Lens Calibration

I have read quite a few questions that people have had about their lenses whether or not they should keep

them or get new ones because they aren?t sharp. There will usually be a response that says that they got

their lens calibrated for the body they are using. What is this? And is it worth it? And what does it usually

cost? And how long does it usually take? I have a canon 30d. I have Canon 28-135,100mm macro,

100-400. Can these be calibrated?

are you happy with the setup you've got? It's free if under warranty, have to send it to the Canon repair facility, takes about a week to 10 days. I just sent the lens alone for calibration 70-200 f4/L and it performs the same after "focus and tilt were adjusted". The problem was a slight backfocusing, BTW this is on 30D. I know the lens is sharp, I suspect it is the combo that need to be calibrated.

Your lenses and camera can all be calibrated. However, it's only worth worrying about if your images show focus problems. If they do, you should conduct focus tests with the camera on a good tripod, using mirror lockup and timed or remote release. Set IS off for the 28-135, and try both with and without IS on the 100-400. Compare AF and manual focus. If your tests show consistent AF errors (all in the same direction) with one lens, then calibration may improve AF: if errors show with all lenses, then the body may need adjusting. Best calibration results are obtained by having Canon calibrate both lenses and the body. Focus testing needs to be done with care - it can be all too easy to make mistakes such as failing to realise that the focus point is actually sensitive to a wider area than the viewfinder appears to show.

 

Canon's own advice starts on p 33 of this document:

 

http://www.photoworkshop.com/canon/EOS_Digital.pdf