Why 10D autofocusing seems to fail

[lightandlife]

Now I have a hunch why some people seem to experience autofocusing problem with 10D.

If any picture you shot does not have a sharp focus, use your Canon viewing utility that came with 10D and view that particular shot. It not only shows you the picture but also where the focuses were. The picture should be sharp in the focus area, if not in other areas.

If you want a sharply focused picture at a single point, you should choose a single focus (such as the center). Neither horizontal nor vertical nor 7 point focusing option can figure out which of the 3 or 7 points you have in mind. (Have you heard of a mind-reading software?) So it chooses the focus for you for each shot, and that choice may not be what you wanted. In my case, the camera was not able to read my mind most of the time.

If this happens, choose the central focusing point. This should eliminate the focusing problem. With central focusing, compare your shots between auto and manual focus shots. If the former is inferior to the latter significantly, then you really have a focusing problem.

I am happy with 10D, because it can take pictures that were impossible with D30.

Let us give a big applause to the researchers who spent untold hours to develop this camera! I wish I could show you a shot now, but I am traveling at the moment.

lightandlife

[k_s_rajeev]

I would like to see the difference between the 30d
and the 10D.

Thank you.

[lightandlife]

k_s

I would like to show you the difference between D30 and 10D, using two photos stored in my temporary local drive. But this seems to be infeasible. If anybody knows how to, I would like to be enlightened. This embedding method seems to hijack images online, rather than take images from a local drive.

I will make one correction.
When two or more focus points are chosen automatically by 10D, the actual focusing distance seems to be a weighted average. In other words, when two focusing points are used, images at neither points may be sharp, but it will be sharp at a unique focusing distance, which is somewhere between the two.

10D's autofocusing is far better in low light conditions. I was able to take night harbor scenes of Hong Kong (handhold), which was difficult to do with D30.

[sjprg]

www.pbase.com gives you 10 Meg of free image web space or $23.00 a year for 100Meg.
Paul

[lightandlife]

sjprg wrote:
www.pbase.com gives you 10 Meg of free image web space or $23.00 a year for 100Meg.
Paul

Thanks, Paul.
I did not understand the procedure well, but I barely managed to upload two shots, one from 10D (Aug 2003) and the other from D30 (2001) from the bird market in Hong Kong. They are at http://www.pbase.com/lightandlife/inbox

The second photo was shot with D30 and 28-70mm L, and I was happy with it at the time. The first was shot with 10D and 35mm 1.4L when I used multiple focusing. There were 3 focusing points. One was eliminated from cropping. From Canon viewing utility, I discovered that 10D chose two other focusing points, the eyes of two birds looking at you. The actual focusing distance was, I think, a geometric average of distances to the three focusing points, and hence this was not sharp from any single focusing point.

But what did it matter? I am happy with the shot and 10D. Other shots with multiple focusing were not satisfactory. 10D simply could not figure out which focusing point I had in mind. I have since switched to central focusing.

[PacAce]

lightandlife wrote:
Now I have a hunch why some people seem to experience autofocusing problem with 10D.

If any picture you shot does not have a sharp focus, use your Canon viewing utility that came with 10D and view that particular shot. It not only shows you the picture but also where the focuses were. The picture should be sharp in the focus area, if not in other areas.

If you want a sharply focused picture at a single point, you should choose a single focus (such as the center). Neither horizontal nor vertical nor 7 point focusing option can figure out which of the 3 or 7 points you have in mind. (Have you heard of a mind-reading software?) So it chooses the focus for you for each shot, and that choice may not be what you wanted. In my case, the camera was not able to read my mind most of the time.

If this happens, choose the central focusing point. This should eliminate the focusing problem. With central focusing, compare your shots between auto and manual focus shots. If the former is inferior to the latter significantly, then you really have a focusing problem.

I am happy with 10D, because it can take pictures that were impossible with D30.

Let us give a big applause to the researchers who spent untold hours to develop this camera! I wish I could show you a shot now, but I am traveling at the moment.

lightandlife



Actually, you can't rely on the focus point indicator (the red box) to tell you what you focused on. It only tells you which focus point you used. The reason it doesn't necessarily tell you where you focused is because it is very possible that you focused and then recomposed your picture at which point the point of focus will be outside the focus point.