Pair #1:
Pair #2:
The subject here is a paper wasp mandible, total frame height 1.8 mm.
If you're like me, you probably have trouble telling the difference between the two pairs. The first one has a little more halo around the edges of the mandible. It also has a little less "shimmer" in the center of the mandible where those big reflections are, and around the ball joint at the base, and especially on that OOF light stuff at bottom right. Pretty minor differences, visually.
The exciting part comes in how each pair was produced. Pair #2 is traditional true stereo, two stacks shot about 6 degrees apart. But pair #1 is completely synthetic, made computationally by Zerene Stacker from a single stack.
The button-pushing of how to do this is described at http://zerenesystems.com/stacker/docs/S ... Stereo.php.
Very briefly, you tell ZS to run the stack two or more times, introducing a bit of "shift" each time to make the composite image look as if it were shot from slightly different viewpoints. Then you take the resulting composites and make a stereo pair, or a movie, or maybe even a stereo movie.
Synthetic stereo has several important advantages over the traditional scheme of shooting two actual stacks. These include:
- You get stereo almost for free -- no additional time to setup or shoot, and no additional space for image files.
- You can even reprocess old stacks that you shot with no intention of ever doing stereo.
- You can get stereo even when shooting through an ordinary microscope that only provides one view.
- The left and right images are guaranteed to correspond -- no problems with different stack depths, different magnifications, different stuff in the background, and so on.
- You can orient the subject however it's convenient to illuminate and shoot, then display it however it looks best. (With the traditional scheme, you can't change the orientation after you do the shoot.)
It also has the quiet charm of working best when you need it most, with high magnification deep stacks that have shallow DOF per frame.
All images shown here were done with Zerene Stacker PMax.
The two pairs shown above are full frame and are unretouched except for framing and sharpening.
The following two pairs are cropped less than full frame, using StereoPhoto Maker, but also are unretouched except for framing and sharpening. Both are "from the archives", originally shot with no intention of producing stereo.
My friend the Hobo Spider. Field width shown here is 6 mm.
Some "Tinier spring flowers", field width 2.5 mm. (Yes, these are very small flowers!)
The flower example is especially interesting because the background looks "flat". That's because all of the background pixels essentially come from one frame -- the farthest one back -- so they all have the same disparity and thus the same apparent depth. If you're shooting a new stack with intention of rendering in stereo, and you have some texture in the background, you might want to shoot a few extra frames behind the subject to get some separation between subject and background in the stereo rendering.
A couple of other recent examples that I posted out without explaining include the "Spectacular spider-killer-killing wasp" and the earlier paper wasp mandible shown HERE.
I hope you find this interesting -- it was fun preparing them.
--Rik
Photography details:
- The paper wasp mandible was shot with Canon 300D camera using a Nikon CF N Plan Achro 10X NA 0.30 objective on 200 mm extension, 0.00033" focus step, stacks of 101 to 118 frames. Illumination was with dual 60-watt desk lamps through a Kleenex tissue diffuser.
- The hobo spider face was with Canon 300D camera using Olympus 80 mm bellows macro lens with Olympus 170mm matched auxiliary lens, marked f/5.6. Halogen dual fiber illuminator with kleenex tissue diffuser. 61 frames spaced at 0.005".
- The spring flowers were shot with Canon 300D camera, Olympus 38mm bellows macro lens at f/5.6, 39 frames at 0.002" focus step.
Edit: to add size info for the hobo spider and flowers.
