Objective Designations

[geetee50]

Hi i wonder who can put me right. I see on a well know auction site many objectives being sold as Plan with PL as its designation, in my understanding PL was positive low but Pl was plan or Flat Field optical correction, this info is from a Nikon site. http://www.microscopyu.com/articles/opt ... specs.html

I have a Leitz PL FL 10 that i've seen being sold as plan, so is the PL designation for Nikon objectives only or are these being miss sold at auction.

Gary

[Doc.Al]

Hi Gary,

With Olympus phase contrast objectives, the PL designation is for positive low (PL) contrast. There was also PLL (positive low-low), NH (negative high) and NM (negative medium) objectives from Olympus. The Nikon phase contrast objectives are usually marked DL.

With the Leitz older objectives, Pl Fl means Plano (or plan) fluorite, which indicates flat (or plan) field of view with fluorite glass.

So your Pl Fl 10 lens is a Plan lens.

Hope this helps

Alex

[geetee50]

Cheers Alex,

I see at the bottom of my link the Abbreviations: PL FL, Plan Fluorite

So on its own PL is positive low when it is a Phase Contrast lens, but on any other lens it's plan? that makes sense

thanks
Gary

[Pau]

I have a Leitz PL FL 10 that i've seen being sold as plan....

Usually Leitz fluorite (semiapo) objectives are labeled as "Fluotar", not FL, and fluorescence specialized ones as "Fluorescenz". Pl means Plan with a FN up to 28 mm if the lens isn't very old.

Could you provide a picture of the objective showing its writings?

More info at

http://www.photomacrography.net/forum/v ... r+neofluar

[geetee50]

ok thanks.

[Pau]

Yes, it's an old style plan fluorite.

It will be good (or very good) in a Leitz microscope paired with Periplan eyepieces, but because it needs complementary corrections in the eyepieces it would be poor if used alone in a bellows setup

[geetee50]

Thanks Pau, Yes very poor, is there a way of correcting it for bellows use?

[Pau]

In short: no

You would need to place the adequate Leitz Periplan eyepiece inside the bellows at the right position and a relay lens between the eyepiece and the camera, i.e. making a compoud microscope. Possible but not to be recommended,

If you do not own or plan to get a Leitz microscope the best option will be to sell it and to buy an adequate objective like the Nikon CF