Adjusting AF focus on a canon 20D

[puggie]

I have a 20D which I am pretty confident is missing the mark with AF, on wide aperture stuff it tend to not focus where I want. I fitted a Katzeye split prism screen as I use a fair few MF M42 lenses and with the split prism I can get the focus spot on, with the AF it rarely is quite as accurate (this was most noticeable comparing my Canon 50mm f1.8 to Pentax 50mm F1.4).

So I'm aware it is the little secondary mirror behind the main reflex mirror that reflects onto a light sensor in the bottom of the camera, to AF. Is this something I can tweek myself to adjust the focus point? I have read a couple of generic web pages about adjusting focus this way, just wondered if anyone had done so.

 

[scottthehat]

no you cant adjust it, on newer cameras they have micro adjustment built in, some cameras you can find debug modes(service mode) where you can go in and adjust the focus but that only adjusts for every lens (unlike having it in the newer camereas you can adust for 20/30 lenses).
send it back to canon with some lenses(but it could be your lenses that are off).

 

[CT]

I believe there's an adjustment screw in the camera body which is used to calibrate the lens to the body, but whether it''s something you can access yourself I've no idea. You'll probably get the definitive answer from Canon Bob. If he doesn't see this post try dropping him a PM.