dexdog
Veteran
Close focus at about 1.25 meters at f3.5, North American columbine (Aquilegia canadensis) thinking about flowering soon.
The critter table near my front door. Point of focus is nose of the turtle, about 1.5 meters at f3.5
Looks like a good lens.
The critter table near my front door. Point of focus is nose of the turtle, about 1.5 meters at f3.5
Looks like a good lens.
dexdog
Veteran
I took apart two CZJ 5cm f3.5 Tessars to look at the shape of the front lens group, a 301 series from Jan 1947 and 310 series from Oct 1948. The attached pics are from the 310 series lens, but the 301 series lens was identical. The 310 series lens is often called the "black line Tessar". The shape of the lens group is different that the KOMZ lens in post #200, above. I have no idea if the KOMZ lens has Schott glass, but the front lens group is different from CZJ Tessar production of late 1940s
Partial CZJ serial on fixture
Partial CZJ serial on fixture
TenEleven
Well-known
How do you like the 3 million series Tessars?
They have a reputation for being not very good in Japan - and to be honest I have not had much luck with them either (bought from overseas). At least they are priced accordingly and I did not lose much.
They have a reputation for being not very good in Japan - and to be honest I have not had much luck with them either (bought from overseas). At least they are priced accordingly and I did not lose much.
dexdog
Veteran
TenEleven, to tell the truth, I have not used them all that much. I find it difficult to pick up a Tessar when I have a number of Sonnars to choose from!
TenEleven
Well-known
I find they do make slightly better landscape lenses (on film) but similarly to you I rarely use them regardless. I guess one can always give up on f1.5 and use a good copy of a f2 Sonnar and stop down to f8 or thereabouts - voila edge to edge sharpness, also.
MarkWalberg
Established
Any info on this unusual 1955 KMZ Jupiter 3?
A Jupiter 3 on eBay
It is said to have a flange distance of only about 25.5 mm.
What was it for?
I won't be paying that much for any lens, but it looks interesting.
A Jupiter 3 on eBay
It is said to have a flange distance of only about 25.5 mm.
What was it for?
I won't be paying that much for any lens, but it looks interesting.
These used to go for cheap. Same flange distance as a regular J-3.
It's basically a simplified focus mount, an enlarged J-8 mount. Not as good as the regular mount. It was basically a failure. So failures are rare, and someone wants a lot of money for it for just that reason. Edsels are also rare, I'd rather have a '66 Mustang.
TenEleven
Well-known
Yeah if he says the flange is too short - by 3mm almost! Then this lens has been screwed with already in some fashion. It should have the same register distance that all leica (and Russian) stuff should have - 28.8mm. Leitz specify the tolerance for the correct flange distance as +0.015mm / -0.005mm IIRC. So you can see how far off from usable this lens is.
Anyway, where the Russian lenses differ is that their standard focal length is 52.4mm versus 51.6mm Leitz standard. This means a well calibrated (not all are) Russian lens should be fine at infinity and then increasingly lose focus as you get closer. The focus will be increasingly to the back of your subject, and this is exactly what a good copy will do.
This focal length, by the way, is not just a feature of Russian lenses. Heck even Leitz lenses have it - they used to engrave the FL actual on the barrel for early Leica lenses.
I have a Canon 50/1.8 LTM version II, which of course was intended for use on Canon or Leica rangefinders following Leitz' standard. However the lens focal length is slightly too short. Canon "solved" this by making the shim (flange distance) a fraction of a millimeter smaller than it should be; thus compensating for front-focus as your subject gets closer. This means at infinity, or far distances, the lens overshoots a little bit and gets better as you focus closer. On film this "hack" is not noticeable. Even in film tests at full aperture I never saw an issue, because focus on film is "squishy". It did throw me for a loop when I put it on my (28.8mm calibrated) digital camera, though!
Anyway, where the Russian lenses differ is that their standard focal length is 52.4mm versus 51.6mm Leitz standard. This means a well calibrated (not all are) Russian lens should be fine at infinity and then increasingly lose focus as you get closer. The focus will be increasingly to the back of your subject, and this is exactly what a good copy will do.
This focal length, by the way, is not just a feature of Russian lenses. Heck even Leitz lenses have it - they used to engrave the FL actual on the barrel for early Leica lenses.
I have a Canon 50/1.8 LTM version II, which of course was intended for use on Canon or Leica rangefinders following Leitz' standard. However the lens focal length is slightly too short. Canon "solved" this by making the shim (flange distance) a fraction of a millimeter smaller than it should be; thus compensating for front-focus as your subject gets closer. This means at infinity, or far distances, the lens overshoots a little bit and gets better as you focus closer. On film this "hack" is not noticeable. Even in film tests at full aperture I never saw an issue, because focus on film is "squishy". It did throw me for a loop when I put it on my (28.8mm calibrated) digital camera, though!
The Summarit is also marked internally, and the Five I took apart are 51.1mm The lens is set to focus at Infinity at F1.5, and front focuses about 1" at 3ft. Stop down F2~F2.8, focus shift gives perfect focus. After all "Who would use a lens close-up and wide-open?". ..
TenEleven
Well-known
Also front focus is, of course, the more benign problem to have.
I am sure if the Contax standard had been 50.8mm (0.8mm discrepancy but the other way) there would have been a lot less complaints about Russian lenses being "bad" - at least until digital rangefinders came along.
I am sure if the Contax standard had been 50.8mm (0.8mm discrepancy but the other way) there would have been a lot less complaints about Russian lenses being "bad" - at least until digital rangefinders came along.