Many people are under the impression that your camera/lens will auto-focus the same way each time. Nope, nope, nope. Camera designers have to live in the real world of “close enough”, “fast enough”, and “cheap enough”. The holy grail of focus is to make sure your target gets inside the zone of acceptable focus. If your camera misses focus every time (and it probably will), it doesn’t really matter as long as the target is still in focus. I’m going to show you some real-world measurements and what kind of compromises you need to make when evaluating and calibrating your focus. I’m assuming you have a camera that supports focus calibration. It drives me crazy when people make claims about “facts” without the data to back it up and without giving you the tools to repeat the same experiments for yourself. What follows should be reasonably repeatable by anyone, without much expense involved. As always, it bears repeating that “your mileage may vary”. Measurements are affected by the camera, lens, light level, aperture, target size, alignment accuracy, target distance, and stuff I haven’t even thought of. I decided to try the experiment with two different cameras and two different lenses. I chose a Nikon D7100 with my Sigma 150-600 at 300 mm and a Nikon D610 with a Nikkor 24-70 at 70 mm. They’re both competent combinations, and should be representative of what an average camera enthusiast might use. I did all tests with the aperture wide-open, since stopping down would only obscure the results. The Nikon D7100 has a focus sensitivity down to -2 EV, and the D610 has a focus sensitivity of -1 EV. That doesn’t mean you should perform a focus test there. I always use a light level of at least 10 EV for testing. I’m after focus repeatability, and repeatability will go out the window if you shoot in dim light. How far out of the window would be an excellent topic of study for another time. Keeping with the theme of doing things by the numbers, I’m using my go-to analysis software MTF Mapper (version 0.5.13) by Frans van den Bergh. I used the “focus” option with his “mfperspective_a3.pdf” chart, printed to about 10” by 12” and mounted flat. The chart is oriented 45-degrees to the camera, to capture correct depth information. This arrangement gives me ample accuracy for evaluation. By the way, the camera pixel size doesn't matter for this particular test, but you need to remember to set it for the other measurements in the program options. All of my photographs are made with un-sharpened RAW format. I de-focused the lens between each shot, and I alternated between too-near and too-far de-focus to exercise both directions of auto-focus. I always use back-button focus. I didn’t want any directional bias in the shots. What the focus chart looks like. The image above shows what gets photographed and analyzed. The chart left side is rotated farther away from the camera’s plane of focus by 45 degrees. The camera focus sensor is pointed dead-center on the chart. Sample measurement from Nikkor 24-70 mm at f/2.8 and 1 meter. The above picture shows how the MTF Mapper can measure the key elements in the chart and provide focus error measurements. In this picture, the camera missed focus by 2.8 mm at a distance of 1 meter. The camera focus sensor was aimed at the marker that’s under the vertical orange arrows. The depth of sharp focus for this lens/aperture/distance combination is about 15 mm. Anything inside the 15 mm focus window would be “success”. It’s possible to make the measurements using only the red, blue, or green-sensitive sensor pixels in the photo, if desired. Lenses with significant longitudinal chromatic aberration will have focus peaks that are widely separated. For this experiment, all that is needed is to be consistent in using the same settings each time. Sample measurement Sigma 150-600 at 300 mm f/5.6 and 4.22 meters. The depth of sharp focus for this lens/aperture/distance combination is about 45 mm. Anything inside the 45 mm focus window would be “success”. Here, the camera missed focus by 0.7 mm, which is pretty much dead-on. Sample results for Nikkor 24-70mm f/2.8 Test The Nikkor 24-70 mm at 70 mm test follows. It should be noted that this lens is notorious for focusing differently at different focal lengths. This means that it is impossible to “fine tune” focus at a single value and have it correctly calibrated throughout the focal range. I have set a fine-tune value (+16) that under-compensates at 70 mm and over-compensates at 24 mm, with a bias toward 70 mm. The Sigma lens has far smarter firmware in it, and I have it calibrated at 4 different focal lengths and at 4 distance settings per focal length, for a total of 16 calibration fine-tune settings. Measurement Errors Per Photograph (mm): -8.1, -11.2, -10.6, -1.7, -8.4, -7.6, -5, -7.2, -4.5, -6.2, -7.3, -8.9, -1.9, -7.1, -1.1, -7.0, -4.3, 2.8, -2.6 N = 19, MEAN = -5.68 mm, STDEV = 3.55 mm Given a “sharp zone” of about 15 mm (plus, minus 7 mm), I’d say that this test showed a focus miss about a third of the time. The mean of -5.68 mm is my “bias” focus error to help minimize the “+” focus error I get when zoomed to 24 mm. The standard deviation of 3.55 mm is a measure of the typical magnitude of each focus “miss”. Call this repeatability. This is actually an impressive value. That's a typical error of 1 part in 282, or (1000 mm / 3.55 mm). Bear in mind that the 15 mm “sharp focus depth” criteria is actually being quite picky. Also note that the focus chart target was only 1 meter away and the shots were with a wide-open aperture. Longer distances and/or stopping down would make the target zone quite sharp. If I were to expect to spend the day shooting at 70 mm, I’d certainly adjust the focus fine-tune up to the maximum +20, and my focus miss rate would go toward zero. Typical focus error plot, showing it needs more “+” focus fine-tune to drive it toward the vertical blue marker. Sample results for Sigma 150-600 mm f/5.6 Test The Sigma 150-600 mm at 300 mm test follows. In contrast to the Nikkor, this lens has focus fine-tune calibration throughout its zoom and focusing range (16 calibration fine-tune settings). It makes all the difference. Measurement Errors Per Photograph (mm): -0.7, -9.8, -14.5, -16.6, 1.1, 14.5, 0.6, -0.19, 9.4, 4.9, -15.3, 7.0, 4.9, -8.2, -12.0 N = 15, MEAN = -2.3 mm, STDEV = 9.8 mm Given a “sharp zone” of about 45 mm (plus, minus 22.5 mm), I’d say that this test showed it NEVER missed the focus zone. The standard deviation of 9.8 mm is a measure of the typical magnitude of each focus “miss”. Given the focal length and target distance, this is awesome. That's a typical error of 1 part in 431, or (4220 mm / 9.8 mm). Bravo, Sigma. Conclusions If you really, really want to know how your lenses and cameras perform, these tests are representative of how you would do it. Being an engineer myself, I never fail to be impressed at how far photographic technology has come. Twenty years ago, you couldn’t get this level of camera/lens performance at any price. Thanks again, Frans, for your incredible MTF Mapper program. #howto

Many people have purchased a safe to store their camera gear and protect themselves from theft and fires. This might not be the best idea. Let me explain. Safes (mostly advertised as “gun safes”) are usually advertised as being fireproof, typically able to withstand a fire for about a half-hour. How is this achieved? It’s achieved typically in two different ways: via the gypsum in drywall material, or through clay-like materials. Typical fire-rated gun safe with electronic lock Typical gun storage cabinet with key lock This fireproof insulation material makes up the bulk of the wall thickness of a safe. I bet you thought those safe walls were pure steel. Nope. If that were true, a safe would weigh probably triple what it actually does. So why should you care how a safe is made fireproof? The key here is moisture. These fire-proofing materials contain water molecules, and that can create a high-humidity environment. High humidity is not a friendly environment for cameras or lenses. The way these materials work is to convert water molecules into steam during a fire, which keeps the safe’s flammable contents from igniting. A “steamed camera” is probably a dead camera, so fire-proofing won’t really help you anyway. Some, but not all, fire-proofing materials in safes may keep a high-humidity environment inside the safe. The worst offenders here are “document safes”. I used to use one of these myself, and noticed that my camera LCD screen would always fog up when I started using my camera. Not good. Another concern with fire-proof safes is formaldehyde. The drywall insulation material (often from China) might contain formaldehyde. It would be great if you could buy a safe that used Space Shuttle tiles for insulation, but I doubt you could afford it. So, how do you keep your gear secure, without ruining it by high humidity? One solution is a lockable steel storage cabinet. It won’t have insulation that can pose a humidity problem. Steel cabinets can be secured to the floor or a wall via lag screws, etc. Cabinets made for gun storage typically have the heaviest gauge steel, which rival the steel thickness found in modestly-priced safes. These gun-storage cabinets typically have hardened steel, as well. What about storage capacity? You will gain about 4 inches in all interior dimensions for extra storage space if you omit insulation. You will find over time that you ALWAYS need more space. Professional thieves probably have grinding tools that can penetrate most safes without much more difficulty than a steel cabinet. It’s probably more important to protect your gear from humidity and resign yourself to protection against mere amateur thieves. Fire protection? Forget it. #review

Why Lame and Lamer? I can guarantee that the specifications of your secure digital card are bogus. As I'm fond of saying, they're blowing smoke you know where. You'll find that the read speed isn't as fast as the card manufacturer says (lame), and the write speed will typically be even slower than the read speed (lamer). When a manufacturer like Nikon tells you how many frames you have in your camera “buffer”, they assume you have the very fastest SD card available. If you don’t have a fast card, your buffer size is much smaller. What this really means is that Nikon doesn’t have as big of a buffer as they claim; they’re depending upon your SD card to write out the pictures while you’re shooting a sequence. I'll show you how you can test the card for yourself outside of your camera to see how fast it really is. I’m going to demonstrate results from a Windows environment; you can download other free software to perform tests in an Apple and Linux environment, as well. The Windows program "h2testw" can measure both read and write speeds of your secure digital card. If your computer cannot take advantage of UHS-II hardware, you can't accurately assess those newer-generation cards for speed. Newer UHS-II cards have an additional row of electrical contacts on them, allowing for parallel data transmission, which is how they’re able to get so much more speed out of them. Cameras that only have UHS-I capability can still use the UHS-II cards, but they ignore the extra row of electrical contacts and run them at reduced speed. As a result, you won’t ever get beyond the “UHS-I” speed using a “UHS-II” card. If you use a card reader and your computer USB port is USB 3.0, then you may still be able to accurately measure it, assuming your card reader has the electrical capability of the UHS-II specification. Older computers may in fact be too slow themselves to give you accurate information, so be forewarned. Many off-brand SD card manufacturers lie even more than the big guys. The speeds they claim aren’t even close to name-brand manufacturer speed ratings, let alone reality. Buyer beware. Be advised that this (h2testw.exe) program will destroy any pictures on the card, so save existing pictures elsewhere before running the program. You should format the SD card once you place it back into your camera after testing it. h2testw.exe User Interface In-progress program screen SanDisk Extreme Pro 95MB/s test results SanDisk Extreme Plus 90MB/s test results Sample computer "SD card slot" tests: SanDisk Extreme Plus 32GB 90MB/s UHS-I card. Actual Read speed: 69.6 MB/s Actual Write speed: 55.2 MB/s SanDisk Extreme Pro 32GB 95MB/s UHS-I card. Actual Read speed: 66.5 MB/s Actual Write speed: 67.5 MB/s Nikon D7100 results (from cameramemoryspeed.com): SanDisk Extreme Pro 32GB 95MB/s UHS-I card = 69.8 MB/s Conclusions The computer results and camera results are comparable to each other (within 3% for write speed). Compared to the “95MB/s” being advertised for the Pro version, however, these speeds are quite different. Be aware that the newest SD cards (with write speeds approaching 300MB/s) are “UHS-II” or beyond. You’ll have to upgrade to a new camera (like the D500) if you expect to take advantage of such speeds. #howto

Many photo-editing programs include noise reduction, but they’re typically crude. If you’re the type of person that wants the nth degree of control over this process, you might consider using Nik Dfine 2.0. Nik Dfine is a “plug-in”, so that means it runs inside of another program. Many programs, such as PhotoShop, LightRoom, Aperture, and Zoner Photo Studio can use plug-ins. If you use Nik Dfine, it means you get the same user experience inside any of those programs that can run it. Nik Dfine comes from Google, and they decided to discontinue it; they made it free, so you can’t beat the price! Google also discontinued the other Nik plug-ins, so they’re all free now. You may need to consult Google for specific procedures on how to install the Nik plug-ins for your particular program. You can still get the plug-ins here: Why would you want noise reduction in the first place? Two of the biggest reasons that come to mind are small-sensor cameras and dim light pictures where you were forced to really crank up the ISO. Those color spreckles, especially in deep shadows, can look terrible. You should know that the order in which you process your pictures is important. You want to handle noise reduction first, before any other photo manipulation. By the way, you want to handle sharpening last. In-between these two editing operations, order isn’t too important. I noticed that the Dfine user guide said it supports only Tiff format, but I used it in Zoner Photo Studio with Nikon NEF format pictures, so you don’t have to worry about that constraint. A little noise reduction goes a long way, so you don’t want to overdo it. It you don’t heed this advice, you’ll probably end up with pictures that have a lot of mush instead of fine details. If you’re working with “raw” format, then don’t apply any sharpening or noise reduction before using Dfine on the image. Nik Dfine is extremely smart about how and where it rids noise. It can aggressively attack featureless areas and barely touch areas with fine detail. You can go as manual as you wish to “take control”, or you can let Dfine do its magic automatically. Personally, I love the automation and the end results. Many photographers find that they hate the color noise, but that they don’t mind the luminance noise. I (mostly) fall into that category. I don’t mind the gritty or sandy effect luminance noise can have. Leaving luminance noise alone can result in an overall sharper-looking photo. If you want to rid both types of noise, however, Dfine can deliver. The Dfine developers were very smart about leaving the fine details alone while smoothing the out-of-focus areas. Dfine is essentially a two-step process. The first step is “Measure”, where it analyzes the photo and decides what to do and where to do it. The second step is to act on the noise, or “Reduce”. Before working on noise reduction, you will probably want to set up some preferences. I prefer the “single” versus a “split” or “side-by-side” view of the photo, and I toggle the “Preview” checkbox to see the “before” and “after” effect on the whole photo. I also prefer the default “RGB Mode”, versus modes such as “Chrominance Only” or “Luminance Only” (which switch to black-and-white). I like to keep the “Loupe” enabled, so that I can selectively look at the pixel-level wherever the mouse pointer is. You can also lock its view into a position of your choosing by selecting its “pin” icon. Some notes on setting up the Dfine functionality “Measure” showing Automatic mode Again, click on “Measure” to let Dfine analyze the photo and determine its game plan on how to reduce noise prior to clicking “Reduce”. “Reduce” showing “Color Ranges” Method. After clicking “Measure”, the interface will change to allow you to fine-tune settings. I typically will increase the “Edge Preservation” (under the “More” drop-down) to save really fine details, such as fur or feathers. For global changes based upon color, select the “Color Ranges” Method. If you wish to work on areas of the picture, you can select “Control Points” instead, and add as many as you need. People familiar with Nikon Capture NX2 know all about control points, since Nik wrote that program, too. When you’re happy with your noise reduction setup, click on “Reduce”. Example noise reduction at pixel-level zoom Typical noise (in shadows) Noise reduced without detail loss in fur As camera sensors get better, noise reduction is needed less and less. But when you need to fix a noisy image, Dfine is a great tool to have in your arsenal. #howto

There’s a lot of web discussion about using SnapBridge with the D500, mostly centered on being able make it work or not. My own interest in SnapBridge is related to why I might want to use it at all. I’m probably in the minority here, but it’s more useful to me to be able to remotely trigger the shutter than to be able to transfer photos to my phone. The Nikon “pro” cameras have the infrared-trigger feature conveniently removed. I guess it’s convenient to somebody; I suspect that somebody is Nikon only. So the cheap and easy IR shutter control (via the little ML-L3 remote or via a little app running on your smartphone) is out. Let’s review some ways you can remotely trigger the shutter on your D500 (and most other “pro” models). The most versatile (and therefore the most expensive) way to remotely trigger your camera is the Nikon WR-1 wireless remote. It has a range of 394 feet, has a zillion options, and costs about 470 bucks. Ouch. But if you’ve got your camera at the feet of horses finishing the Kentucky Derby while you’re in the stands, then this is the ticket. If you can get within about 66 feet of your camera, then the Nikon WR-R10/WR-A10/WR-T10 can trigger your shutter and also control your flash without wires. The cost is around 200 bucks. If you can get within about 3 feet of your camera, then you can use the Nikon MC-30A 10-pin wired remote, at a price of about 65 bucks. Or, like me, you can get a cheap 10-pin wired remote (I got the Vello RS-N1II) for about 8 bucks. Now we’re talking. Plus, you can control it with just one hand, and you don’t even have to be looking at it. Enter SnapBridge. So, how can SnapBridge help me to take photos remotely? After you download SnapBridge to your phone (mine is a Samsung Galaxy S6 running Android 6.0.1) and then connect via wireless, you can select the option for “Remote Photography”. I'd suggest you visit the Nikon website to watch the SnapBridge video. Now, via SnapBridge, you can not only trigger your camera, but you can get Live View right on your phone’s screen. You can’t (as of this writing) alter exposure settings, but as least you can see what settings your camera is using and you can also see the battery level. You’ll notice that your phone’s “live view” will give you the impression that it has just consumed several espressos. It has the jitters. Note that you may want to use SnapBridge wireless in limited doses, because once your camera is out of “Airplane Mode”, it will cause pretty heavy battery drain. At least you can monitor that drain from your phone. The owner’s manual says you can use the D500 wireless from “approximately” 10 meters. I got out a tape measure, and successfully controlled my camera from 30 feet. Not that I’m a skeptic or anything. I wouldn’t suggest you try using a drone with this, but seeing through your camera and shooting from 30 feet away could open up some pretty creative possibilities. SnapBridge in “Remote Photography” mode. Note above how you can monitor shutter, f-stop, shots remaining, and battery level while shooting. The shots you take will show as thumbnails below the camera settings. The big white circle is the shutter button. What the camera sees while being controlled by SnapBridge View the SnapBridge training video at the Nikon web site My own preference for most remote-release scenarios. Cheap and reliable 10-pin connection. I would imagine that SnapBridge will get some enhancements in the future. Let’s hope it will someday enable you to alter exposure settings from your phone. By the way, if you're more interested in transferring photos to your phone and skipping the remote control, you can use BlueTooth. It's slower than wireless, but uses a tiny fraction of the battery power to operate. Don't forget to activate your phone GPS to embed the location data in the pictures. #review

I have read for many years in marketing literature about how some camera’s viewfinder is “bright”. What does that mean? How would you know if your camera viewfinder is bright or dim? I prefer numbers to hand-waving. After pondering the issue for a while, it occurred to me that most of us possess an instrument to readily figure out what bright means. Our phones have a built-in camera, and photos from those phones contain EXIF data. EXIF data can be inspected for the “brightness”, which is called “Light Value” (EV). Recall that 1 EV difference equals 1 stop of light. I use the free program called “exiftool” to inspect the EXIF data. A link where I give more details on this program is here. Taking a look at the EXIF data from a phone photo, it’s packed with useful information. Note that this Samsung Galaxy S6 phone has a 4.3mm, f/1.9 lens. Because of its teeny sensor, that’s the equivalent of a 28mm lens with a 65.5 degree field of view. Also note that the EXIF data shows a “Light Value” (8.4 shown above). Why use your phone camera? Because it has a huge depth of focus and the lens fits neatly within your camera viewfinder while blocking external light. If you use the same lens, aperture, and lighting conditions on each camera, then you can take a picture using your phone through different camera viewfinders and compare them for brightness, via the “Light Value” in the EXIF data. In the comparisons below, I took a look at the Nikon D610, D7000, and D500 camera viewfinders. I expected the D610 viewfinder to be the biggest and brightest, since it has a full-frame sensor. I was wrong. The D500 is better. Please forgive the poor exposure in the phone photos below. It's not as smart as Nikon, and the large black expanse fooled the meter. I'm only interested in brightness (EV) and size in the frame, so the exposure technique just needs to be consistent for each camera viewfinder. Nikon D610 Viewfinder. EV 8.4, 35mm Nikon D7000 Viewfinder EV 8.1, 35mm Nikon D500 Viewfinder EV 8.8, 35mm Cropped view of D610 viewfinder Cropped view D7000 viewfinder Cropped view D500 viewfinder Viewfinder Comparisons The D610 viewfinder is EV 8.4 and the view width is 1896 pixels in the photo. The D7000 viewfinder is EV 8.1 and the view width is 1694 pixels in the photo. The D500 viewfinder is EV 8.8 and the view width is 1930 pixels in the photo. It struck me that the D500 viewfinder looked bright and large, but I didn't know if it was a psychological effect or real. Now I know it's real. I was surprised to discover that it's even larger and brighter than my full-frame D610 viewfinder. Try this test yourself; it's an easy way to compare camera viewfinder brightness, magnification, and even focus sensor sizes and focus sensor converage. #howto

How does the D500 stack up shooting infrared? The last pair of Nikon cameras I evaluated shooting infrared were big disappointments: the D7100 and the D610. They had terrible internal reflections that would ruin most infrared shots, which requires use of the DK-5 viewfinder eyepiece blocker to avoid this problem. A link to those results (and the good D7000 results) are here. The D500, on the other hand, is excellent shooting infrared. Ironically, this camera has a built-in eyepiece shutter, although it is probably only needed to help with exposure measurement accuracy on a tripod. I use a Hoya R72 filter for infrared shooting. Something I consider to be very ironic: probably one of my best lenses for shooting infrared is the lowly 18-55 kit zoom (I’m using a VR model). Most other lenses I have tried that shoot wide angle either have a nasty hot spot in the middle or aren’t as sharp. I pretty much park the lens at 18mm; if it went wider, then I’d zoom wider. Here’s the best site I know for evaluating which lenses work for infrared, and also for the f-stop range that works. Even my 24-70mm f/2.8 VR 'E' zoom is crap for infrared. As a little side-note, many lenses perform fine with infrared until you stop them down too far. Up through f/8, they may be fine, but then start to exhibit the central hot spot. My Nikkor 50mm f/1.8D, for instance is okay until about f/8. Nikon seems to try pretty hard to keep people from shooting infrared. The D500 image sensor filter screens out IR very effectively, and exposure times are pretty outrageous. This totally precludes using a direct-measure, pre-set manual white balance (which by the way works perfectly fine on older cameras like the D50 and D60). My open-shade shots are made in the vicinity of ISO 100, f/8, 30 seconds. When you add in long exposure noise reduction, you literally need a lot of time on your hands to do this kind of photography. I like to manually set a gray point by selecting a rectangular picture area (in Nikon Capture NX2, it’s called a ‘marquee sample’) followed by severe hue-shifting. When I use something like Photoshop, then I typically perform a red-blue channel swap instead of the hue-shift. There are plenty of web articles on this topic. Enough talk. Let’s see some actual D500 results. #review

Short answer: yes. But you know there’s a catch. There’s always a catch. So here it is: garbage in, garbage out. The ‘secret’ to getting great results for focus calibration is multi-faceted. You must use the proper focus target, your camera must be very stable, you need consistent technique, you need to decide on a zoom setting, you need to pick a target distance, you may need to pick an aperture, and you must use good lighting. As much as people hate to hear this, it’s a fact of life that measurement and calibration always involve statistics. Your gear isn’t perfect, so you are guaranteed to get some variability in measurement. Focus calibration isn’t a “one and done” scenario. Many measurements are required, and then you have to find the average value. You might also have to throw out the measurement values of outliers. The Nikon D500 “automatic” focus fine-tune calibration assumes that your live-view, contrast-detect focus is dead-on. It compares the distance your phase-detect focus system decided to focus on a target to the distance that the contrast-detect focus system decided to focus on that same target, and then calculates the fine-tune value that would shift the lens phase-detect focus to match the contrast focus. Depending on which direction (near-to-far versus far-to-near) your lens travelled to obtain focus, you may get a different calibration answer. Depending on what your selected focus point ‘sees’ as being the subject, you may get a different answer. Depending on your selected lens aperture (mostly high-speed lenses), the answer may vary. Depending on the zoomed focal length, you can get a different answer (think parfocal optics). Depending on the target distance, you can get a different answer. In dim light, you can get a different answer. The physical lens focus mechanics have some slop. So don’t expect miracles here. You need to decide on your favorite zoomed focal length, distance, and aperture to use while conducting the test (depending on the type of lens being measured, of course). You need to use a proper focus target that has absolutely no ambiguity about what the “target” really is, from the standpoint of your focus sensor. Sigma is savvy to these ugly facts of optics life, and provides their newer lenses with the ability to calibrate zooms at multiple focal lengths and multiple focus distances. Their (inexpensive) USB dock and free software lets users reprogram the lens firmware with this calibration information, in addition to letting users select focus algorithms, upgrade firmware, select anti-vibration modes, and other features. Nikon is not savvy, but I digress. I use a specific focus target, rotated to a 45-degree angle, to calibrate focus. The target design, and its associated analysis software, was created by Frans van den Bergh. I wrote an article to explain his software and focus target here. The recipe to perform a single calibration measurement on a D500 goes as follows: ⦁ Lens VR OFF ⦁ Focus mode set to AF-S ⦁ Select the center focus point ⦁ Camera/lens on sturdy support pointing at the focus target ⦁ AF fine-tune ON in setup (wrench) menu ⦁ Live View mode ⦁ Normal-area AF ⦁ Focus on the target. Focus point centered on an edge illuminated by bright light. ⦁ Press the “AF Mode” button and “Movie Record” buttons simultaneously and wait patiently for about 3 seconds. Don’t wiggle the camera… ⦁ Highlight “Yes” and press “OK” when prompted. The calibration value will be written for the lens in the usual AF fine-tune menu location. Rinse and repeat. The focus target using the MTF Mapper program, showing measurement labels on squares Note in the photo above that the camera focus point is centered on the right-hand vertical edge of the large black target. There is no ambiguity about what it is focused on; the focus point can only see a single vertical high-contrast edge. The MTF Mapper program measures the resolution of every black square it finds, and lets the user easily see where the optimal in-focus squares are located relative to the large black central target right-hand vertical edge. Using this software, you can visually see where the sharpest edges are located with each test you make (the edge labels eliminate any judgement calls you’d have to make in an un-labelled photo). After each AF fine-tune measurement is done, write down the value saved in the AF fine-tune menu for the lens being used. Take several measurements and average their values. You may have to throw out any wild readings first. These readings will give you a feel for the natural focus variation of the lens. I like to manually change the focus to alternate between near and far for each test, prior to initiating AF-S auto-focus. This will let you explore any bias that the lens has for focus direction. Manually enter the averaged fine-tune value for your lens in the AF fine-tune menu. This will give you the best “typical” focus result. An MTF Mapper “profile” plot of the focus chart photo. Note “AF Tune Value” is displayed in the plot above. The D500 focus calibration feature automatically saves this value in your camera. The MTF Mapper program extracts the value from the focus chart photo EXIF data to add it to the plot. Conclusion I used this automatic fine-tune calibration feature dozens of times, and the fine-tune value tracked the actual phase-detect focus error quite well (within about 1 or 2 counts). The problem is that it can only calibrate against a moving target. Your own lens natural focus variation will prevent you from ever getting “the” calibration answer. In my own testing, I would get an auto-calibration tune-value variation of about plus/minus 3 for a typical lens. This is roughly the same as my own manual calibration best efforts; it would get within about 1 or 2 counts of what the software measurement software determined to be "best". I have read reports that some users get terrible calibration repeatability, but I suspect that may be largely due to using a poor focus target and/or sloppy technique. I don’t think that phase-detect can ever compete with Live View focus accuracy across the board, because it cannot address issues related to focus-shift-with-zooming, focus-shift-with-distance, or spherical aberration effects. None the less, I applaud Nikon for adding this feature. Now if they could match Sigma lens firmware capabilities, they’d really be leader of the pack. By the way, now even the Samyang (Rokinon) company has added the same firmware-programming features that Sigma offers. Oh, and one thing I'd definitely change with their auto-calibration is the two-button-press thing. There's no way to keep things rock-steady doing that. They need to make it an operation you can do using a remote trigger or timer so that you don't have to jiggle the camera. #review

I was trying to solve a mystery about why my trusty Sigma 150-600mm seemed to lose its ability to resolve fine details. I recently got a D500 and was using the Sigma while testing the camera electronic front-curtain shutter feature (to totally eliminate vibrations). I noticed the resolution measurements (using the MTF Mapper program) were much lower than expected. Had I somehow bumped the lens and knocked the optics out of alignment? Was the camera focus system not functioning properly? Were the phase-detect and contrast-detect focus systems both out of whack? Was my vibration reduction accidentally left on while using a tripod? Am I getting sloppy and don’t even know it? Other lenses weren’t showing any resolving problems on this camera, but that only helped to show what the problem was not. Out of desperation, I removed the 95mm Hasselblad UV filter from the Sigma. Like magic, the resolution numbers were back to where I expected them to be (more than 20% higher). Are you kidding me? My premium Hasselblad filter is no good? I don’t have any other lenses that use 95mm filters, and I don’t have any step-up rings that big, either. I finally figured out how I could use my 24-70mm lens with its lens hood to hold the filter via friction-fit inside the hood. I took shots of my resolution target with this filter in place (at 70mm), and then removed it to repeat the shots with no filter. The MTF Mapper program showed zero resolution differences either with or without the Hasselblad filter! How is this possible? How can the Hasselblad show perfection on this lens and wreck the resolution on the Sigma? I don’t have any other long lenses to experiment with. I don’t think most users of really big glass use filters at all, except for the kind that fit in the drop-in filter holders near the rear of the lens. Maybe there’s a good reason they don’t use front-mounted filters, aside from the big cost and added weight. Let’s take a look at some resolution test measurements. The following plots compare shots taken with and without the Hasselblad 95mm filter. Sigma 150-600mm at 600mm with 95mm Hasselblad UV filter. Bad resolution! Sigma 150-600mm at 600mm without UV filter. Much better resolution. Note in the above plots that the peak resolution with the filter in place has an MTF50 of about 28 lp/mm. The plot of the photo taken moments later under the same conditions, but without a filter, has an MTF50 peak resolution of about 36 lp/mm. That’s a difference of about 22%. I repeated this same test a dozen times, with the same results. This would lead most people to conclude that the filter is absolutely terrible. But I'm stubborn. I investigated further. Next, I’ll show you some resolution test results using my Nikkor 24-70mm f/2.8 VR lens. 24-70 at 70mm f/2.8 with Hassleblad 95mm UV filter 24-70 at 70mm f/2.8 without filter 24-70 at 70mm f/2.8 without any filter 24-70 at 70mm f/2.8 with Hassleblad 95mm UV filter Maybe you can tell a difference between the measurement results with or without the filter, but I sure can’t. Based upon the tests with the 24-70 lens, I would have to conclude that there’s nothing at all wrong with the Hasselblad filter. I was taught that even a medium-quality filter would have a negligible effect on lens resolution, although it might increase light reflections or decrease light transmission. This is a whole different ball game. I now have a strong suspicion that even top-quality front-mounted filters on really long lenses have a big negative impact on resolution. Take my experience with this filter/lens combination as a heads-up. I mainly use UV filters as cheap insurance against accidents and because they’re easier to clean than the front lens element. From now on, though, I’m just going to rely on the lens hood to protect this Sigma lens. If I ever get a short focal length lens with a 95mm filter thread, I wouldn’t hesitate to use the Hasselblad filter on it. For long lenses, though, beware of filters over the front element. At least do some careful testing before you decide to permanently park a filter in front of your big lens. I can’t help but wonder if there are a lot of people out there that are disappointed in their long lens and don’t know that the blame lies in their filter. #review

In a previous article, I discussed software to accomplish focus stacking. I glossed over the hardware that lets you get real quality results. I’m going to try to rectify that shortcoming in this article. I’m assuming you’re interested in macro focus-stacking. For those that are unaware of what focus-stacking is, it involves taking multiple photographs that you combine to get greater depth of focus. Macro photography is famous for suffering from paper-thin depth of focus. Optical physics is against you here, but software and digital photography comes to the rescue. What you need to accomplish macro focus-stacking is flexible close-up gear. If you check on web sites such as e-bay, and you shoot Nikon, you should be able to locate a bellows setup like mine, the PB-4. I also use rings that let me reverse the lens and attach a filter to the reversed lens. Nikon stopped making bellows hardware decades ago, because the customer base was just too small to make it worth it to them. Some camera bodies may not allow attachment to the bellows; it depends on how much overhang the “pentaprisim” portion of the camera has. My D610, for instance, barely fits, but the D500 fits fine. Battery grips, however, don’t allow you to connect or properly use the bellows. You may need to set the bellows into ‘vertical-shooting’ format to be able to mount the camera body; crank the camera-mount portion of the bellows to the rear-most position to mount the camera. I still use the vintage 55mm Micro-Nikkor f/3.5 lens, circa 1974. Think this old lens couldn’t cut it today? Think again. With focus-stacking, you should always set the sharpest lens aperture (f/8 for the Micro-Nikkor). Remember, stacking will take care of depth of focus, so you don’t need to worry about stopping the aperture down to get sufficient depth of focus. When you get into magnifications greater than life-size, you should reverse the lens to get the best optical results. I use the BR-2 lens reverse ring (52mm). Any other macro lens I have access to doesn’t have the 52mm filter thread, so lens-reversing isn’t an option. Wind and vibration is the enemy, so you will get best results in dead-calm conditions (such as indoors). I made a custom piece of hardware that fits into the end of my bellows unit; it has an alligator clip to hold small objects at whatever height and rotation I need. This clip hardware is connected to the bellows, so image motion relative to the bellows is virtually eliminated (it would move the same as the camera). The clip can also hold a little platform in front of the lens, allowing you to lay small subjects that aren’t “clip-able” onto the platform. Lighting is crucial. I often use an LED ring light, which stays cool and provides perfectly even lighting. When my lens is reversed on the bellows, I attach a BR-3 (52mm filter thread) ring to the rear of the lens. I can slip the ring light over the BR-3. The light won’t fit larger diameter lenses. Continuous lighting is really, really nice to see your subject well. I use a remote or wired release, and I set the camera up in the mode to make shooting a two-step procedure: the first release flips up the mirror and the second release triggers the shutter. Electronic front curtain shutter mode is ideal, if your camera supports it. I rotate the focusing knob on the bellows to shift the camera/lens combination toward the subject in increments of about 0.1mm for higher image magnifications. I’ll typically take about 50 shots to stack. The zone of sharp focus should overlap from adjacent shots. Be careful to never change the image magnification while shooting a focus stack. Focus-stacking is mostly incompatible with living subjects at high magnification, since image motion is verboten. Some people claim they can chill insects enough to temporarily stop their movement. In the demonstration shots below, I found a recently deceased bee and a beetle to use as a subject. Due to the way stacking works, you won’t want to use tight framing on your subject. Expect to lose about 20% of the image around the edges, which you’ll need to crop out of the final stacked image. Reverse-mounted lens with ring light and clip to hold subject I don’t have hardware to reverse my other macro lenses, so the above setup only applies to the 55mm Micro-Nikkor with its 52mm filter thread. This ring light only fits 52mm or smaller diameters. Note how the hardware that holds the small subject is connected to the bellows; subject motion is no longer a problem in still air. The LED light provides perfectly even illumination without heating up the subject. For really gung-ho macro photographers, the PB-4 bellows provides both tilt and shift controls to manipulate the plane of focus and also perspective. Focus stacking pretty much eliminates the need to alter the plane of focus, though. Flash close-ups with AR-4 release, BR-4 diaphragm control The above setup demonstrates using a flash instead of a ring light. For lenses that cannot be reversed, I use this lighting arrangement if the subject is far enough away. At higher magnifications, the lens will eventually cast a shadow on the subject. This arrangement doesn’t provide continuous illumination, so the AR-4/BR-4 arrangement can be handy to keep the lens diaphragm opened until you depress the plunger on the AR-4. This cable release was designed for cameras like the Nikon F2, where the second cable would connect to the shutter release. D500 with wired remote. Subject is lit up. Focus stack of 69 photos. 55mm Micro-Nikkor at f/8, Nikon D610. The demonstration photo above was made with the lens reversed and the ring light for illumination. Each shot was made in manual mode, ISO 100 and 1/3 second. You want the sharpest aperture and lowest ISO for this shooting, and please, please use RAW format. Using good light and an optimal aperture, this stacking technique gives you an idea of just how good the 55mm f/3.5 Micro Nikkor lens is. As I mentioned in another article, they used this lens for shooting the original Star Wars film, with good reason. Film cannot compete with this form of digital photography. I think that focus stacking is the perfect blend of art and science. Happy stacking. #howto

Have you ever had to make a decision on which wide angle lens gets to go on your trip? The loser is usually the fisheye lens. Fisheye lenses are just a little too specialized, so they often fall into benign neglect. What if you could magically turn that fisheye lens into a regular rectilinear super-wide whenever you wanted? Would you find that useful? Duh! I found that I got caught flat-footed in keeping up with lens distortion correction technology. I tried using the lens “profile correction” in Adobe Lightroom with my Rokinon 8mm fisheye, and my jaw dropped. Words can’t do it justice, but pictures can. There are other software vendors, of course, that can do this task even a little bit better, because they can salvage more of the left and right frame edges. But I have Lightroom and I don’t have those other tools. And believe me, there’s plenty of image remaining after the lens profile corrections. Check out my Rokinon 8mm fisheye review here. I discussed a few postprocessing operations to ‘straighten’ shots in the article, but the results left a lot to be desired. The images (at f/8 and beyond) are incredibly sharp. But the lines are curvy. Very curvy. Boring chart in Lightroom before lens profile correction, usual fisheye effect Boring chart in Lightroom with lens profile correction. Rectilinear super-wide! I am thoroughly impressed at how much barrel distortion is corrected. All of those little squares are square again. Yes, you lose some frame edges, but what’s left still covers a huge angle. For all intents and purposes, your fisheye image is now looking like a typical rectilinear super-wide lens. I cannot guarantee that other brands of fisheye lenses will be so well corrected. You can consult the Adobe web site to see if your lens profile exists. The profiles are periodically updated for new lenses. The profiles are available in Photoshop, as well. Lightroom steps to use lens profile corrections for Rokinon Select the "Develop" portion of Lightroom Remove chromatic aberrations (select) Enable Profile Corrections (select) Make: Rokinon Model: Rokinon 8mm f/3.5 UMC Fisheye CS Tokina 11mm. I used to think this was a pretty wide angle lens. Rokinon 8mm with Lightroom profile correction. Now that’s wide. I chose the above shot to drive home the point that even though you can get super close and super wide, it doesn’t mean that it’s always the best choice. The lens distortion is removed, but the extreme perspective isn’t welcome in every shot. I consider this shot to show a lack of ‘taste’. Now, imagine if a person was sitting in one of those near chairs. Scary. Even with liberal cropping, you can now go really, really, wide. Rokinon 8mm with no profile corrections. Now that’s a REALLY wide fisheye. I think that these lens profile corrections are going to give my fisheye a whole new lease on life. All of those curvy lines can be made nearly dead straight. Claustrophobic spaces can be made to look immense. As with all super-wide angle lenses, you still need to pay attention to getting perspectives that are too extreme. Shooting discipline is even more important here, such as keeping the camera level and at a ‘respectful’ distance from the subject. But imagine the world of options that this technique can open up. Science and art live happily ever after once again. #howto

So what do you do when you get a new Nikon camera and discover that Capture NX2 barfs on your .NEF files? There may be no need to panic. This is definitely a niche article. I am an admitted Capture NX2 holdout. I know there are others in the resistance movement out there, at least in other countries. I refuse to abandon either raw format or Capture NX2. It’s well-known that Capture NX2 doesn’t understand new Nikon camera raw files. Maybe you, like me, don’t want to switch to TIF or Jpeg to keep using Capture NX2. To find out if you’re in luck, you need to check to see if you have a copy of Capture NX2 Version 2.4.6 (not the last one that is 2.4.7). No? You might have a lot of difficulty finding it, and Nikon won’t be of any help here. I'm a packrat when it comes to computer disk backups, so I had pretty much every Capture NX2 version saved. Next, you need to download the (free!) “Raw2NEF”, created (and maintained as of this writing) by Miguel Bañón. His download site is here: Miguel is supporting both Sony and Nikon cameras. The (growing) list of supported cameras is listed at his site. What’s the catch? Well, there are two. First, this slightly disrupts your workflow. Now, you have to run his program and do the conversion before using Capture NX2. Second, the NEF files that the Raw2Nef program creates are about triple the size of your original compressed NEF files. You can always "zip" the folder of converted files later, to save about 33% on disk. You don’t have to worry about the Raw2Nef program altering your original files; it just makes new files (CNX2_ prefix) where you tell the program to put them. It only takes about 1.5 seconds per shot to do the conversion on my own computer. There are other options to fine-tune the file conversion process, but I just select the input folder, the output folder, and then click convert. It can recursively run through sub-folders during the conversion process, but it places all of the converted files into a single directory, so just be aware of this. If you have Photoshop CS6, you can later select the "CNX2_" files and convert into Photoshop-compatible files. You should click the "Adobe Photoshop" button and browse to where Photoshop.exe is located before doing the conversion. The Raw2Nef interface Thank you Miguel! And long live Capture NX2. #howto