Leica Infinite Objective Lens with Iris on E-Bay

abpho · Post by **abpho** » Tue Feb 21, 2017 9:52 pm

Has anyone ever seen or used these Leica infinite macro lenses with an iris and the crazy HUGE working distances? Maybe these are of interest to someone here.

Link here for the 3x. Or a link here for a search of "leica iris macro objective RMS". A 4x was up earlier as along with the 0.66x, 1x, 1.5x, 2x, 2.5x, and 3x.

rjlittlefield · Post by **rjlittlefield** » Tue Feb 21, 2017 11:45 pm

I have no prior knowledge of these lenses. I notice that all the different magnifications that I checked say "working distance 60 mm", despite that the objectives themselves appear to be slightly different lengths. I wonder if they're actually 60 mm parfocal distance, measured from the shoulder of the mounting threads, like Nikon CFI60. I also notice that the photo of the 3X objective shows "3X/0.75", while the ad says (much more plausibly) "3x 3/0.075". Either the "0.75" is a mistake in the labeling, or it's designating something other than NA. Seems odd either way, for a lens carrying the Leica logo.

By the way, with a designation of inf/0, these things look like metallurgical objectives, designed for use with a tube lens, not in any sense traditional macro lenses.

--Rik

ChrisR · Post by **ChrisR** » Wed Feb 22, 2017 4:19 am

If you search for Leica UFM4 -
"Forensic Microscope" - plenty of hits.
Handy for comparing bullets.
I found that delving into the documentation for some unfamiliar (to me) microscopes, the numbers on the objectives were misleading to me because of the way the microscopes work.
"3x/0.75" does look odd, though.

abpho · Post by **abpho** » Fri Mar 10, 2017 1:36 pm

I bit the bullet and picked up the 4x. Magnification is around 4.3x with a 200mm tube lens. Corners seem to be soft on a full frame sensor. To get a better sense on it's performance I will need to do a test stack, one of these days. And comparing it to the MP-E at the same magnification.

Would you suggest I shot the MP-E stopped down to keep the lighting levels the same between the lenses? That works out to be around f/6.3. Or should I shoot the MP-E at f/4 where it is at it's optically optimum?

Cheer!S

ray_parkhurst · Post by **ray_parkhurst** » Fri Mar 10, 2017 4:30 pm

I missed this thread first time around...

These objectives were developed for, and sold with, the "Leica Video Microscope". This microscope was based on an obscure B&L stand for the MonoZoom-7 system. The Video Microscope used the upright column from the MonoZoom-7 stand and added a Leica XYZ stage. The Tube Lens was incorporated into a case that fit the MonoZoom-7 mount, and was fitted with a 4-position turret. The system was designed for C-mount cameras, so coverage is not great, even on APS-C. I have worked with a few of these systems in the past several years, mostly modifying the excellent stands for use as vertical coin photography systems. I sold most of the tube lenses and objectives, though I still have a full "stock" set of 2x, 2.5x, and 3x. Every system I've worked with. I think the 0.6x, 1x, and 4x were options.

edited to correct memory error...I looked at the stock set of objectives and they are actually: 1.5x 2x 3x

abpho · Post by **abpho** » Sat Mar 11, 2017 10:10 am

Thanks Ray. I'll still do my test one day. If it fails to cover an APS-C sensor it might be a great lens for a micro 4/3 camera.