Yashica TLR focus - too far?

Discussion in 'Medium Format Cameras and Accessories' started by zesbaugh, Mar 19, 2010.

  1. zesbaugh

    zesbaugh Member

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    Just got a 635 off ebay for dirt cheap (no 35 kit, only wanted for 6*6 ability). Ugly, ugly, ugly - but shutter, ap, and timer are all in working order.

    One issue - focus at infinity is well "past" infinity.
    Close up focus is as it should be (can focus at any distance actually) but will go past infinity focus when knob is only halfway there. Then everything out of focus after that point. It's as if there's too much throw in focus, but everything is nice and tight...
    Can't quite figure out how this is possible, if close focus was off I could wrap my head around it, but close focus is fine - matches with distance scale on knob up to about 6 feet.
    Don't have film in yet to test if viewing and taking lenses badly out of whack - they appear to be on the same plane though...

    Any ideas?
     
  2. Ektagraphic

    Ektagraphic Member

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    With my Rollei, infinity is past infinity.....What you could do is place a ground glass over the film plane, set shutter to bulb, look through ground glass then once that is in focus look though the viewfinder to see if that is in focus. If they are both in focus, you are all set.....
     
  3. Ian Grant

    Ian Grant Subscriber

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    Test it with film, it's most likely fine. The viewing lens is not identical to the taking lens so don't read to much into it without using it.

    I use both a Yashicamat & a Rollei and in practice there's no problems, remember that the viewing lens is a different aperture to the taking lens

    Ian
     
    Last edited by a moderator: Mar 19, 2010
  4. Rick A

    Rick A Subscriber

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    Since you dont have any film in yet, open the back up and place a piece of waxed paper on the film plane and check the focus against the knob and the viewfinder. This will verify if all is well.

    Rick
     
  5. Ektagraphic

    Ektagraphic Member

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    I Never thought of wax paper as ground glass! :smile:
     
  6. Anscojohn

    Anscojohn Subscriber

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    Yup. Just don't use ground glass for wrappin' your samwitches!!:tongue:
     
  7. kevs

    kevs Member

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    Zesbaugh, your viewing screen could be out of alignment; the lenses won't be out of alignment with each other - unless they've been seriously tampered with - because both are fixed on the front panel, which unscrews as a single piece. The lenses are identical f3.5 Yashikor (at least on mine, some 635s have Yashinon). The 635 focuses to about three and a half feet, or one metre, so you're losing quite a lot of close-focusing ability if yours only focuses to six feet. Do the ground-glass check (I use opaque plastic stretched over the film plane) to confirm the problem, then you can have it corrected, or do it yourself if you're brave.

    My 124 G had a similar problem when I bought it.
     
  8. zesbaugh

    zesbaugh Member

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    Thanks for the focus testing idea, will give the GG/wax paper method a try tonight.

    Think maybe I didn't make myself clear about the focus issue though. I can focus down to 1M no problem, and anything in between to infinity.

    The issue is that the focus knob only needs to travel about 1/3 of its range to hit focus at infinity. Distance scale on knob shows as 3M (just a guess - didn't make note) so although inf. focus is attained the knob still has 2/3 of its range left. If you turn knob past 3M mark everything is thrown out of focus. Distance scale on knob is accurate to about 2 meters (roughly 6 feet) - hence my confusion, math doesn't add up for me. The way I see it if 3M marker on knob actually focuses at infinity then 1M shouldn't actually focus on 1M, but something further out...
     
  9. zesbaugh

    zesbaugh Member

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  10. Ian Grant

    Ian Grant Subscriber

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  11. zesbaugh

    zesbaugh Member

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    Thank you Ian, that sounds very probable as there definitely are no shims. Only a mm or two to work with but that may solve it.
    I assumed the rattle from the finder area was due to damage in shipping. Camera was thrown in a simple cardboard box with two air-pillow sheets, not wrapped or secured in any way. Tumbled around from one end of U.S.A. to the other. When the package arrived I was certain I would open only to find a very complicated puzzle of camera bits. Much to my pleasure I was mistaken.
    Yashica made one heck of a sturdy camera!
     
  12. kevs

    kevs Member

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    Zesbaugh, yes your focussing problem sounds really odd; sorry I misunderstood you. It shouldn't be possible to swing the focus between 1 metre (3.3 ft) and infinity in one-third of the travel, even with the screen out of alignment.

    Could the viewing lens have been taken apart and wrongly re-assembled? Look for silver scratch marks around the lens.

    I have my 635 in front of me as I write. If you unscrew the focussing hood's four silver screws, you'll find the screen is held in place underneath with two silver clips behind two black protrusions; it's a single unit. If you can see texture on top of the screen, it's been put in upside-down, but even so it shouldn't be that far out of alignment unless it's been bodged. The mirror could possibly cause problems if it's wrongly placed; it should be held between three metal protrusions.

    With the focussing knob at infinity, the shutter and lens assembly should be about 0.5mm from the camera body, and about 9mm when set to 3.3 ft. These distances should be the same all around the assembly. Unevenness here points to alignment problems with the focussing mechanism.

    It sounds to me like your camera has been seriously messed around with. I've taken my 635 to bits several times and seem to remember having a problem correctly aligning the focussing mechanism; it's been a while. They are lovely, sturdy cameras, a joy to use. I hope you manage to solve your problems.
     
    Last edited by a moderator: Mar 19, 2010
  13. zesbaugh

    zesbaugh Member

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    Thank you all for your help. Turned out to be missing spacers for the viewing screen. It's a miracle it wasn't shattered in transit. Some small bits of weather stripping seem to have worked well enough for now.
    And although I had no wax paper, parchment worked quite well as a stand-in GG. Brilliant suggestion!
     
  14. perminna

    perminna Member

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    I came across this topic through Google. I bought Yashica Mat EM on eBay just two weeks ago, and today I developed the test roll. It turned out that all frames are completely out of focus although I carefully focused each shot by using the magnifying glass. Camera was steadily on tripod.

    When shooting the test roll I noticed that I wasn't able to get a subject that was approx. 1 meter (3.3 feet) away in focus -- although 1m is the closest focusing distance of Yashica Mat EM. I had to take the camera approx. 2 meters (6.6 feet) away from the subject to get it in focus. The focusing knob's scale was at 1m at that time. Also the frames that were focused farther away were out of focus.

    I'm assuming it has to do something with the ground glass because the camera is in top shape. The seller says he has been using the camera without problems. The seller says that just before the camera was listed on eBay, the camera was checked by a camera store. The camera store may have broken the focusing while cleaning, right? The screws that keep the hood+glass attached to the camera body are scratched, looks like someone (the repair man) has unscrewed them recently.

    The camera arrived from the UK and I live in Finland, so complaining at the camera store is not possible. I just need to get the camera checked and fixed in Finland. It's a shame, the camera is really nice. Like new.

    // edit: I just popped up the hood again and put my finger on the focusing screen (is the top glass the ground glass?). I am able to move the top glass both vertically and horizontally. I'm pretty sure this shouldn't be possible. Missing spacers/shims?
     
    Last edited by a moderator: Dec 28, 2010
  15. elekm

    elekm Member

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    That's correct. There shouldn't be any vertical movement of the focusing screen. By the way, the glossy side should be facing up and the matte side facing the mirror.

    The focusing screen should be pressed against the inside top frame of the hood. I haven't disassembled a Yashica, but Rollei's used small flat pressure springs to keep the screen in place, and maybe Yashica copies this approach.
     
  16. perminna

    perminna Member

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    There are pressure springs that are keeping the focusing screen in place... well, the springs keep the glass on but not properly fixed. I compared the focusing screens of the new Yashica Mat EM and my older Yashicaflex and they seem alike. Glossy side up, matt side down (facing the mirror).

    Luckily the seller has promised to take the camera back if I don't get it fixed. Calling to the repair service tomorrow.
     
  17. Sayan Mukherjee

    Sayan Mukherjee Member

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    Hi Ektagraphic, I really like your signature line - "Helping to save analog photography one exposure at a time". People like you are the last rays of hope for amateurs like me!