Focus stacking -- might be a good technique for macro shots of minis

[Spike]

I came across this video on YouTube today about focus stacking, or taking multiple images of a macro subject at slightly different focii and then knitting the images together to get a single image with incredibly deep field of focus. I've not tried it yet, but I will. There is apparently free software out there to combine the images as well. When I saw the video though, the first thing I thought about was the frustration of photographing a dynamically posed mini and always ending up with at least one part blurry.

[Doug Sundseth]

For subjects like miniatures, you're looking at a DoF often down around 0.1mm. (Depending on the aperture, of course.) I'd strongly recommend using a focusing rail (here's a DIY focusing rail solution) to reduce weirdness.

 

With razor-thin DoFs, you'll need quite small movements, so you're likely to end up with dozens of photos. Computer speed and memory start to become very important when managing that much data. (Photoshop does focus stacking OOB, btw.)

[Hibou]

Very cool DiY ficus rail. I think i know what my next project is.

[Spike]

Still haven't DLed the free program recommended, but I thought I would give the basic technique a try on what I would call a "problem mini"...a big beefy orc .. .. with a long spear. I don't own a proper macro lens, but the Canon EF-S 18-55mm f/3.5-5.6 kit lens that came with my camera, when set at its widest aperture and maximum telephoto can still focus on a subject as close as 6 inches.

And since I don't have a focus rail, I tried setting my camera on a tripod and then shooting in tethered mode. That way I can get a nice large preview of the image on my computer and use the tethered shooting onscreen controller to nudge the focus in precise increments without touching the camera. With the model turned with spear facing the camera, it occupies a depth of almost 2 inches, but using the next-to-smallest focus increment, it took 10 shots to stack focus. Once I get the program downloaded and running, I might also try the process with the smallest focus increment and see just how much steam the process will take out of my poor aging laptop.

Also, it would seem to me that a focus-stacking program would be a logical firmware addition to higher end DSLRs at some point in the future.