Good point on choosing the ambient for adjusting focus. Some kinds florescent lighting can cause havoc to focus accuracy too.
D7000 with Nikon 16-35 F4 backfocus issues
- Thread starter Kirei
- Start date
Good point on choosing the ambient for adjusting focus. Some kinds florescent lighting can cause havoc to focus accuracy too.
Golagislow
Member
Thanks for the adv.
From my understanding, is it safe for me to do a testn calibrate if necessary at f/4 @ 40mm (since it is the sharpest from most of the reviews Also at test at f/8 @ 17mm & f/4 @ 70mm as well to see if any difference.
From my understanding, is it safe for me to do a testn calibrate if necessary at f/4 @ 40mm (since it is the sharpest from most of the reviews Also at test at f/8 @ 17mm & f/4 @ 70mm as well to see if any difference.
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Problem with testing at wide angles is, the DOF will not be so thin since the FOV is so wide, you will have trouble figuring out if the focus is spot on or not.
surrephoto
Senior Member
best way to check lenses of this class is to evaluate the bluriness of the background & foreground. it is not essential to have perfect 1/2 front & 1/2 back DOF & will depend on whether u prefer slight front focus or slight backfocus. eg. portrait slight front focus is pleasing for smoother background & the opp for landscapes as it is easy to achieve a reading closer to hyperfocal.
Golagislow
Member
Thanks for all the advices..
Hi Daredevil,
For canon, I heard it goes by serial number. For Nikon, the afma goes by the lens focal length n aperture. Meaning if u tune afma for a 85mm f1.4 n u mount another lens, the same afma is applied. Not sure if the body will differentiate between afd n afs lens though. But I did test on 2 x 85mm f1.4g before. For canon, they can have 2 afma for zoom lens. Nikon should have done that. Regarding the last part, how would we know that it's the lens characteristic n not manufacturer fault?
Thanks.
Hi Daredevil,
For canon, I heard it goes by serial number. For Nikon, the afma goes by the lens focal length n aperture. Meaning if u tune afma for a 85mm f1.4 n u mount another lens, the same afma is applied. Not sure if the body will differentiate between afd n afs lens though. But I did test on 2 x 85mm f1.4g before. For canon, they can have 2 afma for zoom lens. Nikon should have done that. Regarding the last part, how would we know that it's the lens characteristic n not manufacturer fault?
Thanks.
It goes by the type of lens. If you mount 2 lenses of the exact same model, afma will be applied. But if one is a zoom and another is a prime, they will be different. Question is, how many people out there will own 2 copies of the same exact lens and swap between them often. If you are one of those minority, you might want to consider sending one of your lens in. And for afma, you can always turn it on or off. Just program that menu item into your shortcuts.
Hi Daredevil,
For the second part, I was referring to your previous post that we should send the zoom in to NSC if let's say the afma is diff at 70mm n 200mm for the 70-200afs vr2 for eg.
Is there any way we can know if that is the characteristic? Or that copy of lens has issue?
And no I don't have 2 copies of same lens.
But I happen to goto NSC to demo n i went to a shop to test n I thought nikon would afma based on serial, but it didn't. Thanks
surrephoto
Senior Member
Hi Daredevil,
For the second part, I was referring to your previous post that we should send the zoom in to NSC if let's say the afma is diff at 70mm n 200mm for the 70-200afs vr2 for eg.
Is there any way we can know if that is the characteristic? Or that copy of lens has issue?
And no I don't have 2 copies of same lens.
Thanks
Based on my knowledge, they will be happy to fix this discrepancy between the wide-tele ends. Other than that, simple issues with AFMA should be done by yourself.
It is not fixable some times.
surrephoto
Senior Member
i think they will map out a curve of AF adjustment values for the focal lengths... so i think you're right, if too severe may not be fixable
