I bought my first EOS 3 more than a year ago (in Malaysia while I was on a visit), and yes it had the 2/3 under exposure problem. Canon South Africa fixed it for me in 10 minutes while I waited and since then the exposure is spot on. The focussing screen on this particular camera was dead centre and after a year of heavy use I fell in love with this superb camera. This prompted me to sell two of my other camera bodies (an EOS 5 and EOS 100) and just bought a second EOS 3 mail order from B&H. I was pleased to see that the exposure correlated 100 % with my first EOS 3, but the focussing screen on this camera is slightly off-centre. After searching the archives I found this explanation by Jonathan Kwok:

"So, what do you do if you find the screen slightly off centered? David Thoresen gave clear, concise instructions on the Eos mailing list on how to fix the problem. "Read all the instructions first! Lay your camera on a flat table with a lot of light (Dust free area). Looking at your Eos 3 from the front without a lens or lens cap you will see a small "latch" in the front middle upper part of the opening, right below the red dot. If you take your fingernail or very small straight head screwdriver and pull the latch *VERY GENTLY* towards you, the gate will open easily and the focusing screen will pop down. If it does not pop down you might be pulling at the wrong place. BE CAREFUL NOT TO TOUCH THE SCREEN! When it does pop down do not remove the focusing screen, because it's very difficult to clean the screen. NOTE: Sometimes just by releasing the focusing screen and pushing it back into place will center it automatically. You will see a very small 2mm piece of the focusing screen sticking out on the gate and move this part either slightly to the left or right depending on which way your rectangle problem is. This is less than a = mm of movement. To replace the screen, touch the metal part only and gently push the gate back into place. It should make a small "click" when it pops back into place. Don't touch the mirror when you are doing this. Look through your camera and it should all be lined up correctly. If not try again..."

I followed the above advice carefully and sure enough it proofed very easy. However, after repeating the described procedure several times the alignment of the focussing screen did not improve one bit. I even took the focussing screen out completely and reinstall it again - no difference. What am I doing wrong? I know it is probably no big deal since it won't affect the performance of my camera, but still it is a source of irritation.

A second annoying problem with this camera is a slight miss alignment of the LCD display panel on the top panel. In relation to my first camera the panel is situated more to the top and to the right to such an extend that the display of the shutter speed almost disappear under the black rim. I cannot recall any mention of this particular problem before. Has anyone experience this on any EOS 3. I am not near the Canon Service Centre and don't want to send the camera to them by mail. Any suggestions or must I just live with it?

-- Nico Smit (smit@landbou.uovs.ac.za), September 14, 2000

Answers

On the misalignment of the focusing screen, there is nothing you can do about this. The gap between the screen and the holding frame is negligible, therefore you cannot really move the screen to one side. In trying too hard, you will end up with a permanent collection of dust particles on the screen, which will be more annoying. You may want to consider another type of focusing screen and hope it will center - but does it worth the money ?

-- Linh Ngo Phong (npl@altavista.com), September 14, 2000.

Yep, mine also the same too. I can't notice it with standard screen but if I use my Ec-D (Grid) focusing screen this mis-alignment is pronounced. I think we have to live with it since it doesn't affect the final pics. One more thing, since I often changing focusing screen the pentaprism was invaded by dust, so EOS 3 is not really dust proof.

-- T. David (thedidavid@yahoo.com.au), September 19, 2000.