Delta microscope RMS optics

Looking through optics.scad, there are rms_f50d13 and rms_infinity_f50d13 options that set different parameters, and in the comments:

“tube_length is the distance behind the objective’s “shoulder” where the image is formed. This should be infinity (safe to use 9999) for infinity-corrected lenses, or 150 for 160mm tube length objectives (the image is formed ~10mm from the end of the tube).”

The provided transmission illumination optics module appears to be the finite-conjugate variety only, and the build script seems to confirm this. Even the reflection version has the short path length.

When configuring the cartesian version of the microscope, selecting the infinity optics version requires a taller base due to the longer optics module. Looking at the delta and cartesian optics modules side by side the delta one is clearly shorter, even though the optics path should essentially be the same. Is this how it’s supposed to be?

Optically the Delta and cartesian Microscope will be the same. There is a mechanical difference in the orientation of the camera and the mounting rail. It does seem that the Delta only gives the 160mm version. @samuelmcdermott may be able to shed more light on that.

For my build, I printed the 160mm version and used an infinity-corrected objective and it worked fine. I also made some modifications to the code and printed a delta version of the infinity optics,

and that works fine too.

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Yes, the Delta Stage only officially supports the 160mm objectives, as they’re the most commonly cheap ones and the only ones I can test at the moment.

The code should be ready there in the optics.scad to support the infinity corrected objectives (as you’ve discovered), so if people have tested it and it fits in the microscope and base then it can be included in the build system.

If you could, it would be useful to raise an issue, with your results. Thanks!

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