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Message |
    
Drwalker
Tinkerer
Username: Drwalker
Post Number: 1
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 10, 2006 - 11:52 pm: | 
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The focusing screen as viewed through the viewfinder on my AE-1 is very dirty. It has a large foggy halo around the center, and fogged corners as well. Is it possible to clean or replace the focusing screen? |
Glenn
Tinkerer
Username: Glenn
Post Number: 69
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 11, 2006 - 07:06 am: |
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The only way to remove/clean AE-1 screens is to remove the actual pentaprism, ie a majorish strip-down. You can carefully wash the screen in a solution of washing-up liquid. I also use Ronsonol/naphtha to clean all my Canon A and T series screens, prior to the wash.
However from your description, I do not think that the screen is the only problem. The actual pentaprism silvering could be failing or the contamination is on the surfaces of the other optical parts in the finder.
Remove the lens and point the mirror box at a brightish translucent light source (light box or similar). Hold the viewfinder approx 6"/12" away from your eye and move the camera so that you can see into the interior of the prism. The actual distance you have to hold the finder from your eye will depend on your eyesight. I am shortsighted (-9 dioptre), so I can examine things very close up without my glasses - a very positive side of shortsight. If you see a cloudiness or 'fog' then the pentaprism is the likely culprit.
The pentaprism may just have surface contamination, if not you will need a cheap junker with good finder optics. |
Drwalker
Tinkerer
Username: Drwalker
Post Number: 2
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 11, 2006 - 01:44 pm: |
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Thanks Glenn,
I tried doing as you described to examine the inside of the the pentaprism but had difficulty finding exactly what I should be looking for. But just giving the focusing screen a closer inspection it looks like the discolouration is on the inside, and therefore would require the 'majorish strip-down' in any event.
I would be willing to do this, since if I do happen to damage the camera its not a huge loss. Do you know where I could find detailed instructions on removing the pentaprism and focusing screen?
Thanks Again,
Ryan |
Glenn
Tinkerer
Username: Glenn
Post Number: 71
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 11, 2006 - 07:46 pm: |
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Ryan,
If I recall correctly, the AE-1 service manual is not available as a free download. Things might have changed because I was looking around 3 years ago. I eventually got a copy from www.lensinc.net, but there is a US eBay seller who also has the document. I do not know his details. The manual you want is not the Canon document, the one by The US organisation 'National Camera' is a much better manual. However for your specific task either manual will be OK.
If you have trouble finding a copy, contact me direct. |
Mike_rgb
Tinkerer
Username: Mike_rgb
Post Number: 8
Registered: 08-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 12, 2006 - 01:10 am: |
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I found these awhile ago, maybe they could be of some help.
http://www.canonfd.com/choose.htm
http://www.canonfd.com/a1inst/a1mind.htm
Mike |
Drwalker
Tinkerer
Username: Drwalker
Post Number: 3
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 16, 2006 - 03:00 pm: |
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Thanks for the info. I ordered a copy of the National Camera service manuals, should arrive next week. I also found an old discussion on the board dealing with the same repair. If anyone else is interested here's the link:
https://kyp.hauslendale.com/classics/forum/messages/6900/5600.html |
