Group: Member
Post: 5 (0 liked)
Join date: July 2021
Status:
|
|
on Jul 18, 2021 8:13:30 GMT
Posted: Jul 18, 2021 8:13:30 GMT
Hello everyone,
I bought a Yashica D in very nice condition a while back. (I'm new to TLR cameras, however)
I've shot a couple rolls through it, but very few of the pics are sharp.
When I do get it sharp, they are very nice, but my recollection now is that the ones that are the best seem to be @ f16 or 22.
Even with the magnifier, my shot looks about as focused and sharp as I can get it before I hit the shutter button...but most aren't sharp after I develop them.
I read that the taking lens and the seeing lens can be off, but this camera is in really nice shape and even measuring with the lens focused all the way out shows equal spacing from the top to the bottom. It doesn't appear to have been dropped or knocked in any way.
Does anyone have any info on how to calibrate those lenses or can point me in a direction that can help with making sure the lenses are correct?
It's either they're out of sync, or I just am not focusing properly. It could be either I suppose, but it looks focused in the viewfinder.
I did take out the lenses and clean them as well as the mirror. They were dusty and spotty... maybe I screwed it up.
Anyway, any help would certainly be appreciated.
Thanks!
|
|
Deleted
Group: Member
Post: 0 ( liked)
Join date: January 1970
Status:
|
|
on Jul 18, 2021 11:59:31 GMT
Posted: Jul 18, 2021 11:59:31 GMT
Welcome to the forum, lycosa!
As to the issue you reported, one question--does your camera sport the original focusing screen? I'm asking because I had such a focusing problem myself (back-focus) with an East-German Pentacon Six from eBay, and it turned out the new focusing screen that the seller had inserted was misaligned.
With medium-format cams, film flatness--or rather, the lack of it--might be another issue to check out.
Michael
|
|
Group: Administrator
Post: 1,409 (314 liked)
Join date: February 2017
Status: Failed treatment for L.B.A. and G.A.S,
|
|
on Jul 18, 2021 16:57:33 GMT
Posted: Jul 18, 2021 16:57:33 GMT
The only TLR repairs I've done so far have been on the cosmetic side, but I have done some focus corrections on SLR lenses and in setting cams on LTM type rangefinders. They were possible because of how each one was designed and engineered to have some built-in adjustability. I'm not sure just how much of that would be available on a Yashica D specifically, but I do know that to maintain the required precision in the entire 'optical path', many times brass or paper shims were used - in singles, at micron thickness precision, or multiples as precision stacks of singles - to modify spacing as-needed. Sometimes calibration requires an optical bench and/or a lens collimator, and those aren't exactly cheap or in plentiful supply on the used market, and are better left for repair shops to tackle for you. There is one thing that might offer a clue on where to look to diagnose the problem, but not give any instruction on how to affect a fix... a Yashica D assembly chart is available as a PDF file. With a very quick look through, it doesn't show any adjustment points that might affect focusing, but that won't mean they don't exist as part of a named assembly on the chart. You'd just have to know where to look once inside. I'd suspect shims are needed, and not adjusting a screw on TLR's. It might be possible to get a sense of what piece of the puzzle might be misaligned. If you have - or can make the equivalent of - a small plate of ground glass, you can place it on the film plane and see if the viewing path and the taking path match. If they're both out of focus, it might be a pressure plate issue, or if one or the other is out of focus, it might narrow down what subsystem needs adjustments. 3M 'invisible tape' on a very stiff sheet of clear plastic can be a reasonable one-time substitute for ground glass in a pinch. I'd be remiss if I didn't offer one caution. There's the distinct possibility that things can be returned in a reversed position, or have something disappear during disassembly that we aren't aware of... and once reassembled it just isn't quite the same as before. That's not to suggest that the fault lies with you, but it might have been due to any earlier owner/tinkerer trying their own fix and failing. There's at least one person on the planet who does know how to fix a Yashica D, and certainly has the calibration tools to bring it back to a working state. Try to contact Mark Hama through his website if you might want his services.
|
|
Group: Member
Post: 5 (0 liked)
Join date: July 2021
Status:
|
|
on Jul 18, 2021 17:22:43 GMT
Posted: Jul 18, 2021 17:22:43 GMT
Welcome to the forum, lycosa!
As to the issue you reported, one question--does your camera sport the original focusing screen? I'm asking because I had such a focusing problem myself (back-focus) with an East-German Pentacon Six from eBay, and it turned out the new focusing screen that the seller had inserted was misaligned.
With medium-format cams, film flatness--or rather, the lack of it--might be another issue to check out.
Michael
I believe it does. It came with a bunch of accessories in a steel box that was foam lined. It has expired film from the 60's in it. It honestly looks like a time vault. If it had been replaced, I probably wouldn't know it. However, it really does look like it is all original from what I've seen of other people's Yashica D's.
|
|
Group: Member
Post: 5 (0 liked)
Join date: July 2021
Status:
|
|
on Jul 18, 2021 17:37:24 GMT
Posted: Jul 18, 2021 17:37:24 GMT
The only TLR repairs I've done so far have been on the cosmetic side, but I have done some focus corrections on SLR lenses and in setting cams on LTM type rangefinders. They were possible because of how each one was designed and engineered to have some built-in adjustability. I'm not sure just how much of that would be available on a Yashica D specifically, but I do know that to maintain the required precision in the entire 'optical path', many times brass or paper shims were used - in singles, at micron thickness precision, or multiples as precision stacks of singles - to modify spacing as-needed. Sometimes calibration requires an optical bench and/or a lens collimator, and those aren't exactly cheap or in plentiful supply on the used market, and are better left for repair shops to tackle for you. There is one thing that might offer a clue on where to look to diagnose the problem, but not give any instruction on how to affect a fix... a Yashica D assembly chart is available as a PDF file. With a very quick look through, it doesn't show any adjustment points that might affect focusing, but that won't mean they don't exist as part of a named assembly on the chart. You'd just have to know where to look once inside. I'd suspect shims are needed, and not adjusting a screw on TLR's. It might be possible to get a sense of what piece of the puzzle might be misaligned. If you have - or can make the equivalent of - a small plate of ground glass, you can place it on the film plane and see if the viewing path and the taking path match. If they're both out of focus, it might be a pressure plate issue, or if one or the other is out of focus, it might narrow down what subsystem needs adjustments. 3M 'invisible tape' on a very stiff sheet of clear plastic can be a reasonable one-time substitute for ground glass in a pinch. I'd be remiss if I didn't offer one caution. There's the distinct possibility that things can be returned in a reversed position, or have something disappear during disassembly that we aren't aware of... and once reassembled it just isn't quite the same as before. That's not to suggest that the fault lies with you, but it might have been due to any earlier owner/tinkerer trying their own fix and failing. There's at least one person on the planet who does know how to fix a Yashica D, and certainly has the calibration tools to bring it back to a working state. Try to contact Mark Hama through his website if you might want his services. Thanks for the advice! While researching the problem, other people gave the same advice to others about placing the tape or ground glass and creating what some have called an 'infinity well'. I'm still not sure on how to inspect the lenses this way. Would that mean looking through the front of the lenses to the back film plane with the shutter open? Which I suppose wouldn't work for the viewing lens anyway. If you would, could you please elaborate a little more on how to do that? I've found a guy in Orlando that does a complete CLA on TLR cameras for $175 which I think is fair. I'm the type that loves to work on cameras myself (perhaps to my own detriment). I've done fine with maintenance on my SLR cameras, but this TLR is a different animal. I was very careful when cleaning and didn't lubricate anything since everything worked fine including the self-timer. If I can't solve this on my own, then I will be sending it to be serviced. The camera is in too nice of condition to let it go. Even the leather case and strap are in near mint condition. I'd rather take the time to understand it myself well enough that I can service it when it needs it, but maybe this one is out of my league.
|
|
Group: Administrator
Post: 1,409 (314 liked)
Join date: February 2017
Status: Failed treatment for L.B.A. and G.A.S,
|
|
on Jul 18, 2021 21:41:59 GMT
Posted: Jul 18, 2021 21:41:59 GMT
Essentially the idea on using a ground glass to evaluate with, is to have it take the place of the film at the rear of the camera while the back is open. When the lens is in the 'bulb' position, it can be triggered and the aperture will remain open while the focus is checked. I've used a cheap 8x magnifier to place on a trimmed-down piece of thin plexi + frosted tape, where the tape side acts as the film at the film plane. You might need to use a dark cloth or something similar as a light block to see it clearly. It's the basic focusing technique used on large format cameras, and on rangefinders and SLR's it works really well for all kinds of maintenance tasks. Set up a non-moving set of objects and use the hood and loupe normally to get the best focus, then check the focus the film would get with the 'ground glass' placed inside the film guides. You might have to be a bit creative in setup and holding the camera in a stable position, since the tripod mount is attached to the film door and swings up/out when it moves, but I'd think it should be possible to get something to work well enough. Using string through the strap lugs to anchor the back in it's upright position comes to mind for a start. On TLR servicing... Mark Hama worked at the Yashica factory in Japan, and was also a senior repair tech once he'd moved to the US. He prices his repairs based on the actual work involved so I'm not sure how to compare pricing, but he has a reputation for reasonable costs and high quality work. He got ALL the spare parts Yashica had left for the 124G TLR's when the factory closed, so if you ever buy one of those, he might be your only hope for parts.
|
|
Group: Administrator
Post: 1,409 (314 liked)
Join date: February 2017
Status: Failed treatment for L.B.A. and G.A.S,
|
|
on Jul 18, 2021 23:35:05 GMT
Last Edit: Jul 18, 2021 23:39:01 GMT by lumiworx
Here's a photo of what I'd normally use for 35mm bodies, but 'adapted' to fill the same role on a Yashica A TLR. The plastic piece is frosted on one side, and it's placed closest to the film chamber. Depending on how thick the plastic/glass sheet is, it might require reversing the magnifier lens 180 degrees to adjust the physical distance to the frosted 'plane' that's acting as the film, to get the loupe in-focus to your eye. Normally if you leave the clear cup sitting on the surface, whatever it's sitting on 'should' be in perfect focus, but if it's off by @ 1.58 mm (1/16"), like this is, it gets reversed. The plastic sheet itself was part of a tabletop business card holder that I took apart to get a suitable sized piece of plastic that was already 'frosted' on one side, then trimmed with a razor saw to get the right width.
|
|
Group: Member
Post: 5 (0 liked)
Join date: July 2021
Status:
|
|
on Jul 19, 2021 0:24:48 GMT
Posted: Jul 19, 2021 0:24:48 GMT
Here's a photo of what I'd normally use for 35mm bodies, but 'adapted' to fill the same role on a Yashica A TLR. The plastic piece is frosted on one side, and it's placed closest to the film chamber. Depending on how thick the plastic/glass sheet is, it might require reversing the magnifier lens 180 degrees to adjust the physical distance to the frosted 'plane' that's acting as the film, to get the loupe in-focus to your eye. Normally if you leave the clear cup sitting on the surface, whatever it's sitting on 'should' be in perfect focus, but if it's off by @ 1.58 mm (1/16"), like this is, it gets reversed. The plastic sheet itself was part of a tabletop business card holder that I took apart to get a suitable sized piece of plastic that was already 'frosted' on one side, then trimmed with a razor saw to get the right width. Thank you so much for taking the time to explain this. This is exactly what I needed. I've read it on other forums before but without any level of detail on how to accomplish it. I have a loupe just like that. I may have to get creative in the setup, but at least I have a guide on how to go about it. At least now I have a direction and if it gets beyond my ability, I'll check out Mark Hama as you've referred. I really do like servicing these old cameras myself and it's just something I've aspired to be good at. It has all the complications and complexity to make it challenging and fun. But! There comes a point where I have to let some things go to the professionals. Working on these old cameras seems to be a dying art and I only hope some of these experts mentor enough people to keep the vocation going into the future. Thanks a bunch!
|
|
Group: Administrator
Post: 1,409 (314 liked)
Join date: February 2017
Status: Failed treatment for L.B.A. and G.A.S,
|
|
on Jul 19, 2021 9:56:28 GMT
Last Edit: Jul 19, 2021 16:06:27 GMT by lumiworx
You're welcome, lycosa ... and take a peek at some of the simple things too that tend to get overlooked, like a weak spring on the pressure plate, or a guide roller that popped out of it's hole. Sometimes we fixers can overthink a problem, and conclude it must require a complex solution, when it's often quite the opposite.
|
|
Deleted
Group: Member
Post: 0 ( liked)
Join date: January 1970
Status:
|
|
on Jul 19, 2021 15:29:30 GMT
Posted: Jul 19, 2021 15:29:30 GMT
I did take out the lenses and clean them as well as the mirror. They were dusty and spotty... maybe I screwed it up. Did you remove the viewing lens completely? The lens is in a threaded mount and needs to be adjusted to match the focus to the taking lens. Did you do that?
|
|
Group: Member
Post: 5 (0 liked)
Join date: July 2021
Status:
|
|
on Jul 19, 2021 21:32:43 GMT
Posted: Jul 19, 2021 21:32:43 GMT
I did take out the lenses and clean them as well as the mirror. They were dusty and spotty... maybe I screwed it up. Did you remove the viewing lens completely? The lens is in a threaded mount and needs to be adjusted to match the focus to the taking lens. Did you do that? I did remove the lens completely going by a YouTube video and I did not match the focus. The guy never mentioned that. I have a lens tool and just popped it back in and secured it reasonably tight. That could be the problem... if so I suppose the recommendation above would fix that as well by loosening the lens to a focal point? I figured the focus would match as the lens seated tight...
|
|
Deleted
Group: Member
Post: 0 ( liked)
Join date: January 1970
Status:
|
|
on Jul 20, 2021 19:18:50 GMT
Posted: Jul 20, 2021 19:18:50 GMT
Did you remove the viewing lens completely? The lens is in a threaded mount and needs to be adjusted to match the focus to the taking lens. Did you do that? I did remove the lens completely going by a YouTube video and I did not match the focus. The guy never mentioned that. I have a lens tool and just popped it back in and secured it reasonably tight. That could be the problem... if so I suppose the recommendation above would fix that as well by loosening the lens to a focal point? I figured the focus would match as the lens seated tight... I'm still not sure exactly what you did. In the pdf diagram that Lumiworx linked to, on page 3, item 6D-092-2 Lens Barrel. Did you remove that? Or did you just remove the glass elements from the barrel? It's the barrel that get's adjusted to match the focus with the taking lens. There's a locking screw (item 6D-189) that locks the barrel once it's been aligned. Even if you didn't remove the barrel, maybe someone else did. Unlocking the screw and rotating the barrel is the way to align the lenses.
|
|