Edit's will probably be required-
The J-3 is a copy of the pre-war Zeiss Sonnar, and is available in Contax/Kiev mount and in 39mm thread mount.
Both versions are built to the Contax 52.5mm standard, according to the specification sheet that came with
the "new-old-stock" 39mm thread mount versions that I bought. This typically means that the lens must be
"shimmed" to work accurately with a camera built to the Leica 51.6mm standard.
I've also found that the RF coupling in some lenses needs to be adjusted, as was necessary with this
1983 lens.
so,
1) the optics module unscrews from the focus mount;
2) Set the focus to infinity. The Focus Ring is held on by three set screws, undo them with a small jewelers screwdriver
and carefully put them somewhere safe. I use an ice-cube tray.
My Kitchen Table (when home alone!)
3) Keep the helical positioned at infinity. The Helical is held in the mount by 3 set screws. Loosen them, if too loose, place them somewhere safe. You can now move the helical
in the mount. If the lens could not drive the RF to infinity, it needs to be screwed in a bit more. If it drove the RF past infinity,
it needs to to come out a bit. You have to tighten the helical down to get an accurate reading from the camera. So, leave the helical in the infinity position, screw it in or
back it out of the mount, tighten the screws, and test it on the camera.
If the helical can't be screwed in far enough to get the RF to infinity, you need an extra step. You need to grind the mount down a little bit. Take out the three set screws
and store them safely. Take the helical out of the mount. The idea is to polish a little bit of the mount down so that the helical can be screwed in closer to the camera body.
I use some coarse sand paper for this, placing it on a hard flat surface. Move the mount over it in smooth, circular motions. Take off a little bit at a time. Thoroughly clean the
filings off of the mount and then Re-insert the helical into the mount, tighten the set screws, and check the RF alignment on the camera.
The Helical set to infinity should now couple with the camera, and show infinity for a distant object.
Now you need to get the focus ring back on, and have the distance scale read infinity. You need to
tap out three new holes for the set screws. This is a pain.
The Helical set to infinity should now couple with the camera, and show infinity for
a distant object. Now you need to get the focus ring back on, and have the distance scale read infinity. You need to tap out three new holes for the set screws. This is a pain.
I start by putting the focus ring over the helical and positioning the Infinity mark to the "thin red line". Scribe it, and ever-so-carefully begin to drill it out with a '000' drill bit.
Once the first one is done, I put in a set screw to hold the ring on and proceed to the next two screw holes.
Next up is collimating the optics module into the mount. The J-3 optics module has a variable stand-off ring that can be used for fine adjustments. Normally, I prefer to use a different shim. If the focus is really close, within 1/2 turn of the stand-off ring, I'll use it. It's held in by two set screws. Back them off, adjust the ring. You will need to tap out holes for them to be flush. The stand-off ring has to be well centered for the optics to screw in properly to the focus mount.
The screws must be flush, and it takes some practice -or trial and error- to get the taps right.
The J-3 is a copy of the pre-war Zeiss Sonnar, and is available in Contax/Kiev mount and in 39mm thread mount.
Both versions are built to the Contax 52.5mm standard, according to the specification sheet that came with
the "new-old-stock" 39mm thread mount versions that I bought. This typically means that the lens must be
"shimmed" to work accurately with a camera built to the Leica 51.6mm standard.
I've also found that the RF coupling in some lenses needs to be adjusted, as was necessary with this
1983 lens.
so,
1) the optics module unscrews from the focus mount;
2) Set the focus to infinity. The Focus Ring is held on by three set screws, undo them with a small jewelers screwdriver
and carefully put them somewhere safe. I use an ice-cube tray.
My Kitchen Table (when home alone!)
3) Keep the helical positioned at infinity. The Helical is held in the mount by 3 set screws. Loosen them, if too loose, place them somewhere safe. You can now move the helical
in the mount. If the lens could not drive the RF to infinity, it needs to be screwed in a bit more. If it drove the RF past infinity,
it needs to to come out a bit. You have to tighten the helical down to get an accurate reading from the camera. So, leave the helical in the infinity position, screw it in or
back it out of the mount, tighten the screws, and test it on the camera.
If the helical can't be screwed in far enough to get the RF to infinity, you need an extra step. You need to grind the mount down a little bit. Take out the three set screws
and store them safely. Take the helical out of the mount. The idea is to polish a little bit of the mount down so that the helical can be screwed in closer to the camera body.
I use some coarse sand paper for this, placing it on a hard flat surface. Move the mount over it in smooth, circular motions. Take off a little bit at a time. Thoroughly clean the
filings off of the mount and then Re-insert the helical into the mount, tighten the set screws, and check the RF alignment on the camera.
The Helical set to infinity should now couple with the camera, and show infinity for a distant object.
Now you need to get the focus ring back on, and have the distance scale read infinity. You need to
tap out three new holes for the set screws. This is a pain.
The Helical set to infinity should now couple with the camera, and show infinity for
a distant object. Now you need to get the focus ring back on, and have the distance scale read infinity. You need to tap out three new holes for the set screws. This is a pain.
I start by putting the focus ring over the helical and positioning the Infinity mark to the "thin red line". Scribe it, and ever-so-carefully begin to drill it out with a '000' drill bit.
Once the first one is done, I put in a set screw to hold the ring on and proceed to the next two screw holes.
Next up is collimating the optics module into the mount. The J-3 optics module has a variable stand-off ring that can be used for fine adjustments. Normally, I prefer to use a different shim. If the focus is really close, within 1/2 turn of the stand-off ring, I'll use it. It's held in by two set screws. Back them off, adjust the ring. You will need to tap out holes for them to be flush. The stand-off ring has to be well centered for the optics to screw in properly to the focus mount.
The screws must be flush, and it takes some practice -or trial and error- to get the taps right.
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I was lucky enough to find a through the lens viewer with a high-power magnifier on Ebay. Probably made for a camera repair shop, had a Canon body cap on it.
I select a couple of distances for collimation: 5m, 3m, 2m, and infinity. The J-3 is built to the Contax standard, but there was deviation. The Leica is set up for 51.6mm, so if you J-3 is on the low-end, you luck out. The various distances will help determine this.
Unless you have a TTL viewer, use a film strip or SLR focus screen at the film place of your camera. Use a Loupe to examine the actual focus. If your camera has "T", use it. Else, use "B" and a cable release with a Lock.
I select a couple of distances for collimation: 5m, 3m, 2m, and infinity. The J-3 is built to the Contax standard, but there was deviation. The Leica is set up for 51.6mm, so if you J-3 is on the low-end, you luck out. The various distances will help determine this.
Unless you have a TTL viewer, use a film strip or SLR focus screen at the film place of your camera. Use a Loupe to examine the actual focus. If your camera has "T", use it. Else, use "B" and a cable release with a Lock.
Use the RF of the camera to focus on an object at a known distance. Move the optics module in/out until the actual focus agrees with the RF. You will need to apply some pressure to keep the optics module "tight" in the mount, as the focus can shift once you use a shim. You'll have to note how much you moved it, and either make a shim or use the variable stand-off ring.
Close up of the variable stand-off ring and the shim that goes around it.
After getting the shim to your liking, and the focus to agree with the RF, you'll find the aperture ring no longer lines up. I make a scribe on the outer Rim of the optics module, because it has to come out one more time. And you want to remember where it lines up. And you want the F-Stop to line up on that spot. So scribe it, and remove the optics module. Take out the three very small set screws for the aperture ring. I set the aperture wide-open and line "1.5" up on the mark. The ring is usually screwed in, and can be tight. Once F1.5 lines up to the scribe, test that it stops down with F22 reasonably marked up on the scribe. I've seen some misengraved before, so it might be off a little. Now- tap out holes for the set screws and put them back in. The metal underneath can be thin, so do not go too far. The screws must be fairly flush, or they will rub the metal rim of the focus mount when you put it back in.
Note that if you did have to reposition the helical in the mount, like on this lens, the little red dot will be off. On this lens, it lines up with the VF. So I used it to indicate F-stop, but obviously not the focus. Many times, it will be way off and useless. On those, I paint the red dot black, and just use the white line for focus and aperture.
A few more edits to come... Including shortening the focal length on the rear group.
Until then- Kim Coxon has put together a set of instructions on a PDF here:
http://www.pentax-manuals.com/repairs/j3service.pdf
After getting the shim to your liking, and the focus to agree with the RF, you'll find the aperture ring no longer lines up. I make a scribe on the outer Rim of the optics module, because it has to come out one more time. And you want to remember where it lines up. And you want the F-Stop to line up on that spot. So scribe it, and remove the optics module. Take out the three very small set screws for the aperture ring. I set the aperture wide-open and line "1.5" up on the mark. The ring is usually screwed in, and can be tight. Once F1.5 lines up to the scribe, test that it stops down with F22 reasonably marked up on the scribe. I've seen some misengraved before, so it might be off a little. Now- tap out holes for the set screws and put them back in. The metal underneath can be thin, so do not go too far. The screws must be fairly flush, or they will rub the metal rim of the focus mount when you put it back in.
Note that if you did have to reposition the helical in the mount, like on this lens, the little red dot will be off. On this lens, it lines up with the VF. So I used it to indicate F-stop, but obviously not the focus. Many times, it will be way off and useless. On those, I paint the red dot black, and just use the white line for focus and aperture.
A few more edits to come... Including shortening the focal length on the rear group.
Until then- Kim Coxon has put together a set of instructions on a PDF here:
http://www.pentax-manuals.com/repairs/j3service.pdf
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jan normandale
Film is the other way
Brian, someone should buy you a coffee and a piece of cake for this contribution to RFF!
Yer a champ!
Yer a champ!
raid
Dad Photographer
Yes! Coffee and cake and even some sugar and creamer!
Brian is the man.
Brian is the man.
robin a
Well-known
The LENSMASTER ...............
mjflory
Accumulator
Brian, this is wonderful. Thank you.
Would the Ed Romney / Rick Oleson trick of using another camera, set at infinity, nose-to-nose with the lens-camera combination that you're collimating help with at least the infinity collimation? (I wonder how hard it would be to make a TTL viewer out of an old lens mount and some spare lens elements?)
Would the Ed Romney / Rick Oleson trick of using another camera, set at infinity, nose-to-nose with the lens-camera combination that you're collimating help with at least the infinity collimation? (I wonder how hard it would be to make a TTL viewer out of an old lens mount and some spare lens elements?)
SteveM(PA)
Poser
Thanks Brian, wow...so that's how the magic happens. I still thoroughly enjoy my "silver 84," but do let me know if you should have a spare black one. 
raid
Dad Photographer
I add my voice to Steve's. I must have a black J-3.
gb hill
Mentor
Thanks for this Brian. I have a silver J3 and I'm not to thrilled with it on my Bessa R. I guess its a 63, thats the first two #s. I'm not sure I am quite up to the task yet. I don't know too awfully much about lenses so I guess it will sit in a drawer or use it on another camera. But glad to know the info is here if needed. I have Kim Cs Pentax manuels in my favs for taking apart and cleaning.
Shortening the focal length- I've done that on two J-3s. The EFL was on the long side of 52.5mm, and could not be made to coincide with the RF over long enough range. The Black J-3 Modules changed the construction, and the rear group does not unscrew.
I removed the rear group, polished down the fixture, and screwed it back in. Bringing the rear group in closer reduces the focal length. With the J-8 and J-8, you do not have much margin between the fixture and the glass, so be careful. On one lens, I polished down part of the optics module's rear threads to get it in really close.
I'm going to expand this thread as "stuff comes back to me". I'll also get some close-ups of the shims.
Black vs Silver- I have found that the older silver lenses are a bit sharper, but the front glass is interchangeable.
1959 lens, front element replaced with one from 1986:
MORE with this lens:
http://flickr.com/photos/oldcamerapictures/sets/72157602481458663/
1983 Black lens:
I removed the rear group, polished down the fixture, and screwed it back in. Bringing the rear group in closer reduces the focal length. With the J-8 and J-8, you do not have much margin between the fixture and the glass, so be careful. On one lens, I polished down part of the optics module's rear threads to get it in really close.
I'm going to expand this thread as "stuff comes back to me". I'll also get some close-ups of the shims.
Black vs Silver- I have found that the older silver lenses are a bit sharper, but the front glass is interchangeable.
1959 lens, front element replaced with one from 1986:
MORE with this lens:
http://flickr.com/photos/oldcamerapictures/sets/72157602481458663/
1983 Black lens:
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SteveM(PA)
Poser
Brian Sweeney said:
I was thinking this was indeed the case, but I wasn't really sure...nobody's ever really talked about it before. Here's my '57...focus missed (of course) but what is sharp is really sharp. I enjoy my new '84 module, but can't get it to bite quite as much. I wonder what changed in production, and when.
Attachments
raid
Dad Photographer
Brian,
Which type of J-3 did you send me? It is sharp.
Which type of J-3 did you send me? It is sharp.
Raid, you have an older silver lens- the first one that I worked on. It is from 1963, if I remember correctly.
Adjusting the focal length by moving the rear group in: If you can't get good agreement across the focus range between the RF and the actual focus, you need to reduce the focal length of the lens. I do this as a last resort.
You can only do this on older J-3's, not sure what the cut off is. Remove the Optics Module, and unscrew the rear group from it.
I have never seen a rear group shim on a J-3 or J-8. The Helios/Menopta does use one.
So I grind down the rim on the back of the fixture that sets the spacing to the aperture. Not much room before you hit glass. Then, you have to polish down the mount. I stuff a paper towel into the mount so that the filings do not get into the aperture blades.
Make sure to get all of the filings out, screw it back together and re-test..
IF THERE IS ANY EASY WAY TO DO THIS, PEASE POST IT!
Adjusting the focal length by moving the rear group in: If you can't get good agreement across the focus range between the RF and the actual focus, you need to reduce the focal length of the lens. I do this as a last resort.
You can only do this on older J-3's, not sure what the cut off is. Remove the Optics Module, and unscrew the rear group from it.
I have never seen a rear group shim on a J-3 or J-8. The Helios/Menopta does use one.
So I grind down the rim on the back of the fixture that sets the spacing to the aperture. Not much room before you hit glass. Then, you have to polish down the mount. I stuff a paper towel into the mount so that the filings do not get into the aperture blades.
Make sure to get all of the filings out, screw it back together and re-test..
IF THERE IS ANY EASY WAY TO DO THIS, PEASE POST IT!
Close-up of the Black J-3 module, showing the rear group does not unscrew like the older lens.
The glass is held in with a retaining ring, and I have not messed with it. "Might" be possible to take out the glass and work with the fixture.
All photos with the Nikon E3, 60mm Micro-Nikkor. Flash shots woth the SB-29 Nikon Macro Light.
The glass is held in with a retaining ring, and I have not messed with it. "Might" be possible to take out the glass and work with the fixture.
All photos with the Nikon E3, 60mm Micro-Nikkor. Flash shots woth the SB-29 Nikon Macro Light.
So what changed with the Black J-3 and why isn't it as sharp... Well, it WAS NOT the front element. I used one with a 1959 J-3 and it was VERY sharp. That was a Long Shot- but it worked. I think it is the spacing of the groups in the fixture, just not as easy to play with for optimal performance. One day, I'll transplant all of the elements from a 1986 J-3 into an old fixture and see if I can sharpen it up.
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raid
Dad Photographer
Brian,
Whatever you did to create my J-3, I am very happy with it. Thanks
By the way, I met with Robin this morning.
Whatever you did to create my J-3, I am very happy with it. Thanks
By the way, I met with Robin this morning.