Fixing/Replacing the Focusing Screen of an AE-1...

Discussion in 'Canon FD' started by bob_mcbob, Jun 22, 2003.

  1. I was cleaning my lenses today, and I decided to brush/blow some dust
    off the mirror (no harm there). Unfortunately, the mirror foam
    disintegrated, and went all over the focusing screen. Some of it
    appears to have removed the etching (or whatever it is) on the
    surface, so I see shiny spots from outside, and darkened spots in the
    viewfinder. It's not bad enough that I can't use the camera, but it
    is very, very annoying. I'm not certain if the AE-1's focusing screen
    is even replaceable, not that I could find a new one anyway. I can't
    think of any way to fix this problem, either... So, am I screwed?
    Obviously I'll have to get the foam replaced (is it possible to do
    this yourself?), and probably live with the focusing screen problem.
     
  2. Well, this might not be what you want to hear, but AE-1s are so cheap now, I'd say just grab another one. I recently got a black one to back up my A-1s with a 50/1.4 lens for less than $60 on eb@y. Unless it has sentimental value I'd grab a new one. Prices are so good these days you might even consider an AE-1P or an A-1. I know it sounds kinda dumb but the action grip helps out the ergodynamics of the camera ALOT!
     
  3. Yes, it does have some sentimental value (it's my father's camera). The damage to the focusing screen isn't bad enough that the camera can't be used, but it is a major annoyance. I was thinking about buying an A-1 anyway (mainly for aperture priority AE), and I might do that now.
     
  4. Hi - this is "last ditch" before you dump the camera advice I am going to give you! It worked for me with an AL-1. Not perfectly but no black flecks all over. Yes - replacing the foam is easy - I suspect that there are many previous posts here that will tell you how.

    Turn the camera over with the lens off. Get yourself some earbuds and some ronsinol. Wet the earbuds with ronsinol and gently work on the flecks (one by one) in a circular pattern. Use more ronsinol to "flood" the stain from time to time. Take your time - one fleck every night for a week? Work very slowly. Let the ronsinol work (disolve) the tar for a while. Dry with a dry cotton bud. You must work in the direction of the "grooves" if there are any.

    Remember - I told you that this is "last option" - dont try it if you have not already given up hope!
     
  5. There is no foam residue on the focusing screen, it's more like the foam rubbed off the surface in patches... let's see about a couple of photos. These are fairly small (150k in total), so I hope everyone can see them properly.

    First, from outside (through the lens mount):

    [​IMG]

    And from through the viewfinder (without a lens on... it's bloody impossible to focus on it with a lens mounted):

    [​IMG]
     
  6. I see what you mean! Maybe the previous guy used Ronsinol and earbuds?!

    It really does look like it's etched. I guess the only thing to do is to replace the screen as you said.

    BTW - fine pics of the problem!
     
  7. Well if you really want it fixed for the sentimental reasons, I'd send it to Karl Aimo, AE1REPAIR@aol.com. He CLA'ed and fixed a battery draining short on my A-1 for a very reasonable price. He's a retired Canon repair tech. Personally I would only pull the camera apart and try to fix it myself as a last ditch effort before junking it. From what I understand, replacing the focusing screen on an AE-1 is a non-trivial task best left to the pros as it requires quite a bit of disassembly.
     
  8. I find myself wondering about the answer to this question as well, as I recently bought an F-1n that came to me with a similar problem (albeit not as pronounced). I don't know what it could be about the mirror bumper foam that could cause such as caustic reaction on the focusing screen, especially when it's presumably made of glass? I do know that this foam almost turns into a sticky "goo" when it deteriorates, and will stick to and smear on almost anything it touches. Perhaps what you're seeing might be just some gobs of the foam stuck inside the ridges of the focusing screen, especially if you tried to wipe it off when it got blown onto the screen?
    So, here's my suggestion: If you feel like you've got nothing to lose by trying, pull out a Q-tip and some rubbing alcohol, dampen one end of the Q-tip with the alcohol, and GENTLY swab some alcohol onto one of the spots. Rubbing alcohol is very good at dissolving and cleaning up this gummy foam residue, and shouldn't damage the screen, so if that's all it is (some foam residue), you should be able to clean it off. Lemme know how it turns out! I'd try it myself (just thought of my solution when I read your posting), but am currently 600 miles away from my F-1...
     
  9. A quick follow-up on my previous post: EVERYONE SHOULD DISREGARD MY ADVICE ABOUT USING RUBBING ALCOHOL ON A FOCUSING SCREEN! I checked into it, and I was under the mistaken impression that theses focusing screens were made of glass; apparently, the fresnel lens surface is actually plastic, which will probably react poorly with rubbing alcohol. I was told that it's sometimes possible to clean off the rubber bumper pad "goo" from the focusing scren using distilled water. I was also told that sometimes this bumper pad residue can react poorly with the focusing screen plastic and leave scars, so it's possible that what's there on your screen is permanent.
    Sorry if I steered anyone the wrong way with my previous post!
     
  10. Hi,

    I too suffered exactly the same problem with the mirror foam disintegrating and smearing the focus screen. It is a pig to remove and I seem to have a similar melting of the fresnel.

    Anyone have names of UK/Europe repairers? I didnt think it was that much of a hassle to change (I have heard a couple of accounts so far).
     
  11. I am also looking for a replacement Focusing Screen
    for my AE-1. This scenario played its ugly hand on me as well.
    The black foam light damper turned to sludge and crumbled onto
    my mirror. I scraped it out and cleaned the mirror with qtip
    and alcohol. For good measure I cleaned the Focusing Screen
    with alcohol. This created a brown spiderweb pattern on the focusing
    screen. Alcohol + Focusing Screen == Bad JuJu (Don't do it).
    Any info on where I can buy the replacement is appreciated
    morrisonjm@coastaccess.com
     

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