Lens AF-finetuning: Do YOU finetune your lenses and how?

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Lens AF-finetuning: Do YOU finetune your lenses and how?

Postby Stany Buyle » Sat 16 Apr 2011 09:19

AF finentuning of lenses is a wonderfull feature. It enabled my strong backfocusing tamron 28-75 F2.8 to become a tacksharp lens on my D700 as I described here.

Next to the option of buying the lens align system (http://www.whibalhost.com/lensalign/) which is probably the best but quite expensive tool for AF-finetuning there are several other ways to get your lenses AF properly, even perfect.


How do YOU do your lens AF finetuning?
kindest regards,

Stany
I like better one good shot in a day than 10 bad ones in a second...
http://www.nikonuser.info
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Re: Lens AF-finetuning: Do YOU finetune your lenses and how?

Postby Dodi » Wed 20 Apr 2011 11:21

Well, I know one can do AF tuning with test charts, and LCD screens, but I use a more pragmatic approach since years.

First of all, I take 3 identical boxes (I use cigarette boxes - bad habit) and position them on the table at different distances. Spacing depends on the focal length of the lens.
I focus a few times on the middle one and see which of the three is the sharpest. If the middle one is ok, fine, I put the boxes a bit closer to each other and give it another run.
If the middle one is still sharp, the exercise ends here. The test targets are more or less 30x the focal length in mm away, so approx 1000mm for a 35mm lens

If I had to do tuning, + or - to get the focus on the middle box, after the boxes I use a second step. I take an image of someones eyelashes at "normal" shooting distance for the lens.
This is a real life test. Usually I am ok, but sometimes this test reveals me I have to change +/- 1 AF step the original tuning.

I am too lazy to use a tripod, all tests are done handheld. In any case, you are going to handhold the camera most of the time anyway.
This system has worked for me since camera's came on the market with AF tuning possibilities.

Done it with all Canon L glass on EOS 5DmkII, 7D and 1DmkIV (all lenses needed tuning, except the 135L and newest 70-200 2.8IS II).

On my Nikons, it confirmed me that my D7000 needed a fixed correction factor of -3. That way it is ok with all my lenses, except the 35 1.4G and 85 1.4G. Those two lenses are the only
ones requiring tuning on my D3s and D700 too.
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Re: Lens AF-finetuning: Do YOU finetune your lenses and how?

Postby Lance B » Thu 21 Apr 2011 07:39

I have never needed to AF fine tune my Nikon D700 or D7000, but I did need to fine tune a few of my Pentax lenses when I was shooting with Pentax DSLR's. I generally used a focus test chart first off and then fine tuned the results in real world use by focusing on normal day to day subject matter and checking the accuracy. In fact, I found that focusing on real world subject matter was the most effective and accurate way of achieving focus in the long run.

Also, I checked the AF accuracy by using the lens wide open, and for zooms, also at the longest focal length.
Cameras:D700, D7000
Lenses:14-24 f2.8G, 16-35 f4 VR, 24-70 f2.8, 70-200 f2.8 VRII, 85 f1.4G, 105 f2.8 VR Micro, AF-S300 f4, 300 f2.8 VRII, 1.4x TCII, 2x TCIII.
Flash:SB600, SB700.
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Re: Lens AF-finetuning: Do YOU finetune your lenses and how?

Postby Leen Koper » Sun 24 Apr 2011 09:16

It may sound funny, but being a professional portrait phtotgrapher, I never felt the need to finetune my lenses. I always shoot at F4 or higher and any 'misfocussing' will disappear in the increased DOF at these apertures. In the studio I cannot go lower than F5,6 due to mu studio flash and outdoors -I mostly use my Nikon 70-300 zoomlens- I always stop it at least one stop down, mostly two, to get the maximum out of my lenses.

Moreover, I never noticed any significant deviation with the lenses I use and have used in the past. Maybe I 've been extremely lucky, maybe it has never bothered me as I never use full aperture.
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