Focus stack m3z

[houstontx]

Is it possible to use a leica m3z (CMO) stereoscope to focus stack? Through the phototube? through the eyepiece?

Thanks for your input,

[Olympusman]

I tried stacking wit a stereo microscope some time ago. I found there is to much shift as you focus to get anything to stack.

Mike

[houstontx]

Doesn't a common main objective (CMO) prevent this shift during focusing?

[Pau]

No, in a CMO the light paths for both eyes are still oblique to the optical objective axis, although likely in lesser extent than Greenough.
Some high end stereos have another central path for the photoport, but I don't think that the M3Z is one of them. I've just tested with mine and there is some displacement. That said, stacking could be possible as software can deal with displacements but I never tried it.

[rjlittlefield]

The displacements are annoying but typically not a deal-breaker.

With Zerene Stacker, what happens is that both ends of the image may develop "edge streaks" in the areas that get shifted out of frame at any point in the stack. The central area that is in frame throughout the stack will be rendered clearly.

It is best if the camera optics are set up so that the frame is entirely occupied by subject, with no vignetting even in the corners. Otherwise the alignment method may lock onto the vignette instead of tracking the subject. This problem can often be worked around by specifying an on-the-fly crop that removes the vignette, using Options > Preprocessing > Image Pre-cropping.

If the displacements are unusually large, you may also want to increase the limits for Shift X and Shift Y, at Options > Preferences > Alignment.

--Rik

[JohnyM]

Not sure if that helps, but in my experience, no stereoscope can produce better image (stacked or not) than Mp-E65, which is also cheaper than any scope. Only con i've found is that Mp-E65 is not parafocal when zooming.

[houstontx]

Thanks for the replies. Eventually I will move to a focus stacking rig. I have a 105mm Micro-Nikkor I use occasionally but I don't have a rail setup yet. For the pictures I take a stereo zoom works for now. And you can't beat the ease of use. I was hoping to try a few stacks with a phototube from an M5A non CMO, but not sure if it is compatible with the M3Z.

[Pau]

an M5A non CMO

If you refer to the Leica/Wild M5A it is CMO, I have it (Apo version, but it's the same). Its phototube is not compatible at all with other models (except the Motic K series chinese clones)

[houstontx]

Interesting thanks Pau! I'll try some stacks this week.