Did I get a bad copy of the 135mm f/2???

[Leorooster]

I just received my new 135 f/2 when I got home from work. I was so happy and try it out immediately. It appears that the AF is a little slow. I originally thought that there might not be enough light, but after a compared it to my 17-40mm, it's even slow than the 17-40mm. Is it possible that the 135 slower than the 17-40mm, or I just got a bad copy???

Also, I suspect that the AF is not as accurate as it should be, what is the best way to test it?

Any suggestions and inputs would be appreciated.

Thanks.

[drisley]

The AF on the 135L should be as fast, if not faster, than the 17-40L.
Also, the AF on the one I had was more accurate than on all of my other lenses.

[Maureen Souza]

I had to send mine in for a tune up...it wasn't focusing well when I first got it. Now it is very zippy!

[Henrik Ploug]

"Also, I suspect that the AF is not as accurate as it should be, what is the best way to test it?"

Find a brickwall and stand at an angle to the wall - say 45 degrees. Select the largest aperture (f2) and the center focus-point in the camera menu. Halfpres the shutter for autofocus until you hear the beep-sound. Fully press the shutter to take a picture.

Upload the picture in your favourite photoediting-program. Find the center of the picture and look at it at 100 %. See if it is the sharpest part of the picture. If not your lens or your camera has a problem with autofocus.

[Juan Zas]

To test any lens/camera for Focusing issues, follow the this link, it´s the best one (and I have used/tested 3 or 4 diffetrent test charts/procedures):

http://www.canon-dslr.com/Canon_Jan05/Canon_SLR_Focus_Test.htm

Good luck

[Dchemist]

I found with my 135 that it is easy to be misled when using wide aperatures. At F/2 and when the subject is close, the depth of acceptable focus is so shallow that the overall image is soft -- softer than you might expect. This took some time to get used to. I had no questions about the speed of autofocus.

[Leorooster]

Thanks all for your input, I will try to do some sort of testing as soon as I can.

[Leorooster]

I had to send mine in for a tune up...it wasn't focusing well when I first got it. Now it is very zippy!

Mareen - do you suggest that I send the lens back to Canon if there really is a problem?

Quite frankly, I would just return the lens if I could easily buy another one. However, I spent a few weeks to look for a dealer who had it on stock. Not everyone is carrying this lens unfortunately. Since I want to get my triple rebate, I think I just cannot afford waiting for another few weeks. Just painful :(

Thanks.