Lens Calibration

[DavidTO]

When you send your lens in to Canon (or others) for calibration, what do they do? How do you know you need it? Anyone had their lens calibrated and seen a marked improvement?

[wxwax]

Ian posted a link to a great site by a sports photographer. Here's what he says about measuring for focus.

These days, I periodically check the focus on my camera bodies. I take a long lens and set it up on tripod. Then I attach a body to the lens and focus on something and mark the focus ring with a fine pencil. Then I change bodies, refocus on the same object and see if the focus is exactly the same. I do this for all of my bodies. If the focus on one does not agree with the other bodies, then I know I have a problem with that body and I get it fixed.

Source (http://www.astropix.com/SPORTSPIX/FOOTBALL/FLIP.HTM)

Umm, one catch - you need a second body!

[DavidTO]

I was referring to sending it into the manufacturer for calibration. I saw it referred to on the FM B&S forum. Just want to understand what they do, and why one would send their lens in. Also curious how much it costs.

[wxwax]

I figure that's how he decided there was a problem. Either I've been amazingly lucky, or there actually aren't that many lenses/bodies out of calibration. I suspect the latter. :dunno

[ian408]

I was so excited to see this. I thought "finally, I can see what this
CA adjustment in PS is all about".

This was something Marc mentioned all lenses have. I was trying to figure
out how one went about making this adjustment.

Any ideas?

Ian

[jeff lapoint]

just got my 200 2.8 back from canon today. i was having a bit of a focus issue, so i ran it down to irvine last wed. they recalibrated the lens, did a projection test, and cleaned and lubed all the parts. it was under warranty, so no charge. fast and very helpful service!

lens works like a dream now (and it didnt exactly suck before)