PLANAPO eyepieces

[microscopeboi]

hey, ive recently purchased a nikon planapo 20x objective, are there special eyepieces i should buy with it? thanks

[Scarodactyl]

It depends on the era. Nikon was ahead of the curve--in the labophot era they introduced the "CF" series objectives, with all corrections done internally, requiring no eyepiece corrections. This carried over to their infinity-corrected CFI series.
If you have an older one it will need eyepiece corrections.
I'm going to bet though that you got a 20x/0.75 planapo N DIC objective for like 100 bucks on eBay, right? These require no special corrections. You can put them on any high-quality 200mm lens and put the image directly onto your camera sensor if you want.

[microscopeboi]

It depends on the era. Nikon was ahead of the curve--in the labophot era they introduced the "CF" series objectives, with all corrections done internally, requiring no eyepiece corrections. This carried over to their infinity-corrected CFI series.
If you have an older one it will need eyepiece corrections.
I'm going to bet though that you got a 20x/0.75 planapo N DIC objective for like 100 bucks on eBay, right? These require no special corrections. You can put them on any high-quality 200mm lens and put the image directly onto your camera sensor if you want.

yeah i did, why are they so cheap? it seems like they should be closer to 300-500. and thanks!

[Scarodactyl]

They came out of an obsolete gene sequencer. They should definitely be much, much more expensive, but the supply is pretty high right now. They're the best deal in optics right now--perfect color correction, high resolution, strain free, just nice.
Just make sure you're using it on an infinity-corrected scope with a non-compensating tube lens in the head. If it doesn't have a lens to refocus the light you won't get a good image.

[microscopeboi]

I have an infinity corrected scope, how would i know if i have a non compensating tube lens?

[Scarodactyl]

It varies from brand to brand. I think that Chinese ones tend to be non-compensating. Olympus and nikon are noncompensating, zeissx leica, ao/reichert are comlensating. Not sure about Meiji.

[microscopeboi]

okay, if i have a non compensating tube lens does this mean that i shouldnt get objectives from zeiss? i was reading up on it and i read that zeiss typically have lenses that help with infinity correction in the tube

[Scarodactyl]

Yeah, zeiss infinity optics won't give the best results on a non-zeiss head, same with Leica objectives. It may not be that big an effect but a high end Leica or Zeiss objective is likely to be so expensive that you could get a better matching objective for cheaper.
Nikon an Olympus aren't 100% compatible just because both have internal corrections though--they have different parfocal lengths and different focal lengths in the tube lens, so olympus objectives will give extra mag on a nikon head. and nikon objectives will give lower on an olynpus head. They also have different threads. Your nikon has an m25x0.75 thread vs rms for a modern olympus.