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Lens fine tuning (1 Viewer)

Sbiriguda

Well-known member
I have a Nikon D3100 body + Sigma 150-600 mm lens that soon will be delivered. I got different suggestions...
Some say the tuning must be done by the official Sigma retailer (here it is 80 euros...). Some others complain they say if the lens is faulty it will remain faulty, the only solution is to ask a refund or a change and bringing to the retailer for tuning won't solve the problem.
Others say tuning can be done just by watching youtube video tutorials and using the "Dslrkit" calibration tool
And some instead told me that Nikon D3100 is too obsoleted and it doesn't even AF tuning (which is correct), so it doesn't even make sense to try to make the tuning on it...

I am puzzled... I think I will just don't do any tuning...
 

nikonmike

Well-known member
Fairly sure the D3100 does not have fine tune ability, have you checked the lens yet it may not need doing.
 

marcsantacurz

Well-known member
You can checkout this website / videos on using the Sigma dock fine tune. For the cost of the dock, you might just have the shop do it. https://www.diyphotography.net/calibrate-focus-lenses. I've not looked at the other video linked above, it's probably very good too.

As suggested above, first try the lens on a tripod and it might just work fine. What I do is fine a good high contrast target (or use the printable target from the link above) and on a tripod autofocus on it and take a photo, then look at it magnified. If it looks sharp, you're done. If no, you need to fine-tune. You want to do the test at the approximate distances you use the lens. For example, I sometimes setup the tripod where I can focus on a distant road sign (large black letters on white) so the lens is focusing at a longer distance.

What does fine-tune mean? On a DSLR, focusing is done via a secondary mirror to the AF system. it is not done via the main sensor. This means there can be a little variance between the distances to the AF system and to the actual sensor. AF fine tune adjusts for those distances. This results in what people call 'back focus' or 'front focus' meaning the actual image is focused either behind or in front of where you thought you were focusing.

higher-end cameras have a built-in system to adjust the focus. The d3000s do not, so at most you'll get some calibration from the usb dock.

Marc
 

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