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I had it checked in case it needed repair, but they said they could not find a problem with it. I really need help on this one.

[the process]

I turn the camera on, select M mode, select the top focus point in auto-focus, it turns red when I press the button to make a photo, but when I look at the bottom part it's clear. It obviously focuses on that part.

I also tried the manual focus, but the result is the same.

[lens]

I tried with two different lens that were checked recently and are in perfect condition. I could upload an image I suppose.

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  • \$\begingroup\$ Could you edit your question to describe the full process you go through in order to reproduce this problem (Turn camera on, put into Av mode, select central AF point,...) and possibly an example image to help the diagnosis please. \$\endgroup\$
    – Edd
    Aug 29, 2012 at 10:27
  • \$\begingroup\$ It's interesting that manual focus produces the same result; do you have a sample image or a secondary lens that you could try using? \$\endgroup\$
    – Edd
    Aug 29, 2012 at 11:48
  • \$\begingroup\$ I think if you can shoot some sample images that would most likely be best. If you look through your viewfinder, your eyes will refocus if the difference is small. If you could offer some systematic sample images, that might help us to get an idea. Say a newspaper at a 45 degree angle. Top AF point, then centre, then bottom without moving the camera or newspaper on a wide aperture. If your focus is consistently out by a small amount it might just an issue of tolerances adding up the wrong way: canonrumors.com/tech-articles/this-lens-is-soft-and-other-myths \$\endgroup\$
    – DetlevCM
    Aug 29, 2012 at 17:50
  • \$\begingroup\$ Manual focus causing the same problem sounds like a severely decentered lens, or insufficiently supported heavy lens, or a damaged lens mount... \$\endgroup\$
    – rackandboneman
    Aug 15, 2019 at 21:02

1 Answer 1

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Spontaneously, what AF point is selected? You have not got the lower AF point selected by any chance?

One of the buttons used for zooming during preview (top right - I think the right one) in conjunction with the "shutter-wheel" will allow for AF point selection. If one AF point lights up in the viewfinder, only that point is used for focusing. I think all points light up when the camera selects the AF point.

You also have not said what shooting mode you use - I assume it is not "Auto" (aka green" box) which on a 400D overrides the AF mode, but on a 5D MK II it does not. (If you scroll down on this 5D MK II review, there is an image of the back of the camera: http://the-digital-picture.com/Reviews/Canon-EOS-5D-Mark-II-DSLR-Digital-Camera-Review.aspx -> the set of three buttons, AF-On, -, + is the one I am reffering to - you want the + button)

In case it is not clear what buttons I refer to - please check the manual of your camera which will have a section on manual AF-points control.

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