More surprises after the trip to canon, the LCD screen suddenly turned blue and the camera hang while I was viewing some picture. I hope that canon didnt spoil anything after the cleaning.
I also complained to Canon about the focusing problem that I encountered. At first I didnt realised that the camera back focus until almost every pic I took are out of focus. When I shoot with a tele at wide open, due to the shallow DOF, the effect is the most obvious.
He also tested the focusing for me and found that indeed there is a slight back focusing, they were using some test charts to do the testing and I wasnt sure of the lens/setting or procedures he used. Anyway, the conclusion is that the back focusing problem is still acceptable".
So I decided to do more tests to show them.
The camera was mounted on a tripod, with cable release and mirror lockup enabled. The test objects are shown in the pic above, the box, heatsink and the piece of paper are all inline and parallel to the camera which is about 2m away. The paper was folded backward after the black vertical line. The camera was set to ISO 100, one shot AF mode, with a 550EX mounted and pointed at the ceiling. The flash AF assist lamp was used to ensure that the AF is as accurate as possible. Lens used were 50mm/f1.8 and 70-200L f2.8 @ 200mm. Only center focus point was used and the pictures were taken at Av mode with aperture at wide open.
Firstly, I turn the focusing distance to minimum, then half press to AF on the center of the blue box. The above picture was cropped and resized, the original pic without resize is here
http://kamwai.clubsnap.org/10D/focus-01.jpg
Next, I turn the focusing distance to infinity, then half press to AF on the center of the blue box. The above picture was cropped and resized, the original pic without resize is here
http://kamwai.clubsnap.org/10D/focus-02.jpg
Lastly, the above shot was taken using manual focus. It was cropped and resized, the original pic without resize is here
http://kamwai.clubsnap.org/10D/focus-03.jpg
As you can see, the focusing problem seems to be even worse when focusing from minimum (ie. the first pic)