I recently purchased a used Rebel 200d. I planned to use an EF-S 17-85 lens on it. When I mount this lens, I cannot get a sharp focus. Same thing with my EF 20-35 lens. Has anyone else run into this problem, or am I doing something wrong, or does the camera require servicing? Admittedly, this is a new camera for me. Thanks very much.
"When I mount this lens, I cannot get a sharp focus."
What do you mean by sharp focus? Do you mean the pictures are not sharp or the viewfinder is not sharp? If the VF is not sharp the diopter may be off. Adjust it. Small wheel beside it.
If the photos are not sharp u/l a sample so I can see what might be the problem.
I've tried fiddling with the diopter dial, with no success/change in the unsharp photos. The AI option seems to work, but using this exclusively turns the camera into a large point-and-shoot camera only. I normally use Aperture priority. I am wondering if it is the lens which may need adjustment, replacing it with an STM lens, or formatting a new card. My last option...I'm doing something real stupid and don't know it.... Thanks for your advice.
AI Servo has its place if you are trying to follow a moving subject.
What you shouldn’t use is AI Focus mode. It is supposed to switch between One Shot and AI Servo depending on whether the subject moves. What frequently happens is that the user moves the camera and the caythinks its subject movement.
"...my never using the AI Servo format. I only use "One Shot.""
Never say never. It has its place but I always tell my classes to not use Ai-Servo until they completely understand how their camera works. Obviously you are not there yet but you will be if you try to and continue to learn photography. This also applies to the less automatic modes like Av. They require some photographic knowledge before employing.
"...but this one is a somewhat different breed..."
The controls and/or modes may be different but photography is still photography. Does the FTB in your handle refer to the Canon FTb film camera? Great camera, BTW. Yes, the controls will be different from it.
Start with general stuff with good light and set the SL2 to P mode, ISO 200, and the lens in AF. Take some shots and check them out. You will quickly learn how the SL2 operates. Then you can try the less automatic modes like Av and Tv, etc. You'll see it really isn't all that different than your FTb. Just the way it works. Show some samples, u/l here, as you progress. I'd like to see them.