Hi,
My new 70D has the dreaded focusing problem regarding the centre focus point, the photos are so soft that the camera is unusable & the micro adjust makes no difference.
so in it goes for repair under warranty my first ever canon camera with a fault,
i will be back to let you all know what they do to solve the problem.
Darren
You are lucky. My experience with Canon's AF systems is nothing short of a horror story.
When I got my 350D, it had a front focus problem, the Canon Service Center in Willich, Germany, did not solve it properly, I sent the camera ago them TWICE, then I managed to solve it myself using the procedure described here:
http://www.astrosurf.com/buil/autofocus/adjust.htm
My 40D was also sent to Canon twice, the first time alone, the second time with all my lenses. After this, they would all focus perfectly with the camera and with the old 350D. I brought the equipment myself to Willich to explain to the technicians, with plenty of test pictures. They finally understood what was going on and they fixed it. They calibrated both the camera and lenses to their test equipment at my request - instead of trying to match. And this worked!
And then I bought the 70D. Problems with the center AF noticed only recently because I tried the Sigma 18-35 f/1.8, that worked fine (not perfectly, but fine) on the 40D. Focussing great with all points, except the central one - which is the one I use most.
With the Canon 50mm f/1.8 II it is the same story: the camera cannot focus at all with the center point, but is astonishingly precise with the other 18 points. I tested also my old 40D with that: all points focus precisely
The little Sigma 30mm f/1.4 worked decently on both (but it hunts endlessly with the OSPDFA, well: I do not care - it is an old lens with known problems, I have one of the few exemplars that is actually reliable).
Interestingly, my 70D focuses well with the 50mm f/1.2 L and the 85, f/1.2 as well, but the lenses have also a much larger image circle other than the even larger aperture, so maybe it is a combination of image circle and aperture that determines critical angles for the light to hit the "extra precise at f/2.8" AF sensor, and then throws it off. LOL. If this is the case...
It seems thus that a misadjustment of the diagonal cross in the middle (the center point is actually 2 superimposed points, a normal "+" cross and an additional "x" cross that is extra sensitive and increases precision at f/2.8 and faster) is particularly critical at some apertures, in my case f/1.8 (since focusing is always done at max aperture, the aperture value that counts is the max at the given focal length you are using). When the "+" and "x" parts are not properly calibrated with each other, then the camera can focus badly. Also, this amplifies miscalibration problems of the lens.
Indeed, I could almost get the Sigma 18-35 to work reliably, playing a lot with the sigma USB dock, but of course this made the lens unusable on other cameras, and the other focus points tended to focus reliably, but in a unpredictable way, on objects that are around the target, usually behind, as if the camera was now prioritising objects "near" the AF square (it is very well known that the sensitive area is much larger than the squares in the VF) that were behind my objects - and focussing PERFECTLY on them and always on the same ones.
Because of this, just today, I sent my 70D for the
third time to Canon. Yes THIRD time: apart from this newly discovered problem, there is the fact that the wheel on the back is badly mounted and "tilts", a thing canon has ignored so far, and the thumb rest is moving under the thumb when the camera is warm, something Canon fixed twice by tightening some screws, apparently, and/or replacing the cheap rubber faux leather on the thumb rest, but after a couple of months this disturbing problem returned.
The handler told me that it there are any further problems, then by German consumer protection laws I have the right of getting a replacement, and they would comply immediately. I hope the replacement works. The handler confirmed that they had to send a ton of 70Ds back to Canon for various combinations of these problems.
The camera can easily be a lemon. There are massive quality control problems, and the tolerances at which it is built are orders of magnitude more relaxed than the old 40D. They are not even in the same class. Do not trust anyone that claims it is a well built camera: they live in a delusion, just because they were lucky, or are using only slow glass. Do not buy a used car from people that deny the 70D has problems ;-) This camera is not a worthy successor to the 40D. It is built worse than my old rebel.
Now, picture quality and features, when the camera works with your lenses, are light years ahead of the 40D, and it even surpasses the 7D a bit in the field of "quality" of the noise (the noise levels are just a bit better, but they are much more easily processable that it sometimes seems it has a one stop advantage), but I would never recommend it to anybody. As soon as the 7D's successor is out, I will wait a bit, then as problem settle I will dump the 70D on ebay and try to forget such a nightmare ever existed.
Roberto
