Checking an FSU lens with MTF tester

I think when I comes to FSU lenses the results will fall all over the map. A lot of times when people mention FSU lenses a small disclaimer will follow "if you get a good sample". They can be very good but some can also be under performing to their reputation. It all depends if the tester gets a good sample.
 
MTF tester? There may be industrial devices capable of capturing and analyzing the image at the film plane, but a full-frame digital camera would be essentially the same thing. The techniques used with digital cameras can also be applied to scanned film, though as with digital cameras you are testing the entire system (lens, camera, film, and scanner) rather than the lens alone.

If you are simply interested in evaluating a lens you have recently purchased, the proof of the pudding is in the eating. A careful tripod-mounted shot of the classified ads of the local newspaper at 20x the focal length distance (or minimum focus distance for wide angles) will show the weak points of most lenses as well as detect centering and other defects.

Steve
 
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ItsReallyDarren said:
I think when I comes to FSU lenses the results will fall all over the map. A lot of times when people mention FSU lenses a small disclaimer will follow "if you get a good sample". They can be very good but some can also be under performing to their reputation. It all depends if the tester gets a good sample.
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Unfortunately, this is not just an issue with FSU lenses. A quick look at the lens reviews of new product at photozone.de and other such sites will reveal multiple instances where centering or other defects are present.

I guess I will have to count myself as lucky. I have purchased eleven FSU lenses over the last couple of years (two in K-mount, two M42, four in Contax-Kiev, and three in LTM). Of the eleven, three were bad and the others are very good to excellent performers. Of the three bad ones, the first was a new in box Zenitar 16/2.8 that appeared to have been dropped at the factory (simply broken), the second was a Jupiter-8M from 1960 with a broken aperture blade, and the other was a Industar-61 that looked to have been assembled from a mix of different lenses of various vintages (i.e. not a factory lens).

Now the matter of "under-performing to reputation" is an interesting concept. What I have finally decided is that certain lenses gain a reputation through the magic of the Internet. One person raves about a particular lens and the rave is quoted widely and reinforced by testimonial from other owners. In a matter of a few weeks you have a cult classic. This is followed by a buying frenzy and inflated prices followed shortly after by the posts of many disappointed new owners who were expecting miracle glass. Despite the disparaging posts, the cult reputation survives, but is tempered by the "if you get a good copy" note.


Steve
 
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stevebrot said:
Now the matter of "under-performing to reputation" is an interesting concept. What I have finally decided is that certain lenses gain a reputation through the magic of the Internet. One person raves about a particular lens and the rave is quoted widely and reinforced by testimonial from other owners. In a matter of a few weeks you have a cult classic. This is followed by a buying frenzy and inflated prices followed shortly after by the posts of many disappointed new owners who were expecting miracle glass. Despite the disparaging posts, the cult reputation survives, but is tempered by the "if you get a good copy" note.


Steve
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The same applies to sellers of fsu cameras etc. How often have you read a comment like 'I haven't used so and so myself, but I they have a very good reputation'. Reputations become magnified so that when someone has a negative experience they often tend to keep quiet.
 
Worse still, forums encourage people to attempt their own repairs and don't mention things like the tools needed, what to do when things go wrong and so on.

So lenses appear that have elements in the wrong way round, missing screws and so on. I've one in the collection that performs well but has had all the linkages inside and the aperture blades removed. Luckily it's for a SLR and so can be used wide open all the time on the "A" priority but...

Regards, David

PS Steve; how did you know your one was dropped at the factory? There's usually more clowns in the audience than in the circus ring...
 
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I have seen a lot of sample deviation in Jupiter-3's, with the best ones being among the oldest ones. The worst ones were "New-Old-Stock" J-3's from the 1980. Three of the 1980s samples bought new, I parted out to replace bad front elements in older lenses.

The best ones: 1950s KMZ samples are as good as wartime Sonnars.

I prefer testing a lens on the camera. If the lens in question produces color-aliasing on the M8 when used wide-open, I know it is a sharp one. Otherwise, the ZK-Sonnar is a nice matched-optic for the M8 when used wide-open.

http://www.rangefinderforum.com/forums/showthread.php?t=85011

My two 1953 KMZ J-3's are slightly sharper than the ZK Sonnar doing this same test.
 
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David Hughes said:
PS Steve; how did you know your one was dropped at the factory? There's usually more clowns in the audience than in the circus ring...
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The lens was procured new through rugift.com, was purchased by my new "friend" in Moscow and shipped directly to me in the factory box. All the packaging was in good order and had no indication of tampering or having been opened prior to receipt by me. My big mistake was in mounting the lens before thoroughly checking everything. After mounting the lens I found that the focus ring would not turn lock-to-lock, but bound halfway through its travel. The aperture mechanism was totally non-functional.

I did not know how non-functional it was until I took it off the camera and discovered that the coupling levers (it was K-mount) were hopelessly out of alignment and had severely damaged the mirror box mechanisms of my treasured Ricoh XR7 during the mount. I don't know for sure that it was dropped, but I cannot imagine what other misfortune might have attended it that would have resulted in such extensive damage. The replacement lens from rugift was in much better shape and only required adjustment to infinity focus to put it in good order.

Sad story, eh?

Steve

(You may wonder why the attachment to the Ricoh. It was my primary camera for about 25 years and was carried on many adventures. It performed many thousands of exposures without a single malfunction and was a trusted tool.)
 
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"Sad story, eh?"

Yes, it is sad and I'm sorry to learn of your problems.

I asked because I am continually reading complaints about the lenses that are blamed on the makers when the lenses must be 50 or so years old and are obviously second-hand. Worse still, a lot of people try to repair them themselves and make matters worse by then selling on their mistakes.

My experience of the ex USSR lenses is that they are OK with one exceptiuon (stiff aperture control) and that is understandable considering the age of the lens. I've had worse problems with Leicas and one of Contax's cameras.

Regards, David
 
It is typically easy to determine of a lens had it's shim changed after leaving the factory- you have to move the aperture ring to line up with the index. That requires new taps for the set screws. It is also easy to determine of the helical is repositioned in the mount- new taps for the focus ring.

I've seen several lenses that were way off, the focus ring and aperture ring lined up correctly with the marks, and there were no additional taps. The lens left the factory the way it was found.

I have a 1953 KMZ lens with two sets of identical taps for the focus ring and two red dots for the aperture index. Had to have been done at the factory, or at least on identical equipment. Taps using a drill are just not as nice, not as well formed as those from the factory. They should have left the helical in the first position, which was correct on my camera.
 
Thanks Brian, dare I ask what your experience is with lenses and bodies that have been messed around with by their owners?

My experience in other fields is there are a lot of ham fisted people about who don't consider having the right tools necessary and who charge in like the proverbial bull in a china shop. They're the ones who wonder why doors have signs on them saying "Danger Keep Out" and then stroll in.

And my experience of cameras and lenses is that they all can give trouble and there's few ways of knowing who to blame. The ex-USSR ones are cheap and I think people see it as OK to play with repairing them, but not (say) an elderly Leica or Contax.

Regards, David
 
I have seen a Jupiter-3 with the wrong optics in the rear section, which could not form an image. Either custom made for some piece of imaging system (a real possibility) or someone just kludging parts together for an Ebay sale. On that lens: I ended up moving glass to another fixture with a later rear group and the outcome was one of the best J-3's I've ever seen.

The worst from the factory: A 1950 Jupiter-3 that the optics fixture was too long and the lens had a focal length that was way-way off. Could not hold focus with the RF across any reasonable range. It was probably more assembly practice than useful lens. I tried polishing down the fixture to move the rear group in where it should have been but no luck. The Fixture used appeared to be a pre-war, brass mount. Interesting, but i wanted a lens that would work. i parted out the glass to repair two Sonnars,
 
Interesting: I've had similar on a Summar and an Elmar (both 5cm). The Elmar was sorted out by Malcolm Taylor and bits supplied and the Summar was written off at enormous expense.

Just been looking at my catalogue/records. I've had 12 ex-USSR bodies and 15 ex-USSR lenses. Just one lens problem (mentioned). The oldest body being from 1950 and the oldest lens with a Cyrillic letter "P" on it to show it was from the coated stuff; perhaps 1946? I ignored one I bought thta had been used as a parts donor as I was curious to see inside without doing any damage.

The only problem with ex-USSR stuff is the little things like lens caps and hoods (but no worse than Leica) and, of course, the leather cases that usually need restitching. Luckily I was taught sewing and ironing in the Army and we still have old fashioned cobblers around in this part of the world.

Regards, David
 
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