Question for DK about focussing

[RubberDials]

David,

I used my A350 to cover the Goodwood Revival for a website two weeks ago and had a couple of unpleasant surprises. The first was the camera getting knocked onto ISO 3200 for about twenty five shots. Don't ask me how this happened but it did, the second was the number of focus errors I got. By this I mean the camera confirming focus when the subject is not in focus - I don't mean back/front focus. I think this only happened to me once on the A100.

Does the A350 have fewer focussing steps/coarser parameters, because it is a 'consumer/beginner's' camera? Have you had similar problems? I don't really hear many complaints about the focussing accuracy of this camera around and about, although I note that the some of the test images on the Imaging Resource website are out of focus. It's cost me a fair few images now and I'm heartily sick of it.

Incidentally, although the Revival is a motorsport event, I wasn't tracking racing cars with a long lens - I was shooting people with the 16-80 and centre AF.

Rob

[RubberDials]

Obviously, although I am interested in David's take on this, I didn't mean to exclude anyone from the discussion. Should I put the hammer down and put the A350 back in the bag?

[David Kilpatrick]

Which lens? I find that the SAL 70-300mm SSM will refuse to refocus some of the time, and produce OOF shots, on all the camera bodies. I've had the same issue with long lenses generally when there are certain types of subject, usually with vertical stripes or patterns. I have not tried motor track shots, but my A350 focused reliably with the 70-300mm Tamron during the week I spent shooting with this body only earlier this year. The menu items include AF priority or release priority, and I assume you have set AF priority (the default) because if you do not, the shutter will fire when AF is not confirmed. I also have found using focus range limiters, where fitted, useful for improving the speed and success rate of tele shots.

But, beyond this, I have not found the A350 to be worse than the A100 or A200 for focusing errors.

David

[lock]

David,

I used my A350 to cover the Goodwood Revival for a website two weeks ago and had a couple of unpleasant surprises. The first was the camera getting knocked onto ISO 3200 for about twenty five shots....
By this I mean the camera confirming focus when the subject is not in focus - I don't mean back/front focus. I think this only happened to me once on the A100.
Rob

About the iso 3200, you probably accidently hit the iso button. Also, the 350 has a default auto iso range of 100-400 ( though I'm not sure whast the range is in sports mode), so that could not be the problem I guess.
About the focussing problem, did you open up the lens maximally ? Are you sure in the back/foreground nothing is sharp ? It may not be structural FF/BF, but because of the dim light some objects with more contrast than the one targeted, could force the camera to pick something else to focus on.

[RubberDials]

Thanks David.

I was using the 16-80 exclusively. The only other lens I use is the 100-300APO which is definitely better, but still does it. For the short time that I had the 70-300G I experienced exactly the problem you describe - refusal to refocus - but I've also had this with the APO.

The assignment was for a vintage clothing website, so no cars! Release priority was off.

You mentioned the A200/A100 but not the A700 - does that mean that the focussing is more consistently accurate on this body? You said in an earlier piece that the focussing of the A350 was 'just good enough' - I took this to mean that the camera designers had prioritised speed over accuracy, as it was aimed at the consumer rather than the amateur photographer market. Is that right? Am I asking too much of it? I've tried an A900 and the focussing seems to be all I want (and a lot more besides), but I can't afford it. The A700 on the other hand is reachable.

Rob

[David Kilpatrick]

Yes, the A700 is better - as you would expect it to be. Also, the better viewfinder means you can almost see when it is making focus errors!

David

[RubberDials]

Okay, thanks.

Anyone want to buy an A350?