22nd June 2007, 12:43 PM
How do I request calibrate a 2nd hand lens?
My cam is out of warranty, and am buying a 2nd lens (Canon) with a few days warranty left.
Is it possible to ask Canon to calibrate the lens for free?
The seller says the lens is calibrated to suit his cam, will it be somewhat 'off' when attached
to my camera?
22nd June 2007, 01:41 PM
Re: How do I request calibrate a 2nd hand lens?
Depends. Camera and lenses have focus tolerances that are +/- X, where X is an arbitary number. If it's calibrated for his camera, then his camera might have a back focus of 2 and the camera might have a calibrated front focus of 2, so the two combine to give a 0 tolerance, perfect focus. If your camera has a front focus of 1, then his lens will combine to give you a back focus of 1, because 1 - 2 = -1, that's still pretty close to 0 tolerance to produce pretty much no noticeable focus problems. However if your camera has a back focus of 2 or 3, then the two might combine to produce some noticeable problems.
Whether you need to calibrate or not really depends on your camera and its focusing calibration. For all you know, his calibrated lens still produces better results than most batches of that lens, new and factory calibrated. If it's noticeable, then you should be able to get free calibration under warranty. If it isn't, then you'll probably have to pay for it.