I'm having a terrible headache - can someone please help

[Henry Goh]

Camera: 1Ds MK III
When I'm shooting at minimum distance, I need to micro-adjust my camera to -14 for my 85mm f/1.2 II. However, when I shoot at around 7ft to 8ft, this adjustment needs to be set at +7 for a sharp focus. How am I going to use this lens on this body without constantly doing focus adjustments? Have anyone observed similar behaviour? I'm almost giving up and keeping the focus adjust ment at -14 permanently for the 85mm f/1.2 II lens and using it it only for close portraits. Then calibrate my other 85mm lens the 85mm f/1.8 to suit 7ft to 8ft shooting. What a big bother this will be.

Please tell me how I can get this fixed properly Thanks.

BTW when the first lens is set at -14, the image at the focus point is tack sharp with a beautiful fast drop off in focus, the reason why we buy this lens in the first place, no?

 

[Ben Rubinstein]

Sounds like the lens needs to go in, probably a misaligned element.

 

[matthewpereira]

I agree - sounds like it needs a visit to Canon. Did you buy it new, or second-hand?

 

[Henry Goh]

All my lenses were bought new.

I have just did the same kind of tests on a few other lenses like a Sigma 50mm f/1.4 and a 24mm - 70mm f/2.8. I observe the same kind of behaviour. I don't think the camera nor the lenses are faulty. I believe if you find the time to check your kit, you will notice similar behaviour. I think when a lens is calibrated to the short side it won't focus correctly to the far side. I now remember Canon recommending calibrating lenses at a distance of 50x the focal length. Hence an 85mm lens should be adjusted for focus at 4.25m. For now I'm going to take measurements and label my lenses so that if I shoot near minimum I will reset the focus adjustment for optimal sharpness.