Infinity calibration

[FiveDeeThree]

Hello.

I am in need of advice returning to photography realising that much of what I once knew has escaped my head.

Thought it was logical to eliminate sources of error by calibrating lenses...

So, calibrating infinity focus.

Contacted Sigma for advice about range to take test images. They advised there is no specific distance but advised using a subject over 200mm that has something in front and behind.

Briefly reassuring until hyperfocal near limit emerged from my distant memory.

How can focus be tested at a range under the hyperfocal near limit?

Am I being thick?

Regards

Steve

 

[FiveDeeThree]

Is this just a forum for gear acquisition fetishists now? Oh well.

No competitions?

POTN gone as well...

 

[Angst]

I assume that you are asking this for manual focus lenses? Doesn't seem to be any need to do this on modern autofocus systems. When ive calibrated cheap Chinese lenses that have been slightly off, using something as close to the horizon as i can see at the time works fine. Obviously, theres is a calculation for it and the specific distance required gets further a way depending on the focal length but unless you are calibrating a 200mm f2 lens i dont think it really matters all that much.