Frustration with Calibration

[lovell]

Ok, I needed my 50L calibrated, as it suffers from back focus and the dreaded focus shift when shooting close and fast.

If memory serves me, this is the first time I needed a lens calibrated.  The Canon tech I talked with told me it would be a good idea to bring my 5D body too, to determine if it was the cause and not the lens.  I doubted the body was the cause, as it works great with several other L primes I use, but  regardless of that fact, I included the body in the package I sent Canon Irvine.

Well, I got both lens and body back, and the 50L does work better, but still not like the 35L or 85L, but better, and I'm happy.  The paperwork from Canon stated that they had to tweek both the lens and the body to improve close and fast AF performance.

But, when I use the 50L with my other two 5D bodies, it will not provide as sharp images as with the body it was calibrated with.  So do I send it back to Canon with the other two bodies?  With all three bodies?  Do I send all my lenses too?

I feel a bit exasperated, to say the least.  Should I remember to use my 50L only with the body it was calibrated with?  As for my other L primes, they all work fine with all the bodies.  Part of me wonders if I should just replace the 50L with the F1.4, and maybe this might be the fastest and cheapest way to go....hmmm

[jani]

Sorry for the late response, it seems like I only get a couple of days each month to respond to posts here.

But, when I use the 50L with my other two 5D bodies, it will not provide as sharp images as with the body it was calibrated with.  So do I send it back to Canon with the other two bodies?  With all three bodies?  Do I send all my lenses too?

I feel a bit exasperated, to say the least.  Should I remember to use my 50L only with the body it was calibrated with?  As for my other L primes, they all work fine with all the bodies.  Part of me wonders if I should just replace the 50L with the F1.4, and maybe this might be the fastest and cheapest way to go....hmmm

What you're experiencing seems like a camera calibration issue.

There may be minute differences in the sensor position for each camera. This is why the Canon service center needs the camera bodies to fix the problem.

In recent cameras (1D MkIII, 1Ds MkIII), Canon has recognized the necessity of microcalibration in the field (that is, anywhere else but with a service representative), and you can store microcalibration information for a number of different lens models.

If I recall correctly, you can also set a standard calibration amount for all lenses.

However, if you have two samples of the same lens model, and these need different calibration parameters, you can't do that in-camera.