CarrotRoom
Member
Just putting this out there, I think I know what I am doing but seeing if there are any other thoughts.
I recently got a Canon 7 for a reasonable price and as the only LTM/M39 lens I have is a Russian Jupiter 3 I attached it and happily went and shot the first roll.
I really enjoyed using the camera but was aware that the lens when fitted doesn't sit with the focus markings top centre, they are about 20-30 degrees passed it.
Now I realise I should have thought more deeply about this and done some more vigorous testing before committing to a roll of film but... you know... enthusiasm for a new shiny thing and all that.. so...
When I got the film back I see that the majority of the exposures are slightly soft.
After the fact then, I take the camera and focus on something of a known distance and see whet it reads on the focus ring; there is a discrepancy. Something that is 15 feet away shows as less than 10 on the lens.
So my question is; am I right in thinking that the lens mount is likely the issue here? ...rather than a badly adjusted RF. It seems fairly obvious to me that it should be the fact that the lens goes on just a little too far and so the interconnect with the RF will be off; but wanted to see if anyone had any thoughts or whether anyone else has had issues mounting a Jupiter lens to a Canon.
I think my next step is to put some sort of shim/washer on the lens so that it tightens with the focus marks at top centre and then re-check the focus. I don't have access to (and not sure, right now, I want to invest in) a proper Canon lens to compare so this seems like the easiest/best approach.
I recently got a Canon 7 for a reasonable price and as the only LTM/M39 lens I have is a Russian Jupiter 3 I attached it and happily went and shot the first roll.
I really enjoyed using the camera but was aware that the lens when fitted doesn't sit with the focus markings top centre, they are about 20-30 degrees passed it.
Now I realise I should have thought more deeply about this and done some more vigorous testing before committing to a roll of film but... you know... enthusiasm for a new shiny thing and all that.. so...
When I got the film back I see that the majority of the exposures are slightly soft.
After the fact then, I take the camera and focus on something of a known distance and see whet it reads on the focus ring; there is a discrepancy. Something that is 15 feet away shows as less than 10 on the lens.
So my question is; am I right in thinking that the lens mount is likely the issue here? ...rather than a badly adjusted RF. It seems fairly obvious to me that it should be the fact that the lens goes on just a little too far and so the interconnect with the RF will be off; but wanted to see if anyone had any thoughts or whether anyone else has had issues mounting a Jupiter lens to a Canon.
I think my next step is to put some sort of shim/washer on the lens so that it tightens with the focus marks at top centre and then re-check the focus. I don't have access to (and not sure, right now, I want to invest in) a proper Canon lens to compare so this seems like the easiest/best approach.
Ko.Fe.
Lenses 35/21 Gears 46/20
20-30 is too far. I could check my j-3 on Canon and let you know here four hours later today.
retinax
Well-known
It's common for ltm lenses to sit a bit offset on bodies of different makes, that in itself isn't an issue for focus, only for handling. Often it can be corrected.
Does this J-3 focus correctly on other non-soviet cameras? Then the issue is the camera, could be the rangefinder or the mount needing shimming. The latter would only affect the scale discrepancy, not actual rangefinder focus with a 50.
Does it focus correctly on soviet cameras? Then the lens might need adjustment to focus right on Japanese/Western cameras.
In any case, a piece of ground glass on the film rails and a loupe will tell you more.
Does this J-3 focus correctly on other non-soviet cameras? Then the issue is the camera, could be the rangefinder or the mount needing shimming. The latter would only affect the scale discrepancy, not actual rangefinder focus with a 50.
Does it focus correctly on soviet cameras? Then the lens might need adjustment to focus right on Japanese/Western cameras.
In any case, a piece of ground glass on the film rails and a loupe will tell you more.
Goody
Established
You have two different issues here.
1) The lenses on Canons, when seated fully are designed to have the mark for setting focus, and for f/stop to the left of dead center when viewed from the top. The reason is that the eyepiece is to the left of center on the camera -- so if you move the camera slightly down from your eye the marking is easier to see from that angle, to reset f/stop, for example. So that's a feature, not a lens issue.
2) The focus issue has to do with the difference between FSU (Russian) LTM lenses and German or Japanese ones -- the FSU lenses have a different back focus, so they often need to be adjusted to work correctly with non FSU bodies. I don't know if unscrewing the lens will help, but I doubt it's a great solution.
BTW the Canon 7 is an excellent camera -- so once focus is sorted you will enjoy it!
1) The lenses on Canons, when seated fully are designed to have the mark for setting focus, and for f/stop to the left of dead center when viewed from the top. The reason is that the eyepiece is to the left of center on the camera -- so if you move the camera slightly down from your eye the marking is easier to see from that angle, to reset f/stop, for example. So that's a feature, not a lens issue.
2) The focus issue has to do with the difference between FSU (Russian) LTM lenses and German or Japanese ones -- the FSU lenses have a different back focus, so they often need to be adjusted to work correctly with non FSU bodies. I don't know if unscrewing the lens will help, but I doubt it's a great solution.
BTW the Canon 7 is an excellent camera -- so once focus is sorted you will enjoy it!
Beemermark
Veteran
Are the pictures you took, using the rangefinder, in focus? If so stop obsessing about the lens distance indicators accuracy.
retinax
Well-known
1. He wrote he got soft pictures.
2. Even if rf focus was accurate, there are hard stops at both ends of the range indicated by the distance scale. Such a large discrepancy with the scale would mean the lens can't be focused all the way to both ends, close focus or infinity would be unavailable.
3.Scale focus wouldn't be possible.
Ko.Fe.
Lenses 35/21 Gears 46/20
I checked my J-3 on LTM Canon. It is very close to 12 O'clock. Even closer than 50 1.8.
AndersG
Well-known
My Jupiter-8 stops slightly left of the 12 O'clock on my Canon 7. Closer to the top than my Canon 50mm/1.4 and Canon 85mm/1.9.
In my own experience (small as it is) my Soviet lenses (J-8. J-11, J-12 and possibly I-61) focus reasonably well on my Canon 7 - but I have seldom used them fully open.
In my own experience (small as it is) my Soviet lenses (J-8. J-11, J-12 and possibly I-61) focus reasonably well on my Canon 7 - but I have seldom used them fully open.
xayraa33
rangefinder user and fancier
"Something that is 15 feet away shows as less than 10 on the lens."
With that much of a discrepancy I suspect someone in the past did a kitchen table disassembly of the lens and re-assembled the multi-start thread focus helical in the wrong start of the thread...easy enough to do and a very common mistake.
On other common problems with the J-3 : As others have stated there is also the Leica standard back focus vs the Contax based back focus of FSU lenses...most examples need to be shimmed (but not all of them need it outright).
And some of the very late made black finish LTM J-3 lenses are very soft at full bore, and nothing can be done about that other than stopping down the lens when you use it... and they are next to impossible to fine adjust properly (besides shimming) if needed...because unlike the older ones, the back optic element block is cemented and not threaded as in the past.
With that much of a discrepancy I suspect someone in the past did a kitchen table disassembly of the lens and re-assembled the multi-start thread focus helical in the wrong start of the thread...easy enough to do and a very common mistake.
On other common problems with the J-3 : As others have stated there is also the Leica standard back focus vs the Contax based back focus of FSU lenses...most examples need to be shimmed (but not all of them need it outright).
And some of the very late made black finish LTM J-3 lenses are very soft at full bore, and nothing can be done about that other than stopping down the lens when you use it... and they are next to impossible to fine adjust properly (besides shimming) if needed...because unlike the older ones, the back optic element block is cemented and not threaded as in the past.
CarrotRoom
Member
Thanks all for the responses. 
I did have this lens on a Fed-3 and I don't remember any discrepancies with the focus then, although that camera did have a light leak and I didn't have it very long.
The only other camera i have used this lens on is my MFT and it was fine but that was through the lens focusing and that would always have worked so not much of a guide; I don't remember comparing the distance with the markings but probably will tonight.
The markings being slightly left doesn't seem to be the issue then as that is expected. From what Goody and xayraa33 are saying this is either a discrepancy between FSU LTM lenses and the Japanese body OR someone tinkered with the lens.
Maybe I need to invest in a Canon lens after all and keep this for my Olympus
I did have this lens on a Fed-3 and I don't remember any discrepancies with the focus then, although that camera did have a light leak and I didn't have it very long.
The only other camera i have used this lens on is my MFT and it was fine but that was through the lens focusing and that would always have worked so not much of a guide; I don't remember comparing the distance with the markings but probably will tonight.
The markings being slightly left doesn't seem to be the issue then as that is expected. From what Goody and xayraa33 are saying this is either a discrepancy between FSU LTM lenses and the Japanese body OR someone tinkered with the lens.
Maybe I need to invest in a Canon lens after all and keep this for my Olympus
Ko.Fe.
Lenses 35/21 Gears 46/20
julio1fer
Well-known
Did you check the camera RF for accuracy? For instance, at infinite with the moon or a very distant object.
CarrotRoom
Member
Ha ha... maybe... I have a long list of projects so it will be a while before I'd get to this kind of thing; another lens would be a shorter path to shooting happiness
rfaspen
[insert pithy phrase here]
Personally, I suspect the RF in the body is off more than an issue with the lens. You need a known good ltm lens to sort everything out..... determine what and where problems lie.
CarrotRoom
Member
You may be right, I don't have another lens available to prove that so looks like I am shopping.
Not sure how I do that with a potentially suspect lens; just turn the lens all the way and see what it looks like through the VF?
retinax
Well-known
If you have calipers, you just need to know the distance of rf-cam to flange or better, film plane, at infinity or another specific distance. I can't help, don't have calipers...
xayraa33
rangefinder user and fancier
You should confirm if the RF in the Canon 7 is or is not corresponding to the lens being in focus at these medium distances.
I had to do this on my Canon 7 with a newish late made black finish 85mm Jupiter 9 lens.
Placed the camera on a tripod and RF focused on a lit light bulb...then confirmed it at the film plane and lens at full bore... with the shutter open and a piece of ground glass at the film plane using a lupe for magnified viewing.
In this case the lens was way off from the factory....fixed it by proper shimming.
You can use parchment paper if a piece of ground glass is hard to get.
*Note...some lenses had the distance scale not match with the RF...but in a minority of the cases the distant scale was separate from the main body of the lens and was held tight by 3 tiny screws and had moved and gave me a false (visual) distance scale reading.
I had to do this on my Canon 7 with a newish late made black finish 85mm Jupiter 9 lens.
Placed the camera on a tripod and RF focused on a lit light bulb...then confirmed it at the film plane and lens at full bore... with the shutter open and a piece of ground glass at the film plane using a lupe for magnified viewing.
In this case the lens was way off from the factory....fixed it by proper shimming.
You can use parchment paper if a piece of ground glass is hard to get.
*Note...some lenses had the distance scale not match with the RF...but in a minority of the cases the distant scale was separate from the main body of the lens and was held tight by 3 tiny screws and had moved and gave me a false (visual) distance scale reading.
retinax
Well-known
Did you get the J-9 to focus right over the whole range?
Re. the ground glass, it's literally ground glass. Take a shard, break it to the right size with pliers, grind one side on sandpaper or whetstone (with some water, you don't want that hard dust around lenses). Much flatter than parchmentpaper or similar.
Ko.Fe.
Lenses 35/21 Gears 46/20
Any "frosted", "milked" plastic will do.
xayraa33
rangefinder user and fancier
I got the J-9 on the Canon 7 to focus fine, maybe a little off at infinity but that would be covered by depth of field, as far away shots will not be shot at f2.
Same thing when lens hack expert Brian Sweeney shimmed J-3 lenses, he rarely got infinity 100% at f1.5 unless he shortened the back lens elements to reduce the J-3 focal length to the Leica standard on the aluminium finish J-3 lenses....the black finish late made J-3 don't allow you to do that because the rear lens elements don't unscrew but are cemented in place.
The J-9 is an excellent portrait lens...so I made sure it corresponds well with the RF on the Canon 7 at typical portrait shooting distances, and test rolls of film proved the shimming of the J-9 worked good.
You can cut a length of 35mm film width strip of parchment papers and place it in a cassette and feed it taut in the camera like film, it lays good and flat and thinner than glass and can be more accurate to judge good focus with a lupe.
Same thing when lens hack expert Brian Sweeney shimmed J-3 lenses, he rarely got infinity 100% at f1.5 unless he shortened the back lens elements to reduce the J-3 focal length to the Leica standard on the aluminium finish J-3 lenses....the black finish late made J-3 don't allow you to do that because the rear lens elements don't unscrew but are cemented in place.
The J-9 is an excellent portrait lens...so I made sure it corresponds well with the RF on the Canon 7 at typical portrait shooting distances, and test rolls of film proved the shimming of the J-9 worked good.
You can cut a length of 35mm film width strip of parchment papers and place it in a cassette and feed it taut in the camera like film, it lays good and flat and thinner than glass and can be more accurate to judge good focus with a lupe.