Rebel XTi & L Glass Problems ?

[Rmclain3]

I've been having problems with my Canon Rebel XTi and Canon 70-200 "L" glass combination. It seems that the camera has a front focus issue and the "L" glass has a cromatic abberation issue. I shoot mostly soccer and track pictures so focus is critical to me. I've bee noticing that many of my shots aren't sharp and the CA between the white lettering on the red shirt is excessive, IMHO, almost all of the time (especially on bright sunny days). Take a look at these links and see if you agree with me.

The first pic is a focus test using a Tamron 17-50mm f2.8 lens.

Focus Test:

Using a Tamron 17-50mm f2.8
Small: http://loungelizard.smugmug.com/photos/215433595-M.jpg Large: http://loungelizard.smugmug.com/photos/215433595-O.jpg

Using the Canon 70-200mm F2.8 "L" IS USM
Small: http://loungelizard.smugmug.com/photos/215433647-M.jpg
Large: http://loungelizard.smugmug.com/photos/215433647-O.jpg

Using the Canon 70-200mm F2.8 "L" IS USM
Small: http://loungelizard.smugmug.com/photos/215433686-M.jpg Large: http://loungelizard.smugmug.com/photos/215433686-O.jpg

CA Test:

Using the Tamron Lens
Small: http://loungelizard.smugmug.com/photos/215433632-M.jpg
Large: http://loungelizard.smugmug.com/photos/215433632-O.jpg

Using the Canon "L" glass
Small: http://loungelizard.smugmug.com/photos/215433588-M.jpg
Large: http://loungelizard.smugmug.com/photos/215433588-O.jpg

What I'd like to know is if you are seeing the same results I am. I see a front focus issue when you view the focus tests pics and a CA issue when you compare the Tamron to the Canon lens pics. All of the pics were taken at F2.8, Av mode, AWB, on a tripod with remote release.

I've already sent the camera body and lens back to Canon for evaluation along with pics of my tests and a detailed explanation.

Tell me what you think. I hope Canon can resolve this for me!

[mmcmurr]

Not sure if I see the problems you're talking about. When I look at the two side by side, the 70-200 looks far sharper, in perfect focus and I don't see the CA.

[Rmclain3]

When looking at the CA issue photos, concentrate on the white lettering on the red jersey. If you zoom in a bit you should see that the white lettering seems to "bleed" into the red.

[Riff Raff]

I didn't really notice either problem you were talking about.

[mmcmurr]

After looking again, I can see that the focus looks soft on the white lettering on the 70-200 L shot, but it doesn't look like CA to me. It just looks soft. The tamron shot is sharp as a tack. But comparing these two different shots can be misleading.

Looking at the 70-200 L shot, her shirt is bunched quite a bit around the lettering. With the thin DoF of 2.8 it's gonna be difficult to get everything sharp as a tack.

If someone else see's something other than me, please speak up. My eyes are on the downslope so I definitely can't be deemed an expert!

[Gateruner]

I have looked at your shots and to me the 70-200 looks soft. My thoughts are the focus isnt exact on and you arent getting the crisp distiction between the letter/stripes and the red. I dont see any color changes, just not a sharp focus which makes it look like it is bleeding. Here is one more thing to consider. I looked at your EXIF data and you shot one at 34mm and one at 70. My understanding of zooms is they will get sharper as they move away from their lowest focal length. So the 2 shots might be a little different since you are at the minimum with the 70-200 and you are at a midpoint with the 17-50. Lens have sweet spots where they will give you the sharpest photo. You probably are closer to that with the 34mm and not there with the 70mm shot. After hearing what you are saying I would be more inclined to think this might be a focus issue and once you get a sharp image in camera you arent going to see as much of the bleeding.

I sent you a shot to look at and see if you think it is any different. Let me know what you see and I will be interested in hearing what Canon says about your gear.

Scott

[Rmclain3]

Bump...............

[Rmclain3]

Well, the camera body is back from Canon and the focus issue is resolved !!

[jtraub]

What was the issue?

[Rmclain3]

They never stated anything except that the repairs that I requested had been completed. I had requested that a front focus issue be addressed and repaired. The focus is spot-on now!