.308 seconds. I used “slow-mo” video at 120 fps to review the focusing action (looking at the focus scale). It would, of course, be crazy to be typically switching focus from 3 meters to infinity. In normal shooting, focus is extremely fast. It’s my understanding that the lens elements responsible for focus are lightweight, and can be shifted very fast. I found the focus accuracy and repeatability to be excellent in good light. I wouldn’t recommend using this lens for sports or birds in flight when light levels get low. Although it’s not really intended for use in poor light, this lens focuses well down to about EV 5. Subject contrast makes a big difference in how well it will focus without needing to ‘hunt’, and I found that it would start focus-hunting at about EV 4. Teleconverter I tried using Sigma’s TC-1401 1.4X teleconverter (700mm and f/8.0). I did this, because both Nikon and Sigma tell you to not do this. I wanted to mention that you have to put the teleconverter onto the lens before you mount it on the camera, or else autofocus won’t work. I also need to mention that only the “f8” focus points will work, which is fairly limiting. Stick with the center point to avoid surprises. I actually think this combination works pretty well. Autofocus and VR both work, as well as metering. Focus speed is decent in good light, but I don’t recommend this combination in poor light for moving targets. My D850 and D500 are supposed to have the same autofocus capabilities, but I’d swear that the D500 is better at focusing this combination in poor light. I’ll be working on a separate article on this topic, but suffice it to say that the lens resolution is better than you might think. Focus calibration is required, of course. I have read that the Nikkor 1.4X teleconverter causes the same low-light issues that I have observed with the Sigma. Note that the EXIF data in the photos doesn’t register the actual f-stop and new focal length, because it can’t ‘see’ the Sigma teleconverter. Also, you can’t save a separate entry for focus calibration with the teleconverter. I always save a little note taped onto the inside of the lens cap that has the focus fine-tune values for both with and without the teleconverter. This may be a “don’t care” on mirrorless cameras. 500mm and Sigma 1.4X TC on D500 f/8 Infrared I used my Nikon D7000, which was converted to 590nm infrared by Kolari Vision. The camera sensor also has their infrared anti-reflection coating on it. The results are very, very good. I don’t see any problems using the lens at this infrared wavelength. Nikkor 500mm PF at f/5.6 with 590nm infrared Lens Resolution This lens resolution “signature” looks very unique, probably due to the phase-fresnel lens design. It’s the only lens that I have measured that looks best wide-open. With a lens that doesn’t go any wider than f/5.6, that’s extremely good news; there’s no reason to stop it down, unless you want deeper depth of focus. Incredibly, the resolution is nearly as good on the frame edges as it is in the central portion of the frame. As always, I am only reviewing a single lens copy. Note that shots focused on infinity are limited by air turbulence. Don’t think that the lens isn’t sharp at long distance. Horizon shots are the worst. I use the MTFMapper program to perform resolution and focus tests, which you can get here: https://sourceforge.net/projects/mtfmapper/ My resolution chart size is 40” X 56”. Big charts provide a more realistic working distance; the actual target distance is included in each plot below (nearly 17 meters). All of my resolution tests are done using unsharpened, raw-format from my Nikon D850 (45.7 MP). I use live view and contrast-detect focus, to eliminate any concerns about focus calibration. I’m showing the best results from about 10 shots at each focal length and aperture tested. I halted each resolution test after stopping down to f/16, because the diffraction effects ruin the resolution beyond this aperture. Even f/16 starts the resolution plunge, but sometimes you need the depth of field. The lens stops down to f/32, if you really need it. The contrast plots are real contrast plots, and not the theoretical ones that lens manufacturers put out. They include the camera sensor effects, since you’re going to be using the lens with a real sensor. MTF50 lp/mm resolution, f/5.6 Peak resolution, central = 58.5 lp/mm Peak resolution, edge = 52.5 lp/mm Peak resolution, corner = 49.6 lp/mm MTF Contrast plot, f/5.6 Now that shows how little astigmatism these optics have. Lateral chromatic aberration, f/5.6 MTF50 lp/mm resolution, f/8.0 Peak resolution, central = 54.3 lp/mm Peak resolution, edge = 47.7 lp/mm Peak resolution, corner = 47.8 lp/mm MTF Contrast plot, f/8.0 MTF50 lp/mm resolution, f/11.0 Peak resolution, central = 47.1 lp/mm Peak resolution, edge = 45.9 lp/mm Peak resolution, corner = 42.7 lp/mm MTF Contrast plot, f/11.0 MTF50 lp/mm resolution, f/16.0 Peak resolution, central = 40.3 lp/mm Peak resolution, edge = 38.9 lp/mm Peak resolution, corner = 37.3 lp/mm MTF Contrast plot, f/16.0 Summary This is rapidly turning into my favorite lens. I rarely bother with a monopod/gimbal or tripod, since it weighs so little. The VR-Normal works so well at slow shutter speeds, that hand-holding is realistic even in very low light. This lens has enough resolution that you can do significant cropping, if needed. Ironically, more cropping is done on long-lens shots than any other type. Sample Pictures 500mm 1/1000s f/5.6 ISO 640, cropped “distance” shot The crater detail is amazing. I shot it high in the sky to minimize turbulence. Looks like a telescope shot Minimum focus distance, 1/2000 f/5.6 Pixel-level detail from the shot above. Enough said. Bokeh sample, 1/2000 f/5.6 ISO 500 He just wanted his picture taken; I didn’t argue. 1/640 f/5.6 I had to throw in a bird-in-flight shot 1/2500s f/5.6 ISO 800

I had a brief period of grief when Adobe abandoned standalone versions of Photoshop. I’m a huge fan of using raw-format images, and every new camera model’s raw format is different. I was convinced that any of my new camera’s raw photos wouldn’t be supported in my Photoshop CS4. Some people (like me) naively believed Adobe when they bought a “lifetime” license for Photoshop. I guess Adobe didn’t specify how long a lifetime was. It turns out that there is a way to keep Photoshop CS4 updated, however. It’s a bit complicated, but it works. What I’m about to describe is a pure Windows discussion; I don’t know how to do the same thing using a Mac. The key to using raw-format photos (e.g. Nikon’s NEF or Canon CR2, CR3) in Photoshop is to first convert them into the Adobe “generic” DNG format. DNG stands for “digital negative”, and it’s still a raw format, just a different raw format. Many other photo editors understand this DNG format, as well. Fortunately, you don’t lose any quality by converting your raw photos into the DNG format. To be clear, though, you’ll be using the DNG file and not your camera’s original raw-format file to make use of Photoshop. There’s another problem to solve, however: how to set up the Adobe Camera Raw plug-in to be able to use DNG photos in Photoshop CS4. Convert Raw Shots into DNG Format The DNG format continues to be supported by Adobe. They still offer their “DNG Converter” program, and it’s free. Here’s a link to their Windows/MacOs converter program: https://helpx.adobe.com/camera-raw/using/adobe-dng-converter.html The Adobe DNG converter program is very fast, and it lets you batch-convert your raw files as well. In this way, it takes very little labor or time to convert your shots. Some programs only support older DNG formats, so the DNG Converter program lets you convert your camera raw photos into a specific DNG version. Adobe Photoshop CS4 can only use DNG files up to version 5.7. Convert into a specific version of DNG for older programs After installing the Adobe DNG converter, you can execute it in Windows by running it from the Programs list. The most common way to use the DNG converter is to just click on the “Select Folder…” button that lets you tell it where your raw (e.g. .NEF, .CR2, etc.) files are. This button is located in the “Select the images to convert” section. Next, click the “Select Folder…” in the “Select location to save converted images” section. This assumes you also select the “Save in New Location” option; you can also save the new DNG files in the same folder as your raw shots, if you wish. If you need the DNG version number to be compatible with older programs, then click the “Change Preferences” button to pick another version. For Photoshop CS4, the latest DNG format that can be selected in the converter is version 5.4, as shown above. Finally, just click the “Convert” button to start converting your camera’s raw files into the DNG format files. Your original raw files won’t get modified, so they’re safe. Install the Last Supported Camera Raw Plug-in Version 5.7 Adobe stopped supporting the Camera Raw plug-in for CS4 after version 5.7, so that’s what you need to get for Photoshop CS4. There are actually two different plug-ins for Windows; the 32-bit and 64-bit versions. Each of these plug-ins is called “CameraRaw.8bi”, and the 64-bit version will be found in a directory called “win64”. It’s confusing to have these two versions called the same name, so be careful to keep them in separate locations. Here’s the link to get the Camera Raw V5.7 plug-in : http://download.adobe.com/pub/adobe/photoshop/cameraraw/win/5.x/Camera_Raw_5_7.zip The discussion about getting this file (NOT the "updater" version) is found here: https://community.adobe.com/t5/camera-raw-discussions/how-to-upgrade-to-camera-raw-5-7/td-p/12060996 If you already have an older version of Camera Raw, then you should be able to update it using the “Help | Updates” option. If that won’t work for you, then you can get plug-in installed manually. I’m going to describe how to manually install the plug-in in Windows. First, you need to un-zip the “Camera_Raw_5_7.zip”. Make sure you exit Photoshop. Execute the CameraProfiles.exe in the un-zipped, newly-created folder “Camera_Raw_5_7”. Follow the program’s instructions. Using Windows File Explorer, navigate to the 64-bit folder called: C:\Program Files\Common Files\Adobe\Plug-Ins\CS4\File Formats If the folder shown above doesn’t exist on your computer, then create it manually. Windows will probably ask you for permission to do this operation. If there is a file in this directory called “Camera Raw.8bi”, then you should move it to some other folder for safekeeping. This is an older version of the 64-bit Camera Raw plug-in. Copy the newly-created file in your un-zipped folder “Camera_Raw_5_7\win64\Camera Raw.8bi” into the 64-bit folder “File Formats” shown in the path above. This is the new 64-bit plug-in. For the 32-bit plug-in, you’ll need to navigate to (or create it): C:\Program Files (x86)\Common Files\Adobe\Plug-Ins\CS4\File Formats If there is a file in this directory called “Camera Raw.8bi”, then you should move it to some other folder for safekeeping. This is an older version of the 32-bit Camera Raw plug-in. Copy the newly-created file in your un-zipped folder “Camera_Raw_5_7\ Camera Raw.8bi” into the 32-bit folder “File Formats” shown in the path above. This is the new 32-bit plug-in. Summary Now, you should be able to use your camera’s raw files (converted into the DNG-version-5.4) in Photoshop CS4 via the Camera Raw plug-in. If you open the DNG file in Photoshop, it will automatically execute the Camera Raw plug-in to open the photo. You now have a technique that should allow you to use your new-model cameras’ raw shots, once you convert them into DNG, in your standalone Photoshop CS4! Make your investment in Photoshop pay off for a little bit longer with this trick. Using Camera Raw from Photoshop CS4

You assume that it doesn’t matter which copy of a new lens you buy. When a reputable lens manufacturer makes a particular lens model, you’d think that they’re all about the same, right? Think again. I have read that you should only worry about lens quality variation when you buy the cheap consumer models. My own experiences say, to borrow from the French, “au contraire, mon frere”. I used to have two copies of the FX Nikkor 85mm f/1.4 AF-S. This is not a cheap lens, and is considered premium “pro” gear. One lens copy was about 25% lower resolution than the other; I ended up selling the soft lens copy (at a 50% loss!). 18-140 Nikkor at 140mm I presently have two copies of the Nikkor 18-140mm AF-S DX f/3.5-5.6 G ED VR lens. It’s not a professional lens by any means, but it has pretty good sharpness, decent focus speed, small, light, and is very versatile with its large zoom range. I thought it would be an interesting exercise to compare several properties of this lens model. When a lens manufacturer puts together a complicated lens like this, it’s impossible to assemble the parts identically from one lens to the next. Tiny parts tolerances along with small assembly variations can have a bigger impact on the final optical characteristics than you might imagine. I used the free MTFMapper program and a 4-foot-by-five-foot mounted test chart to get the measurements that follow. This is the same program that NASA used to evaluate the lenses on the Mars Perseverance Rover. Nikkor 18-140mm: 17 elements in 12 groups. Courtesy Nikon Resolution Pretty much everybody understands that lens copies may differ slightly in resolution, so I’m going to start the lens comparison with that parameter. A proper lens resolution analysis needs to show you the whole lens results, and not just a measurement from the lens center or from an edge. To better understand optical characteristics, you also need resolution information in both the sagittal (think wheel spokes) and meridional (circle tangent) directions. I used a 24MP DX camera for all of the measurements that follow. Vibration reduction was turned off, and the camera was mounted on a sturdy tripod. The mirror was flipped up, to minimize any vibrations. The resolution measurements were made using the same resolution chart at the same distance with the same aperture, and the same lighting for both lenses. If measurements are taken at a different camera-to-subject distance or aperture, the resolution will change. I used a linear translation stage to carefully shift the camera/lens between each resolution test shot by 1 millimeter, and then picked the sharpest one. Even contrast-detect focus isn’t quite accurate enough to nail the focus, and slightly missed focus really impacts resolution. Lens ‘A’ MTF50 resolution: 18mm f/3.5 Lens ‘B’ MTF50 resolution: 18mm f/3.5 Notice that lens ‘A’ above has a slightly lower peak resolution (63.1 lp/mm) versus than lens ‘B’ (65.3 lp/mm). This sort of difference cannot be seen in photos, and it takes a computer analysis to note this small of a difference. The peak resolution for lens ‘A’ is pretty much in the optical center. For lens ‘B’, you’ll notice that peak resolution is below the center. The lens B was probably assembled slightly off-center. Also note that the general shape of the meridional-direction resolution is nearly a perfect circle. The sagittal-direction shape is very different, yet quite similar between the two lens copies. The drastic drop-off in resolution away from the center is the price you pay for a super-zoom lens. A landscape photographer wouldn’t be very pleased with the quality of the photos along the edges, at least not with the lens aperture wide-open. The lens edge resolution is improved by stopping down, but it never approaches fixed-focal length lenses or pro lenses. Lens ‘A’ MTF50 resolution: 140mm f/5.6 Lens ‘B’ MTF50 resolution: 140mm f/5.6 At the longest zoom setting of 140mm, lens ‘A’ is clearly better, having a peak MTF50 resolution of 50.2 lp/mm, while lens ‘B’ only reaches 40.7 lp/mm. Notice how similar the meridional and sagittal plot shapes are between the two lenses. They may not be identical twins, but they’re clearly siblings. On most lenses, the meridional resolution is worse than the sagittal. This is expected from the design of the lens. If I had to choose which lens to keep, it would be lens ‘A’, at least based upon resolution. The lens ‘B’ is about 19% lower in peak resolution. MTF50 Contrast The contrast plots are what most photographers are familiar with. In case you didn’t know, though, nearly all lens manufacturers only publish ‘theoretical’ values, and not actual measured values. Also note that theoretical plots don’t even consider the camera sensor; my MTF50 contrast plots include the camera sensor effects. My contrast plots additionally include measurements at 50 lp/mm, and not just 10 and 30. 18mm f/3.5 and 140mm f/5.6 MTF 10,30 : Courtesy Nikon Note that in Nikon’s theoretical MTF contrast plots above, they expect the meridional-direction (M) results to be quite a bit worse than the sagittal-direction (S) results. Lens ‘A’ 18mm f/3.5 MTF 10,30,50 Contrast Plot Lens ‘B’ 18mm f/3.5 MTF 10,30,50 Contrast Plot Lens ‘A’ 140mm f/5.6 MTF 10,30,50 Contrast Plot Lens ‘B’ 140mm f/5.6 MTF 10,30,50 Contrast Plot The contrast plots show that lens ‘A’ is clearly superior. The ‘B’ lens has a wider spread in measured readings, indicating that its lens elements aren’t as carefully aligned as they are in lens ‘A’. Lateral Chromatic Aberration Nearly every photo editor can correct for lateral chromatic aberration, so this lens defect isn’t as important as resolution and contrast. 18mm f/3.5 lens ‘A’ lateral chromatic aberration 18mm f/3.5 lens ‘B’ lateral chromatic aberration 140mm f/5.6 lens ‘A’ lateral chromatic aberration 140mm f/5.6 lens ‘B’ lateral chromatic aberration You can’t tell much of a difference between these lenses in regards to lateral chromatic aberration. The values are a bit larger than most lenses, but that’s another price you pay for a super-zoom lens. Fortunately, photo editors can mostly eliminate it. Summary Identical lenses are a fantasy. If manufacturers could make lenses that were imperceptibly different from one to the next, they would probably have to cost tens of thousands of dollars. Generally speaking, about the best you can do is to focus-calibrate your lens to your camera, assuming that your camera supports that feature. Mirrorless cameras are of course better at getting accurate focus, but lens manufacturing variations are still going to bite you. It would be interesting to know what “meets factory specifications” actually means. I think that the manufacturer is just hoping that you don’t look too closely at what you’re buying. Don’t get me wrong. I still use these lenses quite a bit. It’s a lot better to get the shot than get nothing, and lenses as portable and versatile as these encourage you to bring along your ‘real’ camera and not just depend on your cell phone camera.

There’s more science and history that goes into camera lens coatings than you could imagine. Without the invention of anti-reflection lens coatings, modern lenses couldn’t exist. With nothing added to the surface of a glass lens, about 4% of the light hitting it gets reflected back and is lost. A camera lens with only a single element has two air-glass surfaces, so the reflection losses double. Modern lenses often have upwards of 20 elements in them, so un-coated surfaces would result in huge light losses. Much of the light that gets reflected off of lens surfaces will bounce around inside the lens and end up fogging your image with horrible flare. In 1935, the Ukranian physicist Alexander Smakula of the Zeiss company invented the world’s first anti-reflection coating. This invention was so important that it became a German military secret. The Allies only discovered this secret in early World War II, and so lens anti-reflection coating knowledge quickly spread worldwide. You may have heard of Zeiss T* optics. The “T” is short for “transparency”, and alludes to the anti-reflection coatings used in their lenses to yield superior optical transparency. Light reflecting off of a coated lens Notice above that there are a pair of reflections shown. A bush in the upper reflection looks green, while the same bush reflection looks yellow as the light bounces off of a different lens surface with a different coating on it. Somehow, the lens is reflecting different colors of light off of different lens element surfaces. Read further to get some insight into how a lens maker can cause this to happen. Typical camera lens design with several glass elements A typical camera lens with six elements is shown above. Each air-glass surface gives more opportunity for light to reflect back, instead of being transmitted through the whole lens. Picture courtesy of Wikipedia. Light wave reflecting off of a coated lens There’s a lot to explain in the picture shown above, so here goes. The Greek symbol “lambda” is λ. This symbol is commonly used to represent the wavelength of light. For camera lenses, the most important light wavelength to worry about is green (the same reason that there are twice as many green pixels in camera sensors as there are red or blue pixels). Green light wavelength is about 500 billionths of a meter. The letter η shown above represents the “index of refraction”. The index of refraction indicates how much power a substance has to bend light. The η₀ above represents the index of refraction of air, while η₁ is the index of refraction of the lens coating, and ηₛ is the index of refraction of the lens glass itself. Light actually slows down when traveling through a substance with a high index of refraction (it only moves “at the speed of light” while in a vacuum, whose index of refraction value is 1.0). The R₁ above is the light wave that gets reflected off of the lens coating. The R₂ above is the light wave that is reflected off of the lens glass element surface. These reflected light waves are drawn in orange. The coating material is shown in darker blue, while the lens element glass is shown in light blue. The “T” above is the transmitted light wave that has survived the journey through the lens coating and the surface of the lens glass. The drawing above is slightly inaccurate, because the transmitted light wave is actually "bent" and exits the lens in a different direction than when it entered the lens. Notice that the lens coating thickness shown above is a quarter of the light wavelength (¼λ). This is no accident. The distance traveled by the reflected light wave R₂ is a half-wavelength farther than the light wave R₁ that reflects off of the lens coating. The extra half wavelength of travel happens because it goes a quarter wavelength through the coating, and then reflects back another quarter wavelength to exit the coating. When the pair of reflected light waves R₁ and R₂ combine, their wave crests and troughs now align. This alignment difference causes the waves to cancel each other and “disappear”, which is called “destructive interference” by physicists. Since the reflected light waves (the green ones, at least) cancel each other out, all of the incoming light energy gets transmitted through the glass lens element instead of having some (about 4%) being lost due to reflection! Incredibly, by forcing an extra reflection off of the lens, you end up not losing any light, and it all gets transmitted through the lens! This is the opposite of what your “common sense” would tell you would happen when forcing extra reflections. Now you can start to appreciate the genius of Alexander Smakula (he went on to teach and do research at MIT in the United States). The discussion above is only “theoretical”, however. The lens coating index of refraction η₁ should ideally be half of the value in between that of air η₀ and the lens glass ηₛ. The index of refraction of typical lens glass is about 1.5, while the index of refraction of air is 1.0003. The ideal lens coating index of refraction would then be about 1.25. Reality rears its ugly head, though. The substance “magnesium fluoride” has an index of refraction of 1.38. It is transparent and can be applied after heating in an oven (to form a vapor) and deposit a thin coating onto lenses. This coating thickness can be carefully controlled, so they can put down a quarter-wavelength- thick layer. Magnesium fluoride is tough enough to withstand the rigors of daily use and lens cleaning. This type of lens coating isn't the only substance used by lens manufacturers, but it's probably the most common. Imagine if you had to accurately apply 125 billionths of a meter of something onto glass. And people expect this to get done for cheap. Good luck. They haven’t yet found a substance that is closer to the ideal index of refraction of 1.25 that has the mechanical and optical properties needed for a lens coating. At least nobody is confessing to knowledge of this desirable substance. The net result is that they can make single-coated lenses that reduce reflections down to about 1%, versus the theoretical 0%. Light waves arrive with different colors (therefore different wavelengths). This means that the coating thickness optimized for green light isn’t very efficient in reducing these other reflections. Light waves also strike the lens at different angles, and therefore they don’t travel precisely one-half-wavelength farther to cause the perfect reflection-canceling behavior. So guess what? Lenses now get “multi-coating”. These multiple coating layers on lens surfaces cause yet more reflections. The outer coating layers (with slightly lower index of refraction values) can further reduce (via reflection destructive interference) light losses. If each layer of a coating on a lens surface is a different thickness, then it becomes possible to stop the losses of different colors of light. Just like the Germans before the War did, lens makers aren’t divulging their secrets of just exactly how they’re making lens multi-coatings that enable near-perfect light transmission. Thanks, Alexander.

I decided to do some detailed comparisons between Lightroom and Topaz DeNoise AI. The Lightroom product does a pretty good job at sharpening and getting rid of noise, but DeNoise AI is just a little better. I use DeNoise AI for a couple of reasons. Sure, I use it to tame noisy photos, but I mainly rely on it to sharpen details. The artifical intelligence built into the Topaz products is just superior to the conventional pixel-based image processing logic that is used by Lightroom. In the sample shots that follow, I always begin with raw-format files. This way, I’m not depending on the camera to “clean up” the image data in any way. I’m not a fan of using high ISO, because it destroys resolution and loses too much dynamic range. There are times, however, when you have to crank up ISO or else lose the shot. Topaz Severe Noise algorithm at work on ISO 25,600 shot The shot above shows the before-and-after results of processing a shot taken at ISO 25,600. I never willingly go this high in ISO unless I’m desperate. The resolution is largely destroyed, and the dynamic range takes a huge hit. If I want to totally rid luminance noise at super-high ISOs, then this is the algorithm that I use. I used the Nikon D850 to take this shot of oranges. Its sensor is still near state-of-the-art, but even this camera can’t make ISO 25,600 look acceptable to my eye. Lightroom at work I processed the same ISO 25,600 shot in Lightroom. The results are actually pretty similar to what Topaz did. The noise is gone, but fine details have been sacrificed to rid that noise. So far, I’d have to say that there isn’t a compelling reason to use the Topaz product instead of the Lightroom product. Topaz Clear algorithm at work If I process the same shot using the Topaz Clear algorithm, the fine details look better. A tiny amount of luminance noise is left behind, but the overall shot is sharper. I personally prefer this compromise over total elimination of the luminance grain. Much of my photography involves long focal lengths around 600mm and motion-stopping shutter speeds in the range of 1/2000 through 1/4000. This generally forces me to use ISOs up to 6400. My cameras are able to retain an acceptable amount of resolution and dynamic range at these ISOs, but only with careful post-processing. Before I discovered Topaz DeNoise AI, my upper ISO limit was 3200. I feel that its AI algorithms have allowed me to get about one more stop, or ISO 6400, before the shot quality drops too low for my taste. D500 with 600mm at f/8 1/4000s ISO 2,500 The shot above was shot with a Nikon D500, using an ISO of 2,500. This is much more typical of what kind of ISO is needed with long focal lengths. I’m showing a pixel-level view of a photo processed using Lightroom. The shot is a very distant pine tree that hasn’t been affected too much by atmospheric turbulence. At this viewing scale, the shot looks quite sharp, and you can still make out the pine needles, even though the tree was several hundred meters away. Same photo processed with Topaz Clear algorithm At the same pixel-level view, the Topaz-processed shot shown above looks about the same as the photo processed using Lightroom. Edge haloes seen in Lightroom processing If you look more carefully, however, there are edge haloes that can be seen in the Lightroom-processed shot. I drew arrows to show edges that demonstrate these haloes more clearly. The haloes aren’t gross, but they are definitely there. If you don’t sharpen as much in Lightroom, the haloes will decrease, but then the details start to turn into mush. There’s always a balance between sharpening enough without having the edge haloes become obvious. No edge haloes in Topaz processing If you look in the same locations as the shot processed in Topaz, the edge haloes are gone. Also, you see a few more pine needles that don’t seem to even exist in the Lightroom version. Somehow, the Topaz algorithms sharpen but don’t generate any edge haloes in the process. This seems to be the primary difference between Topaz and other photo editors that rely on conventional pixel-based enhancement logic. Summary Granted, the Topaz results aren’t a huge difference from Lightroom, but the subtle quality differences are definitely there. I have to mention that it will definitely add more time and effort to use Topaz in your editing workflow, but I think it’s worth it. Someday, all image editors will be forced to adopt artificial intelligence in their sharpening and noise elimination algorithms. Start saving up to buy the new computers that have the necessary processing power (e.g. GPU) to keep up.

I got a DSTE battery grip for my Nikon D7000, after my 8-year-old Vello BG-N4 grip finally died. Vello doesn’t make a grip for the D7000 anymore, although they still do for models as old as the D7100. I gambled and bought the DSTE MB-D11H grip. The Nikon battery grips are fairly expensive, and you can typically buy between 4 and 6 generic battery grips for the price of a single Nikon grip. I own Vello grips for several models of Nikons, and this is the second time that I have had a Vello grip fail. Considering the price, I’m way ahead of the game compared to buying Nikon grips. The Vello grips have the same functionality as the Nikon ones, and all of the controls are in the same place as they are on the Nikon grips, too. I have had this DSTE grip for a several months now, and its still working perfectly. I wanted to wait and give it a good workout before I was willing to comment on it. So far, I have no regrets. This gamble has paid off. I honestly cannot tell the difference between the Vello/DSTE grips in terms of look, feel, or function. The only design difference is that the DSTE grip includes an infrared remote control, which lets you shoot from up to 27 feet (8.2m) away, in ideal conditions. The buttons and dials feel fine on both company’s grips; they don’t seem like a non-Nikon part at all. There are DSTE battery grips offered for other cameras, such as Canon, as well. I don’t know all of the camera models that are supported, but it appears at the time of this writing that DSTE has grips for the Nikon D7100, D7200, D850, D3100-D3300, D600-D610, D750 and D5300. There are probably many, many more supported cameras than this list. DSTE battery grip mounted on Nikon D7000 In the shot above, you can see the grip with its sub-command dial and lockable shutter release on the left. The little red window on the grip is its infrared sensor for the remote release. The DSTE grip has the same styling and feel as the camera materials. It includes two different battery drawers (just like the Vello) to hold either an EN-EL15-series battery or 6 AA batteries. You can also hook up the EP-5B AC power adapter to it, if you wish. If you don’t have an extra battery, the grip controls all work just fine without a battery installed in it. You can also operate the camera with no battery installed in the camera, and just inside the grip instead. There is, of course, a ¼-20 tripod socket on the base of the grip for tripod use. It's located at the correct location for proper left-right balance, as well. The specifications state that it weighs 234 grams, or about 8 ounces. Many people are really hung up on weight. To me, this extra weight is pretty trivial. I sometimes wonder if some people only wear shorts because slacks are too heavy. To each his own, as they say. DSTE battery grip rear view In the shot above, you can see the multi-selector, the AE-L button (mine is reassigned to be an AF-ON button), and the Main command dial. DSTE and Vello grips comparison You can compare the DSTE and Vello grips above. Except for the DSTE infrared receiver window, you can’t tell them apart. If the Nikon grip was included in the shot, I’ll bet you couldn’t tell it apart from the other grips, either. Infrared remote control Infrapro infrared remote control As I mentioned above, this little remote control worked for shooting up to 27 feet from the camera. It operates basically the same as the official Nikon ML-L3 remote, except that the “Infrapro Remote” only controls the battery grip. The DSTE grip only has an infrared receiver on its front, so you can’t operate it from the rear of the camera. I should mention that you need to set the camera release mode to “Mup” to use the remote. In this mode, you press the remote button once to flip the camera mirror up, and then press the remote a second time to release the shutter. This is optimal for ridding any vibrations when shooting, so it makes sense to operate in this mode. I don’t know if other DSTE grips for other camera models operate in this same way for remote photography, but I suspect they do. The remote is pretty small, and will easily slip into a pocket when you're not using it. It's only a little bigger than the Nikon ML-L3 remote. I have used it for several months with its original battery, so it seems to be pretty efficient with power usage. Weather sealing Forget about it. Keep in mind that Nikon offers zero warranty protection against water damage, in case you have any illusions about their gear. Just buy another grip if you drown your first grip; you’ll still be money ahead. Summary I don’t know about long-term durability of the DSTE grip, just like I didn’t know about my Vello grips’ longevity, either. So far, I’m very happy with it and have no regrets. I’m a huge fan of battery grips, mainly because of their better ergonomics, the superior balance with bigger lenses, and not worrying about running out of battery power. It's also simpler and quicker to remove the battery from the grip than the camera body for charging. If you haven’t tried a battery grip before, you might just find that you never want to be without one again. Relative to the price of just about any other piece of camera gear, adding a grip like this is about as dirt-cheap as it gets.

I thought it would be interesting to see how much sharper Topaz DeNoise AI could make photos appear. I didn’t want to do any hand-waving on this subject, but instead show real measurements to evaluate it. Since DeNoise AI is able to process raw-format photos directly, I came up with the idea of having DeNoise AI save its sharpening results into another raw-format file. I’m using DeNoise AI version 3.4.2. My (unsharpened) input raw file is from a Nikon D500 (.NEF), and my output raw file is in DNG format. Both of these file formats can be used by the MTFMapper program, which I use to measure lens resolution from special resolution test charts. An added benefit to this scheme is that it provides a means to actually measure how sharpness changes as the Topaz AI sharpening algorithm input configurations change. This is then an ideal way to know when the input parameters to an AI algorithm are optimized. Lens resolution is evaluated by measuring how quickly a straight black edge changes into the pure white of its background. Photo sharpening is achieved by reducing the distance it takes to transition subject edges from light-to-dark or dark-to-light, as well. Normally, web sites that report on lens resolution measurements are using un-sharpened raw-format photos of test charts. Some sites take measurements directly from the lens itself, and bypass the camera sensor. In any case, lens resolution measurements should never be based upon sharpened chart photographs (e.g. jpeg). I’ll show you why this is true in a bit. I normally use the Topaz DeNoise AI algorithm called “Clear” for my shots with an ISO of 6400 or less. This algorithm works for all of the input camera file formats. I run this artificial intelligence algorithm in “Manual” mode, with input parameters of “Remove Noise”=Medium, “Enhance Sharpness”=Low, “Recover Original Detail”=26, and “Color Noise Reduction”=7. I used to let the algorithm run in “Auto” mode, but I was never pleased with the results. Topaz DeNoise AI sharpening, “Clear” algorithm The shot above shows how to convert an un-sharpened raw photo into another raw format (DNG) after applying sharpening and noise removal. The Topaz program has five different AI algorithms to select from, and also provides the option to manually configure the sharpening/noise algorithms. Topaz DeNoise AI sharpening, “RAW” algorithm Topaz now has a new algorithm called “RAW” that you can use if you give it a raw-format input file. It’s super-slow to run, but Topaz claims it produces superior results. This is my chance to check the validity of that claim. I am running it in “Auto”, where it chose to use “Remove Noise”=16, “Enhance Sharpness”=46, “Recover Original Detail”=0, and “Color Noise Reduction”=0. I decided to have a contest between my favorite AI recipe “Clear” and the new “RAW” algorithm. I could then compare these output result files (DNG format) to the resolution of the original raw-format NEF file. I selected a shot of a resolution test chart using my Sigma 150-600 lens at 300mm f/6.3. Again, this shot was made using my Nikon D500. The ISO was 400, so this is primarily a sharpening contest, versus a noise removal contest. Despite its name, Topaz DeNoise AI is as much a sharpening program as it is a noise-removal program. Un-sharpened D500 raw (NEF) resolution test The peak MTF50 resolution in the plot of the un-sharpened test chart shot above is around 57 lp/mm. This is a fairly decent resolution, but can it be improved? Let’s see… DNG raw file output from Topaz “Clear” algorithm Wow. The MTF50 resolution measurements more than doubled, up to around 130 lp/mm! Strictly speaking, Topaz Denoise AI can’t manufacture extra resolution out of thin air, but visually it means that photos certainly look much, much sharper. This is why I like my “Clear” algorithm so much, in addition to its ability to get rid of most of the noise from my shots. DNG raw file output from Topaz “RAW” algorithm Now we’re talking. The “RAW” algorithm really did a nice job. Again, I used it with the default “Auto” mode, where it decides how to sharpen and rid the noise on its own. The downside, however, is that the algorithm takes nearly 20 times longer to execute than the “Clear” algorithm. Getting MTF50 resolution numbers of approximately 150 lp/mm is just outrageous, though. Unsharpened raw (NEF) chart center detail The shot above shows some of the resolution chart (center) target edge measurements, which are near 57 lp/mm in some spots. This is typical of a “decent”, but not outstanding lens. Raw (DNG) chart center detail, “Clear” algorithm results The chart center resolution MTF50 numbers from the “Clear” algorithm shown above are pretty crazy. It doesn’t seem like anything could out-do results like these. Raw (DNG) chart center detail, “RAW” algorithm results Lo and behold, the “RAW” algorithm really does get details sharpened up to unbelievably high levels. I have never seen MTF50 numbers like these before. It may be “false detail”, but it looks really, really good. Just as the Topaz people said, the RAW algorithm gives superior results. Unsharpened raw (NEF) chart corner detail The unprocessed NEF file gives pretty ho-hum corner results. To be fair, though, MTF50 resolution above 30 lp/mm looks pretty darn good. Raw (DNG) chart corner detail, “Clear” algorithm results The “Clear” algorithm corners have jumped to values that go beyond what most lenses look like in their centers. Impressive. Raw (DNG) chart corner detail, “RAW” algorithm results Interestingly, the corner results from the “RAW” algorithm aren’t as good as the “Clear” algorithm. They’re still really good, but the “Clear” algorithm beats the “RAW” algorithm here. AI algorithms work in mysterious ways. Just when you think they have a clear pattern of operation, they’ll surprise you. The same goes for AI-controlled autos; sometimes they have crashed for unknown reasons. Raw unsharpened NEF file MTF contrast plot DNG MTF contrast plot from RAW algorithm The MTF contrast plots show a couple of interesting things. DeNoise AI certainly makes them look better, but the spread of results seems to get larger, too. Those AI algorithms don’t seem to treat every detail or edge in the same way. Some details are improved more than others are, although all details seem to get at least some improvement. Original NEF without sharpening “Clear” algorithm “RAW” algorithm I processed a very distant plane raw-format photo with both the “Clear” and the “RAW” algorithms. In the original un-sharpened photo, you can’t even perceive many fine details. Both of the processed shots bring out an amazing amount of these “invisible” details. To be honest, I can’t readily tell the difference between the “Clear” and the “RAW” algorithm results; they’re both simply excellent. It’s amazing to think that the same lens was involved in the three shots shown above. AI sharpening gets shot quality to a whole new level. Summary I think you can now see why web site reviewers should never use sharpened test chart photos to evaluate lens resolution. The resolution measurements can be wildly manipulated to make a crummy lens look good. I do think that resolution-measurement software can be especially useful to evaluate and fine-tune programs like Topaz DeNoise AI. Using a program like MTFMapper, you have the ability to know which AI algorithms work the best, and by how much. You can also fine-tune algorithm input parameters to optimize your results, assuming you’re patient enough to spend the time and energy to do so. Given the very large difference in processing time between the different AI algorithms, you’ll have to decide if squeezing out a tiny bit of extra sharpness is worth it to you. You should also compare these results to invoking DeNoise AI as a plug-in from your photo editor, which means you won’t have access to the “RAW” algorithm at all. I have avoided a discussion of photo noise reduction here, since I haven’t yet figured out a good way to “measure” it. It’s easy to note if a photo is less “sandy” looking or has fewer color speckles in it, but it’s a lot trickier to be able to say by “how much”. Also, too much noise reduction inevitably destroys resolution.

Topaz Labs has recently updated their DeNoise AI to version 3.4.2. The main changes include improved AI engine efficiency, improved raw support, GUI additions, and some bug fixes. I had tried their older DeNoise version 3.3.4 on my Nikon raw (.NEF) files for both the D500 and D850. Version 3.3.4 failed miserably with my Nvidia Quadro FX 880M GPU. The new 3.4.2 version thankfully works perfectly with this GPU. Other file formats have worked on all previous De Noise versions, but the NEF files didn’t. You’ll want to do the denoise step before any other raw processing. I do most of my edits using Lightroom, so I’m going to concentrate on that Topaz/LR combination here. The Topaz company explains that their AI algorithms will perform optimally using the original (raw) file information, rather than the already-processed files from editors such as Lightroom. Lightroom understands the DNG raw format, so that’s what you want to use. This combination of processing is superior to letting Lightroom edit the raw file first and then invoke the DeNoise AI plug-in to finish. Be prepared for huge DNG files, however. The D850 files in DNG format are about 262 MB! You might want to save this processing technique for your special photos, unless you have loads of storage space. It would be tempting to eventually delete the DNG files after editing and exporting the results into jpeg, but it might be pretty difficult to re-create all of your edits later on from the NEF/CR2/CR3/ARW original. You should skip any sharpening/noise removal using Lightroom, and just let Topaz work its magic instead. You just need to start with DeNoise AI and then finish with Lightroom, instead of starting with Lightroom and then finishing with DeNoise AI. If you start with Lightroom editing the raw file first and then call the DeNoise AI plug-in from within Lightroom (which is what I always used to do) the quality is still extremely good. This new sequence of starting with DeNoise AI first just gets slightly improved results, at the cost of creating a huge DNG file (and then importing it into Lightroom). ISO 4000 processing with DeNoise AI The shot above shows one of my favorite recipes for processing photos that are in the vicinity of ISO 4000. This photo was shot with my Nikon D500. I use the “Clear” algorithm, with “Remove Noise” = medium, “Enhance Sharpness” = Low, “Recover Original Detail” = 26, and “Color Noise Reduction” = 7. I was never happy with any other photo editors for noise removal and sharpening for photos with an ISO above 1600. I no longer hesitate to use up to ISO 6400 after adding De Noise AI to my work flow. In a pinch, I’ll sometimes go to ISO 10,000 but I’m not too wild about the results. It wouldn’t surprise me if future AI algorithms are able to adequately handle even these high-ISO shots. Process the raw shot and save as DNG Procedure (Windows 10) to start with a raw-format input file Go to the folder with NEF (or other raw format) files using Windows Explorer. Select (or multi-select) the NEF/CR2/CR3 raw file(s). Left-mouse-drag file(s) onto the Topaz De Noise AI desktop icon. This invokes Denoise AI as a stand-alone application, versus a plug-in. If you select more than a single shot to drag onto Denoise AI, then you’re doing batch processing of the raw shots. Alternatively, you can also start up Topaz DeNoise AI and simply mouse-drag your photos or folder onto the running Topaz program. The finished shot, after processing the DNG file in Lightroom Using ISO 4000 (and generally even ISO 6400) looks gorgeous when I process my shots with DeNoise AI. I used to cringe when I had to go up to ISO 3200 using Lightroom or Zoner or Photoshop or DarkTable by itself. Topaz has really changed my opinion of what’s possible with high ISO shots. Both noise and sharpness show huge improvements. By the way, the (Nikon D500, 21MP) shot above was cropped by about 50%. ISO 4000 never used to look this good You should still strive to keep ISO as low as is practical, in order to preserve the maximum dynamic range. With big lenses, however, you’re stuck with high shutter speeds and therefore higher ISO. DeNoise AI 3.3.4 was a disaster with my Nvidia GPU. You can see above the kind of results I was getting previously, when I tried to directly process my raw (.NEF) shots with DeNoise AI. I would get a bunch of random black squares. This is now totally repaired in the newer software releases 3.4.1 and 3.4.2. You will also find that the algorithms run a bit faster with this newer version. They’re still slow, compared to conventional noise removal and sharpening in a photo editor, but AI processing results in vastly superior end results. If your computer doesn’t have a GPU (graphics processing unit), then you probably shouldn’t use Topaz DeNoise AI. Its artificial intelligence algorithms need huge computing resources, which GPUs provide. I predict that eventually all of the photo editors will be forced to adopt AI algorithms, since non-AI techniques can’t even begin to compete with the quality that products like Topaz De Noise AI provide. I don’t get any money from Topaz; I just think that photographers need to be aware of just how good the latest version of this product is.

I started processing my raw-format shots from my infrared-converted camera in Zoner Photo Studio. My go-to editor is Lightroom, but it does a poor job in creating a proper white balance. Infrared photos have a strong red cast to them, and Lightroom just can’t handle them properly. To do the effects shown in this article, you’ll need an editor that supports swapping color channels directly, or through a plug-in. A handy tool to have when editing color infrared shots is a red/blue channel swap plug-in. This channel swap is how to get your sky to turn blue, instead of the ‘tobacco’ color of white-balanced color infrared. I found a free plug-in from Flaming Pear that works in Zoner Photo Studio to perform this channel swap. I got my old Nikon D7000 converted into infrared by Kolari Vision, although there a few companies that will do a conversion like this. I chose a 590nm infrared filter, which allows part of the visible spectrum to get used and therefore enables color infrared shooting. Camera conversions that use long-wave infrared, such as 850nm, are strictly for black and white photography. You can of course achieve these same effects by purchasing IR filters, instead of getting a camera converted to infrared. If you use filters instead, then get ready to take a tripod along. Typical infrared shot with a red/blue channel swap The photo above started out with a very strange sky color. The procedures that follow show you how to convert your infrared shots to get the classic blue sky effect. Bear in mind that infrared doesn’t contain anything that can be called “color”. Therefore, any color assignments that you might make are just as correct (or incorrect) as any other. People tend to prefer color shots that have a blue(ish) sky, however. Install the free plug-in to swap red/blue color channels Before trying any editing in Zoner Photo Studio, I installed a library of plug-ins from Flaming Pear. Here’s a link to get the free plug-in. The Flaming Pear plug-ins can of course do a lot more than just swap color channels; you should probably try out some of their fun effects that they offer. Download the compressed plug-ins into the desired folder. For Windows, the file is called “freebies-win-latest.zip”. Decompress this file. Open up Zoner Photo Studio Go to the “Editor” tab Click the “Effects” tab to add the plug-in folder Zoner doesn’t like 64-bit, so select the 32-bit freebies folder. Select the “Settings…” to add plug-ins Click the “Add…” button to browse to the plug-in folder Once the plug-ins are ready for use, you can start editing your raw-format infrared photos. You really, really should be shooting in raw format to get quality results. Color Processing Steps for a Blue Sky (Do these steps for the first image, to set up the Zoner defaults) Raw photo: use the eyedropper tool to select a neutral area You’ll probably see something like the shot above before you set a proper white balance. To successfully use the eyedropper tool to set a white balance, you photo should contain something neutral in it, like a rock or sidewalk. You only need to do this white-balance operation once, since you can save the result in Zoner to be applied to all subsequent shots. Finished result of using the eyedropper tool Open the raw photo in Zoner Photo Studio Go to the “RAW” tab Select the White Balance Eyedrop tool Pick a neutral area in the photo, such as a sidewalk or stone Click Settings | Set Current as Default Now, opening other photos in the RAW tab will automatically white-balance them, or at least get pretty close. If you want to process non-infrared shots later, then you’ll probably want to set up other defaults at that time. Adjust the image to suit your taste in the RAW tab. (Green plants should now look blue, and the sky is tobacco-colored) Click the “To the Editor” button in the bottom-right corner. You’ll probably want to turn the sky into a shade of blue, which will then turn the plants into shades of yellow/orange. This step is where the Flaming Pear “Swap Red/Blue” plug-in comes into play. Many people are happy leaving the plants with a blue color; color infrared doesn’t have any set rules. Click Effects | Plug-in Modules | Flaming Pear | Swap Red/Blue After the plug-in finishes, your sky should now be blue and plants typically look a shade of yellow. Neutral white balance, before the red/blue channel swap Red/Blue channels are now swapped You can now touch up the photo with the usual editing tools, and then save it in TIFF/JPEG format. If you don’t like the colors, you can also convert the shot into black and white. Convert your shot into black and white I really love the plug-in called Silver Efex Pro 2. It’s made by the Nik people, who are presently working for DXO. While editors such as Zoner Photo Studio have built-in features to turn shots into black and white, they’re quite primitive compared to Silver Efex. This plug-in is installed using the same techniques shown above for Flaming Pear. Shot converted into black and white with Silver Efex Pro 2 Once the plug-in is installed, do the following steps to convert shots into black and white: Start in the “Editor” Click: Effects| Plug-in Modules…| Nik Collection| Silver Efex Pro2 Select whichever effect you like the best. You can even fine-tune the effect, if you wish. I’m a huge fan of black and white, and infrared landscapes can look stunning in black and white. Actually, black and white infrared photos are probably more “correct” than the color photos shown earlier in this article. Summary There are several photo editors available that can perform the red/blue channel swap for handling color infrared. There are a lot fewer editors that have the necessary range to get a proper white balance for color infrared. I mostly use Lightroom and plug-ins for my photo editing, but here’s a case where it just falls to its knees. I stopped searching after I discovered that Zoner had all of the capabilities (including plug-in support) that infrared processing needs. I’m not getting any money from the Zoner people, but I thought some of you would be interested in knowing about useful tools for editing of infrared. I’ll also mention that I save my sharpening and noise removal for the Topaz Denoise AI plug-in. Once it’s configured properly, I have seen no equal to its capabilities.

Most Nikon DSLRS and mirrorless cameras have a feature called Image Overlay. This is a vastly underrated capability that can really spice up your photographs. You can think of it as a “double exposure” technique, but it’s more powerful than that simple description. Sample camera models that have this feature include D5000, D7000, D7100, D610, D500, D850. I use this feature to add a moon to landscape shots that are just begging for a little something extra in them. It’s particularly interesting to be able to add a telephoto moon to a wide-angle landscape, to create an ‘impossible’ combination. The fact that these shots are created entirely in-camera makes it that much more powerful. Most people don’t realize that the Image Overlay feature actually creates a RAW output result, with an image quality that goes way beyond simple jpeg format. You should be using RAW input images, also. It’s of course possible to use an image editor with ‘layers’ to accomplish something like this. This technique, though, will probably yield better quality and also give you the ability to re-shoot on the spot if you decide that you don’t like the alignment, for instance. I actually keep a little library of protected moon shots on my camera’s second card slot. I protect these shots (using the little “key” button) against accidentally erasing them. This way, I always have the ability to add a moon, for example, to a landscape. I keep a variety of moon shots that have different positions and magnifications in the night sky, to allow flexibility with composition. Note that you have to remember to not re-format this “library” memory card; even “protected” images will be lost if you do that. You might want to copy your ‘library card’ to a backup card for safe keeping. Aloe reaching for the moon The example shot above shows how I added a moon to the sky. This kind of shot would not have been possible with a single shot. The moon was photographed at a much longer focal length, not to mention that the moon is virtually never in the right spot at the right time for your shot. Image Overlay Procedures I demonstrate a typical editing session in the steps that follow. The camera menus allow you to try out different images and balance their exposures, as well. You can select the shots from either memory card slot. Go to the Retouch Menu to find Image overlay Press OK to locate your first image to use Select the desired first image, then press OK Select the second image to overlay onto the first image Adjust the brightness of the second shot In the example above, I increased the exposure of the second (moon) photo by 1.5X. I could see the final result in the Preview window, prior to saving the combined photo. Note that my first photo was selected from my XQD memory card, and my second photo was selected from the SD card slot. Press the OK button to overlay the shots Press OK to save the result or Back to adjust further The finished shot Saving Photos To Another Card Slot If you want to move shots to your second memory card “library”, the images below show those details. You should begin by marking each photo you want to move as “protected” by pressing the little “key” button. This step is simple insurance against accidentally erasing them, and it will also simplify photo selection. The operations to copy/save images are found in the Playback menu. The steps assume that you have already marked the shots to copy as “protected”. Select the Copy image(s) option Locate the shots to copy Choose the “Select protected images” option here To make things easy, there’s an option called “Selected protected images”. If you have already protected the shots that you want to copy, then this option will grab them all in one step. Now, you can save the selected images onto your other memory card. Now you can easily build up a library of "stock" image files (mine are mostly moons at different phases, magnifications, and positions). Summary Nikon engineers did a really quality job when they designed the Image Overlay feature. This capability lets you create multiple exposures that have maximum quality, and you can complete the whole process in-camera. I typically only use multiple exposures for things like combining fireworks or adding a moon to the sky. This feature, of course, doesn’t care what you decide to combine together. You can always copy some of your original raw shots back onto your memory card later, to add a moon (or something else) after the fact. It’s gratifying to see that Nikon has chosen to carry this feature over to so many camera models over the years. It’s a pity that more people don’t use it, or are even aware it exists. This is something that you can have a lot of fun with.

When I got my Nikon D7000 converted into infrared-only, I decided to use the Kolari Vision company. The main reason I chose this company was because of the specifications they gave in regards to their IR filter covering the camera sensor. Kolari Vision offers (at additional charge) to put an anti-reflection (AR) coating over the surfaces of their glass IR filter that they install in place of the normal (visible-light) camera sensor filter. I was a bit skeptical about this AR coating (it’s adjusted to infrared wavelengths), but I decided to add this option when they converted my camera. They also add materials that are supposed to make this sensor filter easier to clean, if debris gets on it (which it always does). My camera conversion was with their 590nm sensor filter, but they offer the anti-reflection coating option for all of their conversion wavelength options. I wanted to mention that I don’t get any money from Kolari Vision, so I have no stake in anybody buying something from them or not. I just have a deep interest in infrared photography. Kolari Vision claims that un-coated IR sensor glass filters will reflect 7% of the light, while their coated filters reduce this down to 0.4%. They further claim that this reflected light bounces off of the rear of the lens aperture blades, and is a primary contributor to the dreaded hotspot in the middle of your photos (with many lenses). Hotspots, if the lens produces them, always get worse as the lens aperture gets stopped down, and this is the reason why. You can read for yourself about their anti-reflection coating here: The Life Pixel company, which also does IR camera conversions, doesn’t put anti-reflection coatings on their IR filters over the camera sensor. They claim that they tested this technology, and found that it made light transmission worse and didn’t help reduce hotspots in any way. All modern lenses have multi-coating, and they vastly increase light transmission. It doesn’t make any sense to me when Life Pixel claims that the anti-reflection coating reduces light transmission. They doth protest too much, methinks. Sorry, Shakespeare. So who’s telling the truth here? I figured that some testing was in order. I can’t prove that the reflected light bounces off of the aperture blades, but I can at least look at the end result of using a coated sensor filter. For many years, I have done infrared photography by using IR filters on my lenses. I always figured that it got me exactly the same results as an infrared-converted camera, except that the light levels were reduced when using the filters (compared to an IR-converted camera). I have always known that my Nikkor 50mm f/1.8 AF-D lens got a bad hotspot after stopping it down while doing infrared photography. Because of this, I always avoided using it when shooting infrared. The shot below shows exactly what I’m talking about. 50mm f/1.8 at f/7.1, 30s, ISO 800, Neewer 850nm IR filter You can clearly see the hotspot in the middle of the shot above, even though the lens was only stopped down to f/7.1. The hotspot was clearly visible, no matter which IR filter I tried on this lens. The hotspot got breathtakingly bad at f/16. This shot uses my own attempt at a white balance preset, and the color wasn’t modified by any post-processing editor. I could use Lightroom and its “radial filter” to mask the hotspot, but this is definitely a second-rate, band-aid kind of fix. I decided to re-create this shot with the same lens at the same aperture, the same filter, and the same lighting conditions. While I was at it, I also decided to try a variety of other infrared filters. The main change here is that I’m now doing these tests on my Kolari Vision converted IR camera. The shot above was done with my Nikon D7100, which has not been converted to infrared. I have seen this same hotspot effect when trying my other cameras with infrared filters, including on my D7000 before I got it converted into infrared-only. My shots would look okay wide-open, but would get ruined after stopping down beyond f/5.6 or so. In the test shots that follow, I am using the factory-set white balance that Kolari Vision provides, without any further modification by me in an editor. In regular photography, I would do lots of post-processing to alter the colors, including improving the white balance. 50mm f/1.8 at f/7.1, 1/800s, ISO 800, Neewer 850nm IR filter The shot above was with my Kolari Vision 590nm conversion, but also using the same Neewer 850nm IR filter on the lens that resulted in the nasty hotspot with my D7100. Notice a few differences from the previous photo using the same Neewer IR filter. The exposure went from 30 seconds to 1/800 second (over 14 stops)! The big thing, however, is the total absence of a hotspot. Kolari Vision’s anti-reflection coating appears to have made a huge difference. Also note the loss of color, due to the double-filtering of the light through two visible-light-cutoff filters (590nm and 850nm). I need to mention that I use Live View with an LCD magnifying viewer to see and focus when I put an IR filter onto a lens. It’s only a minor inconvenience, as long as I’m not trying to follow action. This combination even works in bright sunlight. Hand-held shooting is still possible with this combination of an IR-converted camera and an IR lens filter, although I typically lose about 3 stops of light. I decided to try some other filter tests at the same lens aperture, to see if the hotspot might show up with filtration changes. Kolari Vision 590nm sensor filter conversion only. 50mm f/7.1. No hotspot! Zomei 850nm 50mm f/7.1 with Kolari-converted camera. The Zomei 850nm filter also causes total loss of color information, and is extremely similar to the Neewer 850nm filter. Hoya R72 50mm f/7.1 with Kolari-converted camera. As you can see, the various IR filters on my 50mm lens didn’t make the hotspot appear at f/7.1. Next, I decided to see if I could coax a hotspot to appear with this lens by stopping it down to f/16. I had no filter on the lens, and only adjusted the exposure by stopping down from the previous f/7.1. Kolari Vision 590nm only. 50mm f/16. Tiny hint of a hotspot. Most people wouldn’t even notice it, but at f/16 my 50mm lens shows just the barest trace of a hotspot in the middle of the shot above. This lens is now totally usable for infrared, at any aperture. Despite what Life Pixel claims, I consider that the hotspot issue is indeed repaired (at least with my lenses) at lens apertures down to about f/11. This may not be a total cure, but I think it’s a huge improvement. When stopping down further, the hotspots are weak enough to largely be ignored. I rarely use f/16 or narrower apertures in my photography anyway, since it ruins resolution due to diffraction. I suspect that I’d be seeing hotspots if I had the “standard” Kolari Vision 590nm conversion done, which doesn’t include the anti-reflection coating on the sensor filter. I guess I won’t ever find out, since I don’t intend to ever get a camera converted that doesn’t include the AR coating. It’s a cheap investment to make sure your lenses perform as well as possible with infrared photography. Kolari Vision 590nm only. Adjusted white balance. I fixed up the white balance in the shot above, using the tree trunk as neutral gray. Notice that there is a bit of a glow from the bushes on the right. This is known as the “Wood Effect”, which comes from infrared heavily reflecting off of the chlorophyll in the leaves. This isn’t a central hotspot, and is generally considered part of the charm of infrared photography. You’ll have to make up your own mind if you like it or hate it. Most camera lenses demonstrate some of level of “glare” when the shot includes a subject with this heavy infrared glow. The shot above is typical. My Sigma 14-24 f/2.8 Art lens, although awesome with visible light, shows an above-average level of this glare in infrared. With most subjects the glare is ignorable, but sometimes the shots get ruined because of it. Kolari Vision 590nm only. Red/Blue channel swap. The shot above shows the more conventional red/blue channel swap from the white-balanced version, using my photo editor. The leaves changed from blue to yellow/orange, and the sky looks a bit more normal. The 590nm IR conversion retains enough of the visible-light spectrum to enable nice colors. It’s easy enough to also convert the shot into black and white, which I end up doing at least half of the time. I was going to make up a database of my lenses to indicate which ones would work for infrared. After the Kolari Vision 590nm conversion, all of my lenses work with infrared! There are of course some qualifiers in saying “all” of the lenses work; lenses don’t work equally well under all lighting conditions. My Sigma 70-200 f/2.8 Sport, which I initially determined to be totally unsuitable for infrared (using IR filters on un-converted camera bodies), for instance, now works just fine with most subjects. Another bonus from getting a camera converted to infrared is that my lenses that don’t permit a filter on them can finally be used to shoot infrared. Rokinon 8mm fisheye, 590nm infrared, red/blue channel swap The Rokinon 8mm fisheye doesn’t allow a filter to be attached. It works great in infrared, at least with the AR coating option that Kolari Vision provides. The shot above was at f/11. The reason I used f/11 is because this is one of two lenses I have that cannot focus to infinity in infrared. Stopping down to f/11 gets the lens reasonably sharp at infinity. It doesn’t look quite as sharp as with visible light, but still looks pretty good. Tokina 11-16mm at 11mm, f/8. 590nm infrared. I used Silver Efex Pro 2 on the shot above, to convert it into black and white. The 590nm conversion can still provide a nice white-foliage look that people mostly associate with only long-wavelength infrared like 850nm. The distant atmospheric haze was totally eliminated. This Tokina lens isn’t regarded as good for IR, but it looks fine to me. The main problem with this lens, as with several others, is shooting into very bright IR light (or just outside the field of view). The lens elements show lots of reflections and veiling glare when pointed at bright infrared sources. In shots like the one above, you’d never suspect it has any problems shooting infrared. 590nm infrared with Nikkor 24-70 f/2.8 at 24mm, f/9. My Nikkor 24-70 f/2.8 AF-S VR also has a poor reputation for IR, even with the Kolari Vision website’s lens database (“bad after f5.6”). It, too, is mostly working fine for me, through about f/11. I have the same caution about shooting into lights, however: don’t do it. Some subjects (especially beyond f/8) will cause an overall central glow, although it’s not quite what you’d call a well-defined hotspot. I used Silver Efex Pro 2 on this shot, too. The Luminescentphoto web site specifically states that their 720nm infrared-converted Nikon Z6 (didn’t say which company converted it) with this Nikkor 24-70 f/2.8 VR: “Hotspots at all apertures”. They rate it “Poor”. The shot above doesn’t have a smidge of a hotspot, and it’s stopped down to f/9. Sigma 70-200 f/2.8 with 1.4X teleconverter, 280mm, 590nm IR The Sigma 70-200 f/2.8 Sport lens isn’t supposed to work with infrared. This lizard obviously didn’t know that fact. Shot at f/4 1/3200s ISO 200. The shot above even throws in the 1.4X Sigma teleconverter. It’s curious that this lizard looks almost exactly the same in both visible and infrared light; most subjects look quite different in infrared. My Sigma 150-600 Contemporary lens works surprisingly well. I would have thought that all of the glass in that lens would have made it terrible at infrared. Maybe the Kolari Vision AR coatings are working their miracles there, too. 590nm, Sigma 14-24 f/2.8 ART, 1/640s f/6.3 14mm ISO 100 I couldn’t find any positive reviews regarding my Sigma 14-24 f/2.8 ART in regards to infrared. If you keep it pointed away from lights, it can produce fine IR images. It’s ironic that my cheap Nikkor 18-55 DX VR f/3.5-5.6 G II lens is excellent with infrared. It has better contrast and glare resistance than most of my other lenses do with infrared. It’s a slow lens, but I virtually never need a fast lens for infrared work (I don’t shoot it at night or even at dusk). It’s a pity that it doesn’t go wider than 18mm, though. Summary I have to admit that an IR-converted camera produces superior results, compared to using the screw-on IR filters over lenses instead. Many of my lenses that were previously unusable for infrared now work just fine in most (not all) circumstances. My super-wide lenses that don’t even have filter threads on them are suddenly my go-to lenses for infrared, such as my Rokinon 8mm fisheye. You might have noticed that just about all of the photos in this article were made with lenses that have been reported as either substandard or unusable for infrared. This was done intentionally. I have to question if anybody making those reports has tried to use an AR coated sensor filter. Again, you will want to avoid shooting into bright lights. Given this limitation, many “unusable” lenses are suddenly usable. Hand-holding shots instead of multi-minute, tripod-anchored exposures is a real treat. I can always use my 10-stop neutral density filter (most lenses) when I want long exposures. I think that the Kolari Vision anti-reflection coating on their infrared sensor cover filter makes a huge difference. The cost increase for this camera conversion optional feature is about the same as buying a single good infrared filter. Money well spent, if you like infrared shooting half as much as me.

Have you ever heard of focus-trap shooting? That’s where you set up your camera to wait until a subject moves into a pre-set zone of sharp focus. As the subject enters that zone, the camera automatically starts shooting. It stops shooting after the subject leaves the focus zone. If the subject re-enters the zone, the camera will start shooting once again. Humming bird fly-by: caught in a focus trap Focus-trap is useful for things like the finish line of races, where the photographer isn’t allowed to be there. He sets up his camera to automatically shoot the end of the race with his camera unattended. This feature is also used beside a trail where shy or dangerous wild animals will wander by, and you have your camera in a secured box with a hole in it for the lens to see through. It’s also great for shy bugs moving onto a pre-focused spot over a flower or waiting for birds to land on a perch. It’s not very straight-forward how you can do focus-trap with the Nikon D500 or D850, but it’s possible to do. High speed hummer: not easy to react to. For the shot above, I set up a focus position in mid-air where I knew that a humming bird would fly past on its way to eat. It’s almost impossible to shoot a humming bird up close if it’s not hovering or perching. With a focus trap, the camera could easily do what I find exceedingly difficult to do: get a shot in flight from just a few feet away. How to set up the camera Pre-focus your lens to the distance where you want your camera to trigger shooting. Set your shutter release to AF-C mode, and make sure you’re in auto-focus mode. Set Ch for high-speed continuous shooting to get lots of shots while the subject is in focus. This won’t work in manual-focus mode. You might want to set your focus-point selection to ‘single’, if you want a very selective focus zone, but this isn’t mandatory. Autofocus menu AF-C shooting priority configuration Focus priority with AF-C: only shoot an in-focus subject AF activation menu Select AF-ON only. Don’t allow combined shutter and focus Disable the Out-of-focus shutter release Go to the ‘Custom Settings’ (pencil menu) “a1” AF-C priority selection. Select “Focus” (you may want to switch back to something like “Focus + release” after you’re done with focus-trap shooting). Go to the “a8” AF Activation | AF-ON only | Out-of-focus release | Disable Now, point your camera in the direction of the zone where you want the subject to trigger shooting after it comes into focus. You probably want to set your camera on a tripod at this point, unless you plan on holding the camera yourself. Don’t touch the AF-On button! The trick here is that your camera can’t (auto)focus on its own, because this button doesn’t ever get pressed. Unattended operation: wired remote with shutter-hold feature Hold down the shutter, or use a wired remote that has a locking feature on its shutter release function to keep the shutter release active. The shutter is “held down” until you unlock it. When the subject moves into the correct-focus region, the camera will start shooting until the subject leaves the zone of focus. If the subject re-enters the zone of focus, the camera will start shooting once again. Make sure that you test your setup by waving your hand in the desired focus zone and verify the camera starts shooting. You’d hate to waste an hour waiting for that animal to arrive, only to discover later that you had overlooked something in the setup that caused to camera to ignore taking the shot. Remember to go back to the “a1” menu when you’re done, and restore the original setting you had (such as “Focus + release”). If you don’t remember to restore the old setting, you’ll get burned later when you try shooting and your camera behaves strangely. Many of the flying bird close-up shots require you switch to “M” and set a really high shutter (1/4000 and faster) with Auto-ISO and a stopped-down aperture to get some depth of focus. The Auto-ISO options on something like Aperture-priority mode just won’t go fast enough for the focal length. This mode of shooting causes fairly high battery drain, so be aware of that fact. Charge up your battery before you start up a focus-trap session. Samples Summary You may just find that some types of difficult/impossible shots become do-able with this technique. You wouldn’t make a steady diet of this kind of shooting, but when you need it you need it. You may think that animals wouldn’t be any good at taking selfies with a DSLR, but they may just surprise you.