Eugene said:
Eduard, sample variation indeed is present, but by the factory specs H-103 has noticeably higher resolution. For a fair comparision a test at maximum apertures is a must, and of the two (different age, but none really early tho) J-8 samples I tried noone came close to the Helios. From f/4 and above there really isn't that much difference. But there's no warranty that you wouldn't get a dud of course.
I didn't say H103 gives blurry image and J8 is razor sharp. What I said J8 could be reasonable sharp, sometimes even better than H103. If saying "factory specs" you mean technical requirements which is also known as TU (in cyrillic TY-blah-blah-YY; blah-blah is a number encoding item and YY is a year these TU were released), I'm very aware of TU. When I was young I maintained a massive chart of soviet lens specs in my notebook, mostly picking up information from publications in "Sovetskoe Foto" magazine. I did that for very simple reason - I didn't want to buy a lens which has poor technical characteristics. Once I was asked why I didn't consider buying Jupiters and I replied that reason is their poor resolution. Then a couple of passports for Jupiter lenses were produced to me. Passport, as you know, is a small paper stating number of lens, which TU it meets, when it was manufactured/sold, stamp OTK (OTK means QA) and sometimes measured resolution during factory tests. These two had hand written resolution in lpm center/edge. I didn't touch my notebook since and I don't know if my mom still keep it in a pile of junk I left. Should I say those Jupiters had better measured resolution than my considered sharp lenses (also measured data from passports). I know that many Jupiters were as bad as advertised in TU, and I believe I know how that man got those exceptional lenses... you know, normally you can't check 10 or 20 passports to pick up the best, but sometimes it was possible.
Returning to original question that was asked I still think the best approach is to test. Mauro already has two lenses, so there is no problem to test them.
I'm sorry to hear you had two bad J8 samples. Keep looking and you'll find one. Mine is J8M, from 1979...
On related note, I was looking for J9 this summer. I tested 3 different lenses:
1) Good, usual J9 as one can dream. Very narrow DOF at f/2 but definetely sharp. Slightly low contrast which could be strong point for portrait lens.
2) Good, but something unusual in drawing. At glance it seems more sharp than #1, but looking closer it's not sharper but contrast is unusually high for J9. And picture has some 3D look... I spent couple of hours looking and comparing boring test pics and decided this lens gives some tonal perspective, that's why image doesn't look as flat as with #1.
3) Soap. There was no DOF up to f/4 because there was no focus point - everything was blurry. At f/4 it was close to #1 and #2 at f/2 and at f/8 one could think this is quite acceptable lens if didn't see first two.
They all met once the same TU, they all were manufactured just 1 year apart, but soooo different. I bought #2 though it was not best lens mechanically from samples the seller provided.
Attachments: J8M, ProFoto 100, f/2 1/1000. Original negative (yes I have problems with framing
🙂 ), rotated and cropped pic, 100% pic fragment scanned @3200 dpi if we talk about sharpnes. You can see narrow DOF, poppy flower is sharp everything else blury.
Eduard.