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Question on Leitz objectives
Posted: Sat Oct 19, 2019 11:44 am
by geo_man
Hi all. I purchased this 2.5x lens to add to my Leitz Dialuz POL to provide a wider field of view for scanning my slides. My current 4 Leitz Wetzlar Objectives are: 3.5/0.10 P 170/- --- 10/0.25 P 170/- --- 25/0.50 170/0.17 --- 50/0.85 P 170/0.17
Unfortunately the new 2.5x is very non parafocal with a much longer working distance. How do I determine which (if any) 2.5x objective would be approximately parafocal with my other objectives? Thanks in advance for any advice.
Re: Question on Leitz objectives
Posted: Mon Oct 21, 2019 8:10 am
by luxikon
Hi,
if you google for:
LEITZ Image-forming and Illuminating Systems_engl.pdf
you'll find a brochure with all the information you need
esp. adjustment length of all Leitz objectives.
In case you are German speaking search for:
LEITZ Abbildende und beleuchtende Optik_1973.pdf
Klaus
Re: Question on Leitz objectives
Posted: Mon Oct 21, 2019 9:43 am
by geo_man
Thank you, luxikon. That is quite a document! I'll give it a look.
Re: Question on Leitz objectives
Posted: Mon Oct 21, 2019 10:21 am
by jimur
Would a plezy not decrease the working distance for the 2.5x?
Re: Question on Leitz objectives
Posted: Mon Oct 21, 2019 12:40 pm
by apochronaut
I am not sure about objectives in the Leitz 170mm D.I.N. system but it is not uncommon for very low power objectives to have a very long working distance and be not parfocal with the higher power objectives.
In certain instances, manufacturers offered two options; a standard l.w.d. option and a parfocal option, where the objective was in fact an undercorrected 5X with an extension that carried a reducing, overcorrecting lens at it's tip. The extension , brought the overall magnification down, the planarity and peripheral corrections up and the length of the objective to equal that of the rest of those that it was designed to be used with, for perfect parfocality albeit a limited w.d. The N.A. of the two versions was the same in the examples I am familiar with.
Re: Question on Leitz objectives
Posted: Mon Oct 21, 2019 1:11 pm
by geo_man
Thanks all. I decided to return the 2.5x objective. I had the second problem that one of the centering screws on my unused opening seemed to be stripped so I couldn't properly center it. No big deal as I still have 4 good properly centered objectives with a good range.
I also purchased lower power / wider field eyepieces so I expect to improve my overall FOV as desired (I had 12.5x periplans, I bought 10x periplan GFs). Should receive them today. I have a 1.25x tube lens system.
Thanks again!