Focusing Screens for Canon A-1?

[brooke_read1]

Despite the wealth of information available on the web, I have yet to

discover the answer to this: What *exact* focusing screen would be

the "direct replacement" for the original Canon A-1 screen? So far I

have been able to determine that the original screen is the "Type

E". A fair number of screens marked a s Type E turn up on E*bay from

time to time, yet the box label indicates it fits the AE-1P, with no

other models listed.

 

At a recent swap meet, I noticed such a screen for the AE-1P, and

inquired of the dealer whether he knew it might fit the A-1 as well.

He seemed pretty certain that the AE-1P screen fits "perfectly" in

the A-1 -- one simply has to remove the stamped metal frame

surrounding the screen. He further pointed out that to replace the A-

1 screen, you remove the single screw at the 12-o'clock position just

inside the lens mount and slide out the small metal plate, which

appears to be the top of the mirror box. His explanation didn't go

beyond this, as he had several other customers and I didn't want to

monopolize his time.

 

To further complicate my question, I've read that the screens for the

A-1 are not user changeable -- that this must be done by a Canon

technician (take large spoon of salt here).

 

I'd be grateful for any information from you Canon experts out there!

 

Kind regards,

[awahlster]

Brooke the only screens that will work in an A-1 are A-1 screens

 

#A micro prism center matte field

 

#B Split image on a matte field

 

#C All Matte field

 

#D All matte with a Grid of lines

 

#E Split image surounded by Micropeism donut on Matte field

 

#F Special Microprism for fast lenses

 

#G Special Microprism for slow lenses

 

These can be replaced by a very very careful owner that knows what they are doing but would be best for mosat people to have this done by a service tech/ repair person. I won't go into the details but it does involve some disassembly of the screen support frame.

 

The idea that you can so how disassemble a AE-1 sceen and get it to fit in an A-1 has been around a while but owning both I don't see how it would work as the AE-1 Screen is close to 1/4" thick with the lens above it and the A-1 screen is about 3/32" thick just a flat pc. of glass.

 

Mark W.

 

PS keep looking they are out there but rare.

[chuck_hoffman]

Go to <a href="http://www.horizon-electronics.com">this web site</a>, copy down the toll-free number and give them a call. Horizon Electronics is a Canon-authorized repair station and probably (does more work on)(has more parts for) A-series Canons than any other shop in the country.

[brooke_read1]

Mark and Chuck, Thanks for both of your helpful replies - I knew I could count on some of expert advice out there! I just checked out the Horizon Electronics website, and will inquire. I'll also keep them on hand as a future repair reference; sounds like a good contact!

 

Good shooting and Best regards,

[alan_swartz]

Hi Brooke,

 

I don't really have anything new to add but a little personal experience.

 

I wouldn't say that the AE-1P screen would fit "perfectly" after disassembly. I have both types in front of me, and the screen, less the frame, is different from the A-1 screen. The AE-1P screen has three mounting points on the long sides where the frame grasps it. The A-1 screen has protruding lips that run the length of the long sides. Though their thickness is nearly identical, I'd wonder if the AE-1P screen would align properly in the A-1.

 

I've successfully changed my A-1 screens. I too would recommend it only to an experienced soul. The tiny screw at the top must be removed without stripping the head. The thin metal piece it holds (which bears the mirror foam) is essentially flat. Don't drop the pieces in the shutter curtains, or scratch the mirror. I remember that installation is trickier than removal. The screen is under some spring tension when installed, so you have to nurse the screen, the plate, and the screw all together while compressing it into place.

 

The screens are soft plastic, by the way, very susceptible to damage.

 

A tangent that might also be of interest. . .I studied AE-1P and T90 screens by eye, and could not tell a difference. Armed with courage one night, emboldened by the rarity of T90 screens, I put an AE-1P screen in the T90. It was seemingly perfect fit, though I never tried taking any pictures with it. So I tried the T90 screen in the AE-1P. It doesn't fit--won't latch into place. Moral of the story: invisible differences in screens?

 

A-1 screens do turn up on eBay sometimes, and they at one time sold for fairly reasonable prices.

 

Good luck!

[brooke_read1]

Hi, Alan -

 

Thanks very much for your detailed, insightful and most helpful reply. Your post will become part of my (voluminous) file of reference material! I've changed many a screen without "major" disassembly, but I think I'll play it smart and let the pros handle this one. The source of all this is a beautiful, mint Canon A-1 which I inherited a couple of years ago. Absolutely perfect save for the screen, which must have suffered an attempt to clean it with a liquid(?) of some sort. I'll contact Horizon Electronics and have them do the replacement should they have the E screen in stock; otherwise I'll keep my eye on E*bay and the used market. I know one will surface in time (things *always* do)!

 

Kind regards,

[john_tribe]

Brooke,

 

Further to previous advice:

The AE-1P screens are slightly larger than the A-1 screen. In order to fit one into the A-1, you would have to remove it from it's frame (bend the retaining clip), remove the two locating tabs from the plastic screen and remove a mm from either side (file/scrape). This sounds very crude and can not be recomended. It should also be remembered that the AE-1P screens are slightly brighter than the A-1 screens and may cause the metering system to read higher than normal?

 

Removing the front plate from the A-1 however does seem to be a good way of re-placing the mirror foam tho'!

 

Boggy