This is a repost to my earlier question: problem with camera focus.?

Question

I was just recently given a Canon EOS Rebel XS, without a lense or manual; just the body. Surprisingly I found two lenses (for 3 dollars!) that fit perfectly, but if I am using the automatic focus, on both, the shot still looks out of focus when the camera says it is set. I thought I could fix this problem by manually focusing my shots. When I had my first roll of film developed, however, every shot was out of focus. The thought occurred to me that although the shot may be out of focus when I use the automatic feature, the shot may be perfectly focused on film. I have yet to see if that theory is true or not, but I'd like to find a way to fix this AF problem, and not have to continue to hope that every shot turns out!

Both lenses are Quantaray-CNs: 28~70mm & 70~210mm equipted with AF, obviously. They have been tested on another film camera and they work fine, so the problem isn't within the lenses. I have searched for the manual online and elsewhere and have come up unsuccessfull.

Answer 1

The Quantaray lenses that you have may have newer chips (circuitry) in them and may not play well with the older Xs (not to be confused with the XS that's not out yet).

The Xs has center focus only, make sure that your focussing on the center and then recomposing if you want the focus point to be somewhere else.

My Xs (and XTi) backfocus on my 50mm lens, but that lens works just fine on my 40D. The issue may be with the communication of the lens and not the lens itself. Try cleaning the contacts with a pencil eraser.

Try stopping down a bit, if you stop down to f/11 and everythings still out of focus then you definately have a problem and you will want to either get it fixed, or find another camera as the repair may be expensive. Canon will look at the camera and not charge you unless you authorize the repair.

Try a Canon lens on your camera. You may just have gotten what you paid for with the $3 lenses.

Make certain that the AF is indeed turned on and focussing. I know you already said you did that but I just have to cover my bases. Make sure that the switch on the lens is set to AF and not MF.