*According to Merriam-Webster dictionary, troika is a Russian vehicle drawn by three horses abreast. After Lomo 3.7x 0.11 and Zeiss 6.3x 0.16 Semiplan objectives were discovered as fine performing objectives for photomicrography, I have measured their MTF resolution and CA, confirming above average...

Good job, Robert! Those vintage lenses can have all sorts of mechanical problems as you've shown but there are frequent cases of optics related issues as well like delamination or fungus. I am successfully curing both so there are many lenses in my collection bought with "for parts or not working" t...

Very useful comparison, Robert as always. Thank you for that!
And smashing cover photo Who is your designer?
Best regards,
Miljenko

Being occupied with other's lens testing for the last couple of months I neglected my own untested lenses/objectives. New lenses drawer became crowded so it's time to start discovering many promissing items in the following weeks. But besides that drawer, there is another one with scrapped lenses fo...

I'm glad if I could help you to select good lenses for your future macro work, Filip. You'll get full data Excel sheet with your lenses for the future reference. There were some nice discoveries as well as some disappointments, I believe. Now you can concentrate on real macro shooting and I will do ...

Maybe I am misinterpreting the CA numbers, since the normal .3-.8 range on the low end would also match the mitutoyo 5x, but that doesn't seem to be the usual experience with these objectives. With my constant test setup (Fuji X-T2, Capture One and Imatest) my sample of Mitutoyo Plan Apo 5x 0.14 at...

Last two lenses/objectives Filip has sent me for MTF testing are Nikon Plan 10x 0.30 160/0.17 and Reichert aus Austria 10x 0.25 160/-. In order to get the absolute feeling of their performance I decided to test them side by side to currently my only 10x objective, infinite Nikon Plan 10x 0.30 oo/0. ...

So for the short-focused Sigma LSA, the predicted neutral resolution (obtained by simply shrinking the 5x image to 4.5x) would be about 1890. You observed 1987, so yes, this tube lens does improve when short-focused. Thanks for chiming in, Lou. The basic math is clear to me but sometimes real-life ...

Scarodactyl wrote: I wonder if there is much variation copy to copy on these.

Not likely. Large variations are expected with complex lens designs consisting of 10 or 15 elements. Here we have only one compound lens so I expect to see no more than 2 or3% resolution and/or CA sample to sample variations.

Next lens from Filip's collection sent for MTF testing is well known Sigma Life-Size Attachment. A single lens apochromatic „macro filter“ is designed as an attachment you put in front of ordinary (tele) lens in order to do handy close-ups. There are many both contemporary and vintage models on offe...

Are these Zeiss objectives not designed for CA correction in the eyepiece? I had heard that some low-m Zeiss objectives do not need this correction. Lou Zeiss aus Jena objectives from 1968. to 1982. were of achromatic design, requiring mild eyepiece correction for CA but only for magnifications ove...

Next piece of optics from Filip's collection sent for testing on this occasion is Zeiss (from Jena, East Germany factory) 6.3x N.A.0.16 Semiplan. This vintage objective was presented here some time ago by Antonio (Yawns) with very positive impressions. Since all the photos I've seen on the web were ...

Another well prepaired and performed lens review by one and only Robert OToole. I have bought this lens last year supposing it will be nice tube lens when 100mm is needed since some objected my use of hard to find Agfa 4/107 scanner lens. Before getting this incredible Agfa I was using dirt cheap Ni...

Enrico, if you check few posts back, this is exactly the same adapter Cam asked about. And it is part of extension set I recommended (https://www.amazon.co.uk/Fotodiox-Extension-Fujifilm-Mirrorless-Photography/dp/B00D9BL20Y/ref=sr_1_10?keywords=fujifilm+extension+tube&qid=1580927075&s=electronics&sr...

Did you also need to sand down the knurled lip on the front of the lens? My M52-M50 adapter doesn't fit over it and I can reverse thread the adapter on from the other side. Basically, I never touch the lens itself if there is a way to fit by modding adapters. You got it right, both 50-52 adapter ri...