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Old Oct 20, 2008, 4:41 PM   #1
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I just bought new EOS Rebel XSi kit with the 18 - 55 mm lens. I've got serious focusing problems, and I already have exchanged this camera three times. The auto focusing problem persists in other ones as well. Let's forget about all kind of tricks some users recommend (turn off Live view function, change focusing points set up, put camera on tripod, etc) and put it this way: If you use wide angle set up for 18 mm, set full automatic mode in a sunny day landscape, 1/125 and aperture 11, keep camera still, you should'n be expecting any focusing problems. But the picture looks like if somebody set by the mistake macro mode and was trying to take landscape. Everything is blurry. By the way I tried all recommended solutions and none of them works. All three cameras produce exactly the same focusing problems

I was taking pictures in all modes: Fully automatic, Landscape, P. I'm using optical viewfinder and I canobserve adjusting process, but the picture I receive on card is of focus, see attached picture

It seems to me I hit dead end, I don't think it makes sense to come back to the store and exchange the camera for the 4-th time. The first one I purchased at the Future Shop on line and another two in two different Future S. locations.

Does any body knows, how to resolve this problem?
:?



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Old Oct 20, 2008, 10:04 PM   #2
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Out of curiosity, did you use the same lens for all three camera bodies?Sometimes the problem isn't the camera, its a faulty lens. Its hard to tell from your picture if that's the case or not. It would be my first thought, since you've tried 3 different cameras. Have you tried manual focus? Did you get a sharp picture that way?

Thecameracan havea problem with back or front focusing (it focus in front of the focus point). Have you tried to shoot focus charts to see if you have any point that's in focus/sharper than any other part? Make sure the camera is set to use only the center focus point for this - you can get false readings if you let the camera choose the focus point. This wouldn't be my first thought since you've had problems with more than one camera body.

Hopefully someone who is familiar with Canon will have better ideas (I shoot Pentax, so am not familiar with your specific camera). I hope someone who is familiar with the lens you are using can address whether the vignetting is normal for that lens - it almost looks like the lens hood isn't mounted quite right (did that when I first got a wide angle lens). Also, it's not unusual for a zoomlens to be soft at it's extremes but I wouldn't expect it to be THAT soft. But I'm not familiar with Canon lenses.
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Old Oct 21, 2008, 1:56 AM   #3
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Firstly mtgal is right - is this all with different lenses, or all using the same lens? Because the vignetting looks pretty severe, but uneven as though the lens is horribly decentered.

Secondly, you're not using some cruddy UV filter are you? That could also cause the vignetting we're seeing, and if it's a cheap one might be well and truly messing up your pictures. If you are using a filter please take it off and try again.
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Old Oct 21, 2008, 6:29 AM   #4
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According to tne Makernotes metadata in the image header, no focus points were being used for that shot. Are you sure don't have the AF/MF switch on the lens set to the MF (Manual Focus) position?

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Old Oct 21, 2008, 7:34 AM   #5
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It's also possible that you are using AI Servo mode - i.e. fpspriority. In AI Servo the camera will take a picture regardless of whether it gets a focus lock or not.

Switch to "one-shot" AF mode and try again, in one-shot mode the camera will not trip the shutter until it gets a focus lock.

AI Servo mode is best for moving subjects, not static ones.
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Old Oct 21, 2008, 9:59 AM   #6
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First – thank you to everybody for trying to help me.
Here are the answers for all additional questions you asked me.
The body comes with the lens and every time I exchange the camera it comes with its own lens in one box. So there is no issue of one defected lens. The vignetting was caused by UV filter. In another two cameras I was taking pictures without any filters. Furthermore I can watch all process of automatic focusing. After I press the shutter half way, I can see focusing ring adjusting the focus. While watching through the optical viewfinder I can see the image moving from blurry to sharp. Ones it reaches the right point I press the shutter all the way. So far everything looks perfect. The surprise comes when I come back home and download pictures to PC. ALL (around 100) of them show the same problem. I was trying different modes: fully automatic, automatic landscape, aperture or speed priority, center or multiple focusing points. The switch is in AF position. I was using One shot and A1focus positions. No difference.
I read in dpreview.com comment, that this camera produces crisp pictures. I'm afraid it's not my case. I spoke with Cannon tech. support staff and emailed them the sample picture. They promised me an answer within 24 hrs. I'll notify you about the results
Thx, George
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Old Oct 21, 2008, 11:20 AM   #7
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You can't really judge Autofocus Accuracy by what you're seeing in the viewfinder. Modern dSLR models don't have the same type of split prism focus screen found in older cameras that used manual focus lenses. In addition, the viewfinder is a bit smaller on this type of camera, mostly due to the smaller APS-C size sensor.

If you're using Autofocus, be aware of what it's actually focusing on (which focus point(s) turned green with a half press). Most Auto modes for focus (wide area, etc.) are designed to focus on something closer to the camera by default (and it probably locked on something closer to the camera, if it even locked, since the makernotes seem to indicate it didn't have any focus points selected).

My suggestion would be to select your focus point, or set it to center focus for those types of shots (making sure you're not focusing on something like brush or shrubbery that's closer to the camera, which may have happened in your example). That way, you don't end up with images that let the camera decide what to focus on (which may be something closer versus further away).

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Old Oct 21, 2008, 11:35 AM   #8
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I took more than hundred pictures of different objects and using one and nine focusing points. I was taking remote landscapes without foreground. I think that with 18 mm equivalent wide angle in a sunny day the depth-of-field should reach big range and practically every picture should be well focused.
I'm still waiting for an answer from Canon tech.support
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Old Oct 21, 2008, 11:38 AM   #9
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Just wondering, do you use a tripod and if so, do you turn the IS off? If not, that is very often the cause for blurry pictures.

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Old Oct 21, 2008, 12:09 PM   #10
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No I wasn't using tripod and IS was in On position
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