Jupiter 8 Lens Fuzzy...Why?

[sooner]

Hi Folks,

I got a test roll developed with my new Zorki 4k and Jupiter 8. Unfortunately, the Jupiter shots are all blurry, consistently, as opposed to say part of it being in focus albeit not the part I intended. What does it mean if the entire frame is blurry? Did I screw it in wrong, or is it the lens? Any guidance would be appreciated. Thanks. --John

PS Ignore my earlier post about the Zorki 4k messing up, I just sort of tweaked a couple gears in there and the shutter cocked again and seems okay now.

 

[Duncan Ross]

Hi Folks,

I got a test roll developed with my new Zorki 4k and Jupiter 8. Unfortunately, the Jupiter shots are all blurry, consistently, as opposed to say part of it being in focus albeit not the part I intended. What does it mean if the entire frame is blurry? Did I screw it in wrong, or is it the lens? Any guidance would be appreciated. Thanks. --John

PS Ignore my earlier post about the Zorki 4k messing up, I just sort of tweaked a couple gears in there and the shutter cocked again and seems okay now.

Can you try comparing the distance on the lens scale with the actual distance between the back of the camera and the subject in focus, maybe the rangefinder is out by a lot.

Soviet optics seem infamous for variance but the Jupiter 8 is pretty hard to get that wrong, is there any sign of amateur disassembly on it?

 

[sooner]

Thanks for the analysis. I don't think the lens has been worked on, but I really don't know and can't tell for sure. So, Dave, is there anything I can do other than chuck this lens in the trash and buy a new/used one?

The distressing thing is that this lens came on a Zorki 4k that never worked right, sold to me by a fellow RFFer. Hmm.

 

[photodog]

The Soviet lenses are pretty much hit and miss. You could get lucky. My luck has been 50/50. I bought a Zorki with a black J8 and the lens was soft wide open at infinity. Image quality at f/4 was much better. Another J12 I got was not sharp at infinity but I fixed it by unscrewing the rear element a little and gluing it in place.

 

[photodog]

There is the possiblity that the camera body is out of alignment. The lens could be ok, try using the lens on another body. If the body has been worked on, the shims that determine the lens flange to film plane distance may been taken out.

 

[sooner]

Thanks for the thoughts. I doubt it's the shims or lens flange because a different lens works fine on the camera (50 industar but not the l/d), and those pictures came out sharp. So it must be something with that lens, right? --John

 

[Sonnar Brian]

Does the lens form a decent image when held in front of a sheet of paper? The Sonnar is fairly hard to re-assemble and get a lens element backwards; the elements are in fairly big groups. The Helios-103 is a different story. Put a dot on the elements when disassembling. I winder if it has all of its elements, or if a group has separated. Shine a light through it; determine if it can form an image of the head of a flashlight.

 

[doubs43]

Sorry. I misread your lens to be the Jupiter-12.

 

[dave74]

Fuzzy J-8

Fuzzy J-8

Before tossing the lens, mail it to Maple Ridge and I'll try a re-assemble job. My own J-8 works fine now! (djb@netsplash.ca)

 

[fidget]

Before you trash anything, it couldn't be the processing could it? Negs blurry also?

A good guide may be to fix a screen to the film window and focus on a distant object. Check the image with a loupe or magnifying glass. A screen could be as simple as a piece of clear plastic from a CD case, cut to size and "frosted" with fine grade abrasive.

 

[pshinkaw]

Most people who dissassemble J-8's don't disturb the optical block because it is in one unit. The focusing helical can be lubricated independently of the optics. It is possible that someone misassembled the lens. However, it is also possible that the optics are not properly assembled as well. I have had that problem with an I-22 collapsible. It is never in focus and probably never was in focus since I acquired it in almost mint (American mint, not Russian mint) condition. It was so bad from the factory that it was unusable.

You could acquire another J-8, dissassemble both and see if anything is missing on the first one. Or, it could become a nice lens cap. Keep in mind that the set screws holding it together may be worth more individually than than a working J-8.


-Paul

 

[sooner]

Thank you all for your posts. I have decided to take David up on his generous offer of disassembling the lens for repair (hopefully), and we'll see if that does it. I will try to let you all know what it turns out to be.

--John

 

[Mike Kovacs]

I think the only one that one could get wrong on reassembly is the front element, which should have the convex side pointing towards the front (away from the film plane).