The following focus stacked composite image was created using a Fujifilm X-T3 mirrorless digital camera and Laowa 25mm Ultra Macro lens mounted on a NiSi NM-200 manual focus rail.
The Laowa lens was set for 2.5x magnification and an aperture of f/4, the “sweet spot” for that lens.
The subject is a small toy dinosaur, viewed from above the anterior end of the dino. The toy is approximately 3.2 cm long (~32 mm).
The carriage of the focus rail was moved 200 micrometers (microns) per step, equal to 20 increments on the NiSi NM-200. A total of 28 photos were taken. A little back of the envelope math shows the carriage moved a total of 5.6 mm from beginning to end.
200 microns x 28 = 5,600 microns
5,600 microns x 1 mm/1,000 microns = 5.6 mm
The camera was set to record JPG plus RAF files. For simplicity the composite image was focus stacked in Adobe Photoshop using the JPG files straight out of the camera. The final output was slightly cropped and sharpened.
Look closely at the full size version of the composite image. I don’t see any glaring “focus banding” so the 200 micron step size seems to have worked. As always, a sample size of one proves nothing. That said, I feel confident the NiSi NM-200 works as expected and will be a useful aid for creating macro focus stacked composite images.
Tech Tips
i used a step size of 200 microns — much larger than the 10 micron precision limit of the NiSi NM-200. My goal was to choose the largest step size that wouldn’t show “focus banding.” I’m not sure what the maximum “safe step size” is, given the settings for my photo gear, but it appears 200 microns doesn’t exceed that value.
Related Resource: “Toy dinosaur” includes a photo (shown below) that shows the entire toy. 2.5x magnification is more than it seems!
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