Refurbishing a microscope

[microb]

So I have some microscopes to fix up. What would be the be the best approach here? The optics path was cleaned. The cracked heat window was replaced with a close match tested with a spectrometer. I haven't cleaned the objectives at all. But I think the main problem are with the light source, a tilt to the table that makes focus across the image hard, and chromatic with the images.

ISSUES:
The mercury lamps are very yellow. I'm assuming that that means the bulbs are close to end-of-life.

I had to add a diffuser to even out the lighting.

The images here are from a Leica DMIL 160mm objectives.

The calibration target shoes a tilt issue for focus, and a color separation.

[microb]

So I can remove the diffuser by just drastically moving the condenser to far away, getting the lamp background more in focus, or closer till it hits a mechanical limit about 55mm away, which is what the lens is labeled S55. The light source blurs better there. But the strong chromatic aberrations are still there more towards the top of the image.

[microb]

For the Leica DM IL, what camera set up for a smaller sensor on the c-mount should be used?

If I hold a card above the c-mount (no camera), I see my calibration slide's "=0.01mm" text. But with the camera there, it's heavily cropped.

[Hobbyst46]

Unfiltered light from a mercury lamp is bluish-white, not yellow, even near the end of life (AFAIK).

[microb]

Unfiltered light from a mercury lamp is bluish-white, not yellow, even near the end of life (AFAIK).

Checking the manual...

Ok. So I guess this is a Halogen bulb not Mercury. But I didn't think they went yellow either:

[microb]

So if I add in a blue filter to the lamp, the color evens out more.

Still image-wise, it is highly cropped with chromatic distortions and there's dirt somewhere.

[microb]

Adding ND filter, upping the lamp, and then setting white balance:

[hans]

Yeah, that transverse chromatic aberration looks familiar. I am not familiar with Leica DM but I think I remember reading some posts here that the early Leica stuff was derived from the AO/Reichert 45 mm parfocal infinity system? Are you sure about the 160 mm tube length? I saw in your other thread about the camera, it looks like you have a trinocular head and some Leitz eyepieces? Do you see similar transverse CA through the eyepieces?

[microb]

Yeah, that transverse chromatic aberration looks familiar. I am not familiar with Leica DM but I think I remember reading some posts here that the early Leica stuff was derived from the AO/Reichert 45 mm parfocal infinity system? Are you sure about the 160 mm tube length? I saw in your other thread about the camera, it looks like you have a trinocular head and some Leitz eyepieces? Do you see similar transverse CA through the eyepieces?

I think the 160 is correct. There is no lens in the trinocular. Everyone sells these with 160 objectives. The Leitz trinocular someone here said was used on a 160 microscope model. So I think the 160 set-up is confirmed.

I have one Leitz APO objective, the rest are Leica 160 and Leica 160 PHACO's. The Leitz is a 170/0.17 PL APO 16/0.40. I can retry the Leitz, but I think it had the same issue.

This is a DM IL done when Leitz and Leica merged. The latter models switched to using a Leica head and the right prism with doublet located in the corner of the frame below the objective turret were replaced with a penta prism, no lens. So that's when they went to infinity and beyond but using the same frame cast.