40D Focus Problem

[schent1]

I have spent the last few days trying to figure out if I have a focus problem and have discovered the problem is with my 40D body. I brought home a Rebel from work and did some comparison shots using the same lens on each camera. The Rebel was clearly sharper than my 40D. I took it to the camera store where I purchased the camera and they repeated the test and had similar results. They are sending the body back to Canon for repairs. Fortunately the camera is still under warranty.

I know that I need to learn more and improve technique but having a camera that focus correctly has got to make a difference. I just wish I had figured this out 8 months ago when I got the camera.

When the camera comes back should I expect the Rebel and 40d to produce equal results or should the 40D produce better results?

[TCav]

Originally Posted by schent1

When the camera comes back should I expect the Rebel and 40d to produce equal results or should the 40D produce better results?

That depends on what you mean by "better".

The biggest contributor to image quality is the lens, so using the same lens on each body will produce similar results. The 40D is a 10MP camera, while the original Rebel was only 6MP, so that should make the 40D perform better (if that's the Rebel your talking about.)

Testing two cameras with the same lens under conditions designed to attentuate flaws will simply produce similar results if the two cameras are both performing optimally. (... or equally poorly.)

[schent1]

Thanks TCav.

The Rebel I borrowed from work to do the compare was a Rebel XS. The loaner the store gave me is a Rebel XSi. I can already see an improvement with the XSI over my 40D that got sent back.

I guess the question I am asking is how to know if the camera is really fixed and performing correctly when I get it back? Is it same to assume that it will be functioning correctly when it comes back?

[TCav]

It's safe to assume that the camera will have been perfoming within the manufacturer's specifications once it leaves the technician's workbench. What happens between there and your hands is anybody's guess, but it's reasonable to assume that it will be ok.

You performed some objective tests to determine that there was a problem, and the store you purchased it from confirmed your results. Surely, Canon would have performed similar tests, gotten similar results, and fixed it. When you get it back, test it again. I recently had a situation where I sent my camera in for warranty work. It was repaired, but when I got it back, it had another, unrelated problem. Be very thorough when you test the camera. Don't just test for the problem you sent it in for.

[schent1]

Tcav,

Thanks again for you input. I did some searches on line on how to test out a camera and am not coming up with much.

I suppose one method would be to step through the camera manual and try out all the functions to insure everything works. The added benefit here is it’s a great opportunity to learn the camera better. The only issue here is being new at digital photography and not necessarily know if some if performing as expect. With the focus I did not know what to expect and assumed I was the cause of the focus problems, now I know it was not totally at fault.

Do you have a strategy you use to test out a new camera?

Thanks again

Tom

[TCav]

Originally Posted by schent1

Do you have a strategy you use to test out a new camera?

Use it.

... a lot!

The stuff that's likely to fail in shipping are the delicate things. Make sure all the controls and buttons work. Make sure the covers are secure. Try every lens you have. Autofocus it from near to far and back. set the aperture via the camera, and use the DoF Preview to confirm the setting. If you have a flash, try it. If you're flash zooms, zoom the lens and see if the flash zooms too.

[schent1]

TCav,

Thanks so much for your help!

Tom