hmm - that’s odd, I must admit I’m not sure if I’ve ever used the infinity corrected version in anger, it was added in response to some people who requested it. I designed it for the same parfocal distance as the regular objectives (45mm from shoulder to sample if you use the 10mm riser). Is the problem that your objective is taller than that?
It’s easy enough to render a taller illumination dovetail, though it’s not in the standard automatic build. Do you know the parfocal distance of your objective?
After some test the sample rise need to be 20mm if you fix the optic on the max upper side of Z, and by the way, the key passthought for the optic screw is to low and not that helpfull in this position…
If you have an infinity corrected lens and use with a finite back focal distance the working distance to the sample will increase (if you think of it as a simple lens). The image quality will also degrade, probably much more than you might think.
Just thinking a little more. The parfocal length is 45mm: when you construct the microscope with the parts you have, what is the distance from the objective mount to the sample stage? If it is less than 45mm, that may be why you need the sample higher. If it is 45mm, the problem is in the optical part: the focal length of the tube lens and distance from tube lens to camera. Have you checked the tube lens is f=50mm? The simplest way is to focus the image of a window or lamp on the other side of the room onto a piece of paper and measure the distance from lens to paper. It will be slightly more an 50mm for a f=50mm lens, and does not need to be very precise: you are only checking that it is not f=25 or 40 or 70 by mistake (a mistake I often make)
Ah I see - probably the best solution is to make a taller version of the microscope stand. If you are able to clone the repository and build the STL yourself from the OpenSCAD file (either using the build script or just the OpenSCAD program), then it should be fairly easy to make a taller version of the base (I think the height is set at 30mm by default, so you can just dial up the extra height you need).
That is a really nice image @Gris74 . The 45mm is measured with the metal and blue risers in place and you cannot move the lens down because of the pi base below? Modifying the parameter in OpenSCAD as @r.w.bowman suggests would give you the neat microscope, but OpenSCAD needs a little learning. Could you instead put the metal stand-offs between the microscope and the base to give you the extra room? Or house the pi beside the microscope instead so that the lens can go down into the pi base?
Not in this configuration with my metalic rise, but from the official release 6.0.0 the infinity corrected lens is pushing the Raspberry cam connector.
Thanks for your tips about moving my metalic rise between microscope and the base, i will give a try.
Anyway I need to do some mesurement for the exact rise value for this infinity corrected lens and will share here, and I will go for some hours of OpenScad learning I dont see other alternative.
I’ve made you a taller version of the stand, as it wasn’t a big change (it’s always easier to tweak things when you know where to look already If you’re curious, the tweak to the code is here:
As I don’t have an infinity corrected microscope to test it with, I would be grateful if you could confirm this works. If it does, I’ll get it included in the standard build and instructions. In case it saves you a print, I’ve made it 15mm taller. If that sounds like too much or not enough, just shout and I can easily tweak that. Looking at your photo, I suspect I’d have gotten away with 10mm, but the extra 5mm won’t take long to print, and improves your chances of getting it to work first time!