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Full Version: Lens Calibration - My Sigma 70-200 f2.8 HSM II
Dieselstation Car Forums > Multimedia > Photography > Gear & Equipment
Daz
After my last shot I possted a few people noticed it was slightly out of focus.

I then decided I should do a focus test on my Sigma 70-200mm f2.8 HSM II. So I setup my tripod with the camera at 45 degree's to the test sheet.

First up, This is how the lens was before fine tuning the AF for this lens.



Bigger Here

2nd Shot, this is with the fine tune AF set to +20



Bigger Here

Last shot, This is with the fine tune AF set to -20



Bigger Here


Am I right in thinking that this lens needs to go back to Sigma for calibration as nothing I do get's it quite right, +20 is a near as it gets.
Seethegrim
Damn, if you're having to do an adjustment of +20 thats a friggen crater!

The back/forward focus adjustment is meant to be tiny tweaks like -3 or +4.

You had best take it for a proper service if you want the best from that lens of yours.
Daz
I'm well confused with it now. I did another test with a lens box and a ruler at 45degrees and that showed I needed -14mm as that was the sharpest at 200mm f2.8

downside was I took some shots of my cat (aiming at the eyes) and the sharp ones were at 0 adjustment so I now have no idea if I have a problem or not.

Gonna dig up the warranty to see if it's still in date as per Martins comment in the other post.
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