DIY Photography Hacks: make an AF micro adjustment for precise focus
Test and calibrate your AF
Zoom in to maximum focal length and set your camera according to the checklist (left). Take a shot of the centre of the target, where the black-and-white squares meet.
Play back the image, then zoom in for maximum detail and check it to see where the point of focus falls on the scale. Better still, check the shot on your computer screen.
Our image shows a front-focus problem as the scale is sharper below zero; ideally you want the focus to be sharp at an equal distance both above and below the zero marker.
To adjust, press the Menu button and go to Custom Functions, then Autofocus/Drive. Each camera (and each manufacturer) has different Custom Function numbers, but they’re quite easy to find.
You can adjust all lenses by the same amount, or adjust each lens individually, or a combination of both. We chose the second option, to adjust autofocus for the individual lens.
As we had front-focus, we need to dial in a positive amount of AF micro adjustment. The exact amount depends on focal length and other factors, so trial and error is necessary.
Take another picture and check the image again. This time, the zero on our scale is crisp, with an equal amount of the scale in front and behind this marker in sharp focus.
Check your other lenses; if most are wrong pick Adjust All By Same Amount, then fine-tune individual lenses. Values are additive, so this example gives 4 steps of correction.
PAGE 1: Set up your AF micro adjustment & a DIY solution
PAGE 2: How to test and calibrate your AF
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on Thursday, January 24th, 2013 at 1:00 am under Photography Tips.
Tags: DIY photography, DSLR tips, How to focus