Canon 20D focus calibration and exposure questions

I've really been having bad luck with EOS equipment lately. I posted earlier

about having a 70-200mm f/4L with a blurry left side (which I will be taking to

my local service center soon), but something else has come up. I recently

switched sold my trusty Rebel XT to upgrade to a 20D, only to find that the 20D

consistently focuses in back of the subject. I ran a test with a ruler and the

camera on a tripod with mirror lock-up in order to confirm this. I will be

taking the 20D up to the Canon Irvine Service Center to have it recalibrated at

the same time as the 70-200mm f/4L. I have a 50mm f/1.8 II that was tack sharp

with the Rebel XT, but now will not give a sharp picture with the 20D.

Surprisingly, my 17-85mm IS works just fine on the 20D body, as it did on the

Rebel XT.

My question is, if the lenses that I had before worked perfectly with my Rebel

XT, do I need to send them in to be recalibrated too? Will simply recalibrating

the 20D fix the problem? Also, have any of you noticed any exposure problems

with your 20Ds? I keep thinking that the colors and exposure were less washed

out and more smooth with my former Rebel XT compared to my current 20D, which

seems to give colder, slightly overexposed colors - is this proven, or is it

just me? How would I correct this in camera (without resorting to unnecessary

Photoshop manipulation that I didn't have to do as much when I owned the XT)?

Thanks again for all your help!

Sorry to hear you are encountering such a spate of problems.

It has been generally documented, even from Canon, that they calibrate the camera separately from the lens. To calibrate the camera they have a known good lens (a 50mm F1.4 if memory serves). Likewise for the lens they have a know good camera. This is done to prevent both being calibrated to one another such they they will not work with any other body or lens. That said, if you send in both they will them test that your camera works for your lens. So I think it best you send in both camera and lens - this is what Canon recommends

The results you see with your camera lens combo are not unusual. The 50mm F1.8 is notorious for working well on some bodies and not on others. It is reputed to do well on the 40D for example where the exact same lens may not have performed well on the 30D. Om my 20D it is not consistent at all. The 17-85mm is a known quantity and appears to work well on almost all 1.6x bodies. This lens was released with the 20D and probably has some kind of "adapting" technology. The 50mm on the other hand was released before these cameras even existed.

The 20D does take washed out shots. The 30D takes more saturated shots and the 40D even more still. The XT series has always been more saturated again. You need to amp up the setting if you are in JPEG and for RAW you will need more adjustment than your Rebel. I think this is a matter of getting used to the camera. It does take fantastic shots.

These are my experiences. Like you, I have the 20D, 50mm F1.8 and the 17-85mm. I had the 70-200mm F4 for a long time but sold it for the 70-300mm IS

Good luck with your repairs, they will work, Irvine has a very good reputation. Please let us know how your get on.

I compared my 20D with a friend's 20D today, and was shocked to find that my 70-200mm f/4L misfocused with both cameras! At the same time, his 200mm f/2.8L focused perfectly with my 20D. So, it looks like the 20D is not at fault.

I'm finding it really strange now that the 70-200mm f/4L would work so much better with the Rebel XT, and be terribly off with the 20D bodies. The 50mm isn't as bad, but it's not as great on the 20D bodies as it was on the Rebel XT - I'm just going to chalk that up to the variation in the 50mm that Peter talked about. How could the 70-200mm f/4L vary so greatly?

The 20D is rather well know for having flaky focusing. Backfocusing in particular. Do a search on this topic on this forum. Basically, the focus points are larger than what is shown on the screen, so you can snag backgrounds, and even foregrounds rather easily. Plus, the 20D has a tendency to just flake out occcasionally, and to change focus even when it isn't supposed to. It helps to keep focus on One Shot and put the focus to the * button (CF 4), and to focus twice on a contrasty point. The tendency is worse with wide angles. You just get to know what kinds of situations will cause the camera to fail on focus. Manual focus is also an option.

Then there is the whole other issue of focus with particular lenses. Also the XT is newer than the 20D (?). Since the 20D, focus in general has improved.

I've had a 20D for approx five years. You can't compare it w/ current models. Still, if you fish around in the settings, you can compensate for color shifts and contrast problems. Like mountain bikes, 99% will never see mud, so use the manual settings. The 20D has tons of adjustments that can tweak the camera's stock settings to do a decent job with whatever you're shooting. Try using the white balance shift/bracket settings to add some warmth to otherwise cold shots. Take standard shots against a gray card in different light settings and learn how your particular model behaves. They're all different, even the same model. I'm just starting to be satisfied with my 5-yr-old 20D! Almost all of my stuff on flickr is with this camera, save for some old shots. Look up johnadowney2.

Cheers and happy trails.

John<div></div>