Sony A100 focusing

I have a Sony A100 DSLR and its focus is terrible in less-than-ideal
conditions. In dim light (not even t-h-a-t dark), the flash flashes
several times and takes several seconds to focus before the picture is
taken.

There is an indicator that comes on when the picture is in focus.
Often times, the image appears to be in focus through the viewfinder
but the focus indicator doesn't come on. If the focus indicator does
not come on, the camera refuses to take the picture.

This problem doesn't only happen in low light. I was on a plane ride
and trying to take pictures of the ground. It was a cloudy day, but
not too bad. Often times, the camera would not be able to focus on the
ground, and refuse to take the picture.

I have a small point-and-shoot digital camera that focuses better than
this camera. Is this just a problem with my specific camera, or is the
Sony A100 just bad at focusing?

On 21 Dec 2006 20:06:27 -0800, jeffrey wrote:

> I have a Sony A100 DSLR and its focus is terrible in less-than-ideal
> conditions. In dim light (not even t-h-a-t dark), the flash flashes
> several times and takes several seconds to focus before the picture is
> taken.
>
> There is an indicator that comes on when the picture is in focus.
> Often times, the image appears to be in focus through the viewfinder
> but the focus indicator doesn't come on. If the focus indicator does
> not come on, the camera refuses to take the picture.
>
> This problem doesn't only happen in low light. I was on a plane ride
> and trying to take pictures of the ground. It was a cloudy day, but
> not too bad. Often times, the camera would not be able to focus on the
> ground, and refuse to take the picture.
>
> I have a small point-and-shoot digital camera that focuses better than
> this camera. Is this just a problem with my specific camera, or is the
> Sony A100 just bad at focusing?

I can only guess, and mine would be that the problem is not just
with your specific camera. The A100 is based in part on Konica /
Minolta designs, and their camera's AF performance often had
problems. The A2 and A200 frequently misfocused, but unlike your
A100, the focus indicator would come on when the camera was not
accurately focused.

Does your A100 manual describe the types of subjects help the AF
system to focus as well as those that cause focusing problems? My
manuals describe several, and subjects with well defined vertical or
horizontal lines generally work well. You should try to avoid
trying to focus on fur, smoke, very low contrast objects, etc.

The AF assist you get from the flash obviously will only work for
focusing on fairly close subjects. When trying to focus on the
ground (while riding in a plane), you'd still want to try to
prefocus on some suitable focusing subject and then after getting a
good focus indication, reposition the camera to frame your intended
subject. Vibration while flying probably makes focusing a bit more
difficult. Your manual may not provide detailed information on the
alternate photography modes, but as implemented by some
manufacturers, some, such as "landscape" mode may prefocus to near
infinity. If the A100 does this you might try using landscape mode
to take pictures on the ground while flying. Other cameras offer
Custom modes where you can preset many options including the
focusing distance, which may be easier to use than trying to
manually focus while flying. Did you try using manual focus?