EOS 3 AF points

TimmyMac · Jun 12, 2010

I'm wondering if anyone else has this problem and/or knows of a fix... I did a quick search but nothing turned up

The AF points on my EOS 3 are slightly tilted (maybe 3-5 degrees) and skewed (about a half to one AF box downwards) so they don't like up properly with the ellipse in the viewfinder. Presumably the light that projects the points onto the focusing screen has moved slightly?

flatulent1 · Jun 14, 2010

Is the focusing screen properly seated?

TimmyMac · Jun 14, 2010

Yep, manual and autofocus focus accurately so it's presumably not the focus screen. I wonder if there's a way to open up the prism area and realign the projector?

SilverGlow · Jun 15, 2010

I wonder is something is damaged in your EOS 3...I have three bodies and none of them have this issue....I would remove the focus screen, clean it, clean the area where it gets inserted too....maybe just send the body in for a general CLA....

film_man · Jun 16, 2010

When you say autofocus is ok, do you mean it autofocuses properly where the "tilted" point is or where the point "should" be? The AF points on my EOS 3 don't line-up exactly either, they are all a tiny bit to the right (which is most obvious at the centre point), based on the circular area of the screen.

This is due to the screen not being seated properly. By that, I mean that the screen is seated ok as far as manual focusing (manual focusing is affected by the distance between screen-mirror-viewfinder, autofocus is done on the mirror so the screen is irrelevant) is concerned but there is still a bit of give left/right, so you might want to try and reseat it.

I found the best way to do that is to turn the camera upside down, unlatch the screen holder so the screen can move around, then look through the viewfinder (camera still upside down otherwise the screen will fall off!) and tap the body lightly left/right/back/front until the screen is where you want it to be.

TimmyMac · Jun 16, 2010

As far as I can tell, it autofocuses where the AF points should be. Otherwise it wouldn't really be a problem. I've tried reseating the screen and switching it out for my EOS 1N screen, neither helped. It's been like this since I got the camera as well. Anyone know if a repair manual is available?

flatulent1 · Jun 17, 2010

An EOS 3 isn't really a DIY repair sort of camera. If it were mine I would take it to the nearest reputable repairman, or even contact Canon Service.

Poisson Du Jour · Jun 17, 2010

A warped screen frame, through exerting too much pressure during re-seating, is the most likely cause.

Echoing a previous post, investigation and remedy is not a DIY task and is best left to a service centre.

film_man · Jun 17, 2010

Well if reseating the screen doesn't fix it, then as many said it looks like a repair job for the service centre.

SilverGlow · Jun 17, 2010

Poisson Du Jour said:
A warped screen frame, through exerting too much pressure during re-seating, is the most likely cause.

Echoing a previous post, investigation and remedy is not a DIY task and is best left to a service centre.

Actually changing out the screen is in fact a user task. When you buy a replacement screen the package even comes with a little tool to unseat and seat the screen...it is very easy. I have found that the use of this tool is optional. Unless an owner is very, very incompetent to easy mechanical process I would not suggest going to a pro shop.

Now of course if we're talking about a damaged camera, then of course a factory rep or a camera pro would be the best bet.

TimmyMac · Jun 19, 2010

To be honest I only spent $100 on the camera, I'm not looking to send it to a shop and I'll live with the off centre AF lights if necessary. I was wondering if anyone else experienced this and if it's a common problem or not.

flatulent1 · Jun 19, 2010

The focusing screens are the same as for the EOS 1V, and seven are still available. Check them out. They're only $32.

2F/2F · Jun 19, 2010

SilverGlow said:
Now of course if we're talking about a damaged camera, then of course a factory rep or a camera pro would be the best bet.

That is exactly what he was talking about, and I also agree with his prognosis. The screen is not sitting properly in its place, likely because its place is tweaked.

flatulent1 said:
The focusing screens are the same as for the EOS 1V, and seven are still available. Check them out. They're only $32.

Indeed. However, the ones that were introduced after the EOS 3 (such as the type S) will cause the camera to meter improperly, so if you use your in-camera meter, take care to get one that works with the 3's meter.

Personally, I got the S screen anyhow, since I don't ever use my in-camera meter. Works like a charm.

flatulent1 · Jun 19, 2010

2F/2F said:
That is exactly what he was talking about, and I also agree with his prognosis. The screen is not sitting properly in its place, likely because its place is tweaked.

You make a very good point, one that I had not considered. The focusing screen is frameless, therefore a new screen would likely do no good. It would almost have to be the seating in the camera body. Best have a pro look at it, if it's something you care about. Personally, that sort of thing would drive me nuts, and I would be delighted to spend whatever (within reason) getting it fixed.

TimmyMac · Jun 19, 2010

Pretty sure it's not to do with the screen. I reseated the screen, tested a different screen, reseated the different screen, removed the screen entirely, nothing changes the skewed position of the AF point lights.

Poisson Du Jour · Jun 22, 2010

The AF points are superimposed onto laser-etched markings on the screen matched to emitters lined up directly above, and of course, any misalignment of the screen will be very obvious. I think a more sinister proposition is that the camera has received a severe knock that has bumped the superimposition emitters out of alignment, but at the very most, such misalignment would manifest as only a little more flare — that is to say, flare that is significantly more noticeable and adverse than normally occurs during the illumination process. The effect has been seen in several well-used and battered EOS 1/1N bodies where the screen has been frequently interchanged.

Warped screen frames are the most common problem where changes have been made hurriedly, clumsily or incompletely — it is a delicate operation with the potential for damage to the screen especially from slippage with the tool, or damage to the frame by forcing an incorrectly seated screen. Irrespective of how much you paid for the camera, a bench examination by a qualified professional is called for now that everybody here has proferred as much as can be without actually physically inspecting the body.

ath · Jun 23, 2010

The screen of the EOS 3 has no markings for the AF points. They are simply projected on the screen. The 1 and 1N have different screens with markings.

TimmyMac · Jun 23, 2010

In the 1N, the markings are etched into the prism (not the screen). On the 3, neither the screen or prism has any etching - I think the AF lights are projected like a reflex sight. Presumably the only thing that could misalign them is the projecting device being off then? Which would be deep inside the camera body - I think I'll just live with it!

EOS 3 AF points

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