Hand-held Macro Focus Stacking that Really Works
After fussing with tripods and unsuccessfully getting near to low-level macro subjects, I figured there must be better way. I finally found it: how to hand-hold my D850 to get good stacked macro photos.
If you have tried to get near to small subjects that are close to ground level using a tripod, you know the pain. Tripods are too unwieldy for most macro shooting outside of the studio. Focus stacking just magnifies the problem. Sorry for the weak pun.
For the article that follows, I used the Nikon D850 focus-shift shooting feature. Not many cameras offer this functionality, but if you like to do focus stacking then you might want to consider this feature in your next camera purchase. Even if you only do single-shot macro photography, the gear idea shown may still prove useful to you.
Hand-made rifle stock
This isn’t a brand-new idea, but I decided to see if I could make a rifle stock that could hold my D850 with the Micro Nikkor 105mm f/2.8 lens. It’s just too hard to hold the camera/lens combination steady enough for macro photography without some help. I found that I could hold the camera “reasonably” steady using a custom rifle stock, but by no means rock solid. There are a few variations on this rifle stock idea out there on the internet you might be able to purchase if you don’t want to try to make one yourself. My design allows enough clearance to attach my LED ring light onto the front of the lens.
I got hardware that acts like a tripod screw (1/4-20 thread) to attach the camera to the rifle stock. I attached a littled wheel to the screw to use as a tightening knob. You can take a look at regular tripod screws to see how the hardware works. Again, you can do web searches for ready-made parts if you don't want to make anything yourself. The camera grip base sits in a shallow depression that prevents any camera rotation on the stock.
I use the free Windows-based CombineZP program to perform focus-stacking, and I have learned through experience that it’s remarkably good at aligning a stack of photos that have significant side-to-side misalignment. What it can’t do well (and no software can) is fix uneven front-to-back focus shifting. There’s no correction for gaps in a stack of photos where nothing is in focus. It’s crucial that you have overlapping sharp-focus slices in your photos, or else the stack will be ruined. Your main enemy outside is invariably the wind buffeting your subject.
I found that my 105mm at f/8 (infinity focus) needs a focus shift size of ‘6’ to always get proper shot overlaps with the D850 using focus-shift shooting.
The rifle stock with a little monopod-style front attachment lets me easily control and nearly eliminate the front-to-back wobble problem. I still get a fair amount of side-to-side wobble, but that’s almost no problem at all for CombineZP using its “Align and Balance Used Frames (Quick)” macro.
If the subject is a little higher off of the ground, then I sit on the ground and rest the little monopod piece on my leg. With the monopod piece resting on something and the back end of the stock resting against my shoulder, it’s enough to mostly eliminate front-to-back motion. And using the rifle stock, I can get as close to my subject as I need.
This scheme depends upon the D850 focus-shift shooting feature, however. I give the camera the go-ahead, and it takes all of the shots automatically while I just hang on for the few seconds it takes to take the stack of photos. If I had to manually either shift focus or move the camera forward shot-to-shot, I don’t think I would ever get a suitable focus stack.
I used to get focus stacks using my Nikon PB-4 bellows that has a focus rack. This setup demanded a steady tripod and careful, even turns of the focus rack adjustment knob to get an acceptable focus stack. It was slow and tedious, but it worked. The D850 makes this task trivial in comparison.
But the proof is in the pudding, as they say. The following example is using a stack of 20 photos, shot using the rifle stock. The CombineZP program can’t use RAW photos, so I first convert them into TIF format (I used CaptureNX-D to batch-convert them). CombineZP sometimes has problems with full-size FX images in the TIF format (around 350MB each!), which changing to DX mode solves.
Set up CombineZP program to show its menus
Click on File | *New to select the TIF file stack folder
Pick the photos to stack
CombineZP dialog after photos are loaded
Select the “macro” that aligns your shots
Select the macro to stack the aligned shots
Draw a rectangle to select the stacked result portion to keep
Use the mouse to select a rectangle around the final stacked image that avoids the portion that looks like a reflection.
Select File | Save Rectangle As and save the result as TIF format for the best quality. There are other file formats, such as jpeg, that can be used, too.
The finished stack of 20 shots
The methods I have outlined make it easy and flexible to get your stacked photos. Let’s face it: unless it’s reasonably convenient to do, you’re going to avoid making stacked shots. My D850 on a rifle stock has made shooting these shots really easy.