Quote Originally Posted by HDNitehawk View Post
ashmadux

If you use the method Sean describes you will be able to tell if the lens is sharp or not. I think you will find that the lens is sharp using this method.

Your logic that your rebel body is not the problem is not sound. No doubt the camera may perform flawlessly with other lenses, but that doesn't mean it will play nice with all lenses. Bodies seem to vary from one to the other in how they interact with certain lenses.

When I bought my 70-200mm I set up tests to check it. After several thousand test pictures using the lensalign pro, on my 5D II, 1D IV and 7D I found something out. The 70-200mm has a focus curve from one end of the rage (70mm) to the long end (200mm). It will front focus slightly at 70mm and back focus slightly at 200mm. The lenses focus falls within the acceptable area through the whole range. This phenomena was hardly noticeable when using the 5D II, using the crop bodies it became more noticeable.

Even if your new 70-200mm passes Seans test for sharpness, it will not correct your problems. If you are not getting sharp focus using AF you have three options (2 in the case of the rebel), Do an AF Microadjustment, send the lens and bodies to Canon and have them do an adjustment or send the lens back for another copy and hope it plays well with all your camera bodies.

Spot on (no pun intended)

After performing an initial test and comparing images side 2 side (MF/AF) its just like you said- sharper in MF- the AF is producing a softer picture throughout the zoom range- though the lens seems soft at 200 mm using either AF method. Personally, I dont want to have to deal with glass that is inconsistent from body to body, as impractical as that may sound.

Ill try the MA tonight and see how that goes, but its leaning towards the AF not producing the best it can. Ah well, it will likely go back to the shop tomorrow. Crossing my fingers for a second version.