WTB: Zeiss C-Apochromat 63x/1.20 W Corr

[tpruuden]

Maybe there is someone wanting to part with one. I would like to see the green laser transmission projection to evaluate the condition before buy.

Thank you!

[ImperatorRex]

FYI: It is offered on ebay here:
https://www.ebay.de/itm/295471899950?ha ... R4r52Zy2YQ

[tpruuden]

Thank you, this is bit high priced there.

[abednego1995]

I have a C-Apo UV-VIS-IR 40x NA1.20 W Korr. in the older RMS mount if you might be interested. What do you mean by green laser projection?

[tpruuden]

Slightly expanded laser shows well common faults like damage to front lens. Ideally the projected image is homogeneous circle (assuming laser beam is clean), free from aberrations from damage or dirt. Not an ideal or exhaustive test but quick and simple. On the image the beam expander (laser source optics) is slightly dirty, so there are some variations in brightness.

I would like to find the M27 version of 63x.

[abednego1995]

I see, thank you. That method is interesting. Would you suggest using the laser despeckled? or is the beam sufficient as it is?

[PeteM]

Tom, that (green laser projection) seems a clever idea. On trying it, turns out my own green laser pointer had all sorts of defects with a known good (careful inspection with phase telescope) plan apo objective. The defects rotated with the laser, not the objective. It was clearly a dirty, defective, or just a too-cheap laser.

Any suggestions for a moderately priced laser that provides a nice even image when projected?

[tpruuden]

Spatial filtering would make it clear - pinhole in foil will give good clean spherical wavefront (needle used on aluminium foil resting on ceramic tile gives quite good small pinholes). It may be, that diode laser without optics is actually better for this kind of evaluation but I have not tried it.

[PeteM]

Thanks.

[stitchy.mitch]

This is really clever.