AF confirmation lights - out of alignment - 350D

Anyone know how the red AF lights are aligned to the squares in the viewfinder - i.e. where are the bulbs and how do they hit the squares?
My 350D now shows the lights slightly to the right of the AF zones. Without proper alignment with the dots, they 'glow' rather than show as a sharp dot. The image here shows that the lights are all working and then have a broad spread over the bottom of the viewfinder but they are dim on one side.

I have a fully charged battery so the dimming is not due to power - it could however be due to age   .... but the alignment is my main concern.

The actual focus mechanism seems to be functioning correctly - I have tried with 2 lenses, so the problem is only in the viewfinder.

If I always select the centre spot then the audible beep is enough for me, but if I enable all AF zones, I can not really tell which ones have achieved focus.

I don't know how much this information will help, but here goes...

On that model (and as far as I know, the entire Rebel line), the focus screen carries small stick-on reflective dots that provide the pinpoint indications. If those dots come off, all you'll get is a weak, dull glow from the general reflectiveness of the focus screen. Generally speaking, the glow will tend to be stronger at the bottom of the viewed image simply because that area is usually darker than other areas.

The focus screen could be out of alignment, or it could have lost some of the reflective dots. New focus screens are relatively cheap -- Canon part number YN2-3472-000 for the XT/350D. It used to be maybe $5 US from Canon (but the cost of shipping more than doubled that), $25-30 US from third-party suppliers, cheaper on eBay and the like. Personally, I'd order from Canon if possible.

Removing and replacing the focus screen is, in concept, a simple process. In practice, it can be a bit fiddly and a bit hard on the nerves (you don't want to scratch the mirror). Basically you remove the lens and turn the camera upside down so that it's sitting on the flash shoe. There's a spring clip that holds the focus screen in what is, for the moment, the bottom of the mirror box. The clip's got a curled lip that you can push on to unhook it, then you can lift the clip out. Right below that is the focus screen, which you can lift out (tweezers are very useful).

Some cautions:

1. Blow out as much dust as possible from the mirror box before you start dismantling. Any dust that gets into the pentaprism area after you've lifted out the focus screen will probably make you crazy.
2. Don't scratch the reflex mirror. It's silvered on the front side, where you're working.
3. Don't scratch or contaminate the focus screen. They're almost impossible to clean, and scratches will be permanent.
4. Pay attention to the orientation of the focus screen when you take it out, so you can put it or its replacement back in the correct way. There are 3 wrong ways and one right way.
5. Below the focus screen is probably a metal shim. If you accidentally drag that out, you'll want to put it back in before you put the focus screen back in.

After you've replaced the focus screen comes the most fiddly part: latching the spring clip. Make sure that all four legs of the clip are sitting on the focus screen, not hanging off the edge. When you've got it into position, be sure that you've gotten the catch fully latched. Otherwise, the first time you take a picture, the reflex mirror will dislodge the whole mess and it'll come crashing down into the mirror box.

mmm? I 'think' that procedure may be a bit much for a 10yr old camera.
But, thanks, it has explained a lot.

I just took another look at the focus screen and compared with my 400D.
the lights are definitely off-centre. So even if the focus screen is intack, the lights are missing their targets.
Do you have any idea where the LEDs are situated? could they be in the top of the pentaprism?

I`ve seen a lot of 350Ds where the AF pinprick lights are barely functioning at all - its as if the lightsource is failing and can`t focus on the viewfinder area in the right place or at all - thankfully the 350D was the last "rebel" to have a real secondary LCD and it displays which AF point is working .

I`d be thankful it works at all - the 350D was the first of the "tiny'n'cheap" canon DSLRs with cheaply made innards so 10 years is doing really well ..... BTW I bought one as a backup in March 2005 , it cost £650 with the 18-55 from Jessops in Chester (when they had two shops there) . it went back twice in the same month , first for two buttons failing on the back and secondly because the AF was inconsistent . they never did fix the latter and I gave up and replaced it with a used 20D for backup.

I have done my annual sensor clean and at the same time gave the mirror and the underside of the pentaprism a good clean.
Now, the centre 3 and 2 right AF lights are working a bit better. They do partly illuminate the dots.

10 years is not bad for a dSLR. I did manage to pick up a 400D + 18-55II + 8GB card for £50 recently. And as long as I'm still getting top results in competitions at my camera club, the wife sees no reason to upgrade ... with cash being tight, she can always find places to spend spare money quicker than I can.

SkIz wrote:

I would really like a follow up on this as my 5D Mark II does the same thing.

Sorry for the delay in replying Sklz,

Unfortunately, I didn't get any further with my investigation.

In my previous post I commented that I had moved to a 400D ... and at that time my daughter used the 350D for a while. In Feb this year I got a 70D and my daughter uses the 400D .... so the 350D doesn't get used at all now.

But, I switched on the 350D yesterday and it is still focusing well so the light issue is NOT affecting any AF functionality. And everything else works well after almost 40K shots.

My only guess at the problem is that due to age of the lights and the dots wearing off, the red spots are not so well defined.

Does your 5D still focus correctly?   Is is just the red-dot confirmation light in the viewfinder that is a problem?
If so, you could try cleaning the mirror and also the underside of the prism (obviously being very careful with the mirror as any pressure could affect it's alignment)