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Calibrating lenses, is it worth doing? How?

caj26 9 7 United Kingdom
25 Aug 2013 11:05PM
I find some of my photos not tack sharp, I wondered if its me!!Blush Or could it be my lens?Grin
mikehit 12 8.0k 13 United Kingdom
25 Aug 2013 11:17PM
It is easy enough to find out.
My preferred subject is a stake or similar in a lawn. Put your camera on a tripod or other firm support that is not prone to vibration and turn on LiveView (or mirror lockup). Set the aperture to fairly wide open (f4 of f5.6). Focus manually (using LiveView if you have it) on the stake just above the grass and fire the shutter with a remote release or with the self timer (this will avoid vibration due to you pressing the shutter button). If the stake is in perfect focus you know it is all working OK.
Repeat the above using autofocus. This is why I like using a stake in grass - if the stake is not in perfect focus the blades of grass will show you how far out it is; do this 4 of 5 times because AF is not perfect and you see how consistent it is.
Then repeat it again using the camera handheld. This will show you how good your technique is (it is best in good light so you can get a fast shutter speed and remove camera shake from the equation).

I am presuming from your thread title that your camera has micro adjust? If so then be aware that micro adjust will only work at the focal length you used in the test - resetting at one extreme of the focal range may put the focus accuracy for rest of the focal range out of sync. I have read several posts where people have done their microadjust then found the factory settings were actually the best compromise.
Overread 13 4.1k 19 England
25 Aug 2013 11:19PM
Also remember that micro adjust is only adjusting the focusing of the lens and camera; it won't affect the best possible sharpness with the camera and the lens (you have to send the combo into the lens manufacturer for calibration if you want that - having found that you're getting soft shots even in test conditions and its not a focus error)
caj26 9 7 United Kingdom
25 Aug 2013 11:55PM
Thanks, I will give it a go!Grin-I don't know if I have micro adjust will need to check-
redsnappa 19 2.8k United Kingdom
26 Aug 2013 12:16AM

Quote:I find some of my photos not tack sharp
If it was a problem with the lens none of your pictures would be sharp.
LenShepherd 13 4.4k United Kingdom
27 Aug 2013 9:07PM
One of the problems with micro adjust is getting the wrong end of the wrong stick or (as probably in your case) the wrong end of the wrong stick Sad
There are very few subjetys moden AF cannot focus on, but as camera instruction books mention, there are some subjects they may not focus on accurate.
Whether you have some unsharp shots because you are not holding the camera sufficiently steady, you are not using a fast enough shutter speed for subject movement, or you naively expect AF to always be good including with subjects where the instruction book warns it may not be good, needs sample images.
If your camera body is faulty every lens on it mis focuses all the time in the same direction.
If your lens is faulty it mis focuses in the same direction on every camera body.
Neither of these conditions are what you describe so fine tune is not a possible solution.
caj26 9 7 United Kingdom
19 Dec 2013 5:58PM
Thanks I appreciate your adviceSmile
thewilliam 13 6.1k
19 Dec 2013 10:31PM
Focusing needs to be most accurate when using wide-aperture lenses. Leica recommends that users send their f0.95 Noctilux plus the body on which it will be used to a service centre so they can be matched.

With more workaday lenses, it's worth doing the checks that Len suggests, with the camera mounted on a tripod.

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