Cannon Rebel Xsi is the Auto Focus an Issue Want to do a little picture taking and need the best camera for the buck, read a post that Auto Focus on the Rebel Xsi is not reliable. Can anyone share their experiences and recommendations....
asked by R. Miranda on November 28, 2008
These sorts of posts are usually the result of a common beginner's mistake with these cameras because full-auto mode uses all the auto-focus points at the same time. The camera picks the single focus point it thinks is best which isn't necessarily the one focused on your actual subject. To use auto-focus properly, the shooter needs to switch to P, AV, TV or M mode and manually select just one auto-focus point to use. If you read professional reviews or those written by experienced photographers, you won't hear anything about such auto-focus issues.
I own nearly all of Canon's digital SLR cameras, from the 10D, 20D, 30D, EOS D1s MKII and MKIII. I am a professional photographer. I personally cannot tell any difference between the autofocus speed or accuracy from the $600 camera to the $8000 camera because it is more dependent on two things: how fast (both in light gathering and autofocus motor speed) the lens is, and correctly selecting autofocus points. I shoot some college football action. Of course, I am spoiled with the wonderful DS1 MKIII. BUT, I use the fine Canon 70-200 IS f2.8 lens ($1700). When I bought a Rebel SI as a backup, I decided I would test it. So I shelved my high dollar Canon and shot 3 straight games with the Rebel. It blew my mind that the results were nearly equal. Yes, the 21 megapixel MK III give me much tighter cropping ability, but the newspapers I shot for never knew the difference. If you are using an f4.0 or 5.6 (cheap) lens, then the autofocus will perform poorly (indoor mainly) because the camera is struggling to get enough light to do the autofocus thing. Slap on a 1.8 or 2.8 lens, and you will be amazed at how much better autofocus works. The selective focus points are important. I sent a new photographer to a basketgame the other night. She left all the focus points turned on (13 of them, I think. It varies from model to model.) Well, if 9 of the points were over the crowd, and 4 of the points over the action, guess where the camera focused? Majority rule, you know. So, in sports, we usually go with the "rule of thirds" and turn a single point on. Then the photographer has to be alert enough to make certain that point is over the action. But then it works great.
As I said, I believe the vast majority of complaints about the Xsi's focusing system is based on a simple misunderstanding of how the camera's focusing system works.
But, in my own experinece, I have also found the XT's focusing system a bit too inaccurate with fast lenses and narrow DOFs, especially in lower light conditions. The XTi was a huge improvement in this area due to its added center f2.8 high-precision focus point (well worth the upgrade for me). So, yes, the Xsi definitely has a better focusing system than the XT's. If you're shooting as NLee does with a single focusing point and still having focusing issues, I think you'll find the Xsi a huge improvement with fast lenses (just avoid the XS in that case because it does NOT have the center f2.8 high-precision focus point).
Now there are also other possible issues with your XT. Lenses and the camera focusing system itself CAN be/become miscalibrated; components can go out of tolerance over time. I've had this happen with one dSLR and had to send it to Canon (more than once) to get it properly taken care of under warranty. I've also owned a number of lenses that didn't focus quite right -- again, I had these recalibrated under warranty. Without knowing more and running tests, it would be difficult to say if your XT auto-focus issue was due to a miscalibrated lens or camera or whether you were just asking too much of the XT's focusing system.
I have the XT and I never have problems with the auto-focus. But of course, I only shoot in single-point focusing mode and always use the "aim, half-press, recompose, shoot" technique. Why would any SLR user allow the camera to decide where to focus, anyway?
I had problems with contrast as well as focus. What I read recently is to use the DEP mode and the spot focus at the same time. This way, the camera will pick the best setting for the main subject, and the background/foreground to be in focus as well. Hope this helps.
I have a Rebel xt (older model) and the auto focus is terrible. I have had a number of different cameras and the auto focus on the xt is the worst I have ever seen. I have to use manual focus 90% of the time. I just ordered an XSi and hope they have fixed this problem. Discourage to hear about problems with the XSi too.