Vixen 90M

[N1]

Hi achro buffs, I've just become the (proud? see attached view though OTA :eyepop:) owner of an old, tired & dirty f/11 Vixen Custom 90M. No matter, it wasn't expensive. Anyway there is dirt on all surfaces, including between the lenses and they really could use a clean. I seem to have figured out how to get them out, but the question is whether there is any way to ensure they go back in half-way collimated (the cell isn't collimatable), other than by marking their orientation? :thanx:

[Terry B]

Looks like a moth. :P

[Wilso]

Looks like its metamorphosis stages all caught on camera :D
Sorry

[anj026]

Collimation should be fine if you put it back the same as original. Should be a really nice lens. The longer the focal length the more forgiving the collimation is and it is easy to check with a Cheshire eyepiece. I have a really good Vixen spec Antares 90/1500 lens. It is outstanding for an achromatic lens.

[Wavytone]

During disassembly put pencil marks on the edges of the elements so you can put them back in the same orientation. The rotation of the elements with respect to each other is important and should be maintained in reassembly.

It also a good idea to put marks on the OTA and lens cell so these parts and the lens elements are all in the original (rotational) alignment. For black metallic parts a kids crayon will be more visible than pencil.

Use something you can remove later on the OTA.

[N1]

Thanks guys, lenses removed, marks applied. Looks like the coating has suffered between the elements also. Let's see how it turns out after cleaning. :thanx: