Nikon D7100 left focus issue

Started Apr 19, 2013 | Discussions thread
lock
Veteran MemberPosts: 5,780
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And about his mistakes...
In reply to PepsiCan, Apr 20, 2013

PepsiCan wrote:

lock wrote:

Than read about the incidence of the left sensor af problem in relation to the maximal aperture of the lens, and find the difference between the sigma and the nikon.

Lock

But sorry, no. The results Nikonman gets in his tests are questionable at best and can be attributed to other things besides camera focus failure. The mistakes he makes are:

- no use of single focus point but auto area

irrelevant if you would have studied his samples(see below). The auto area mode only used focus point that were all straight on the box. Left and right samples had confirmed focus lock, both measured at 1.68 mtrs.

- no comparison against a reference, I.e. PDAF vs CDAF

This could differentiate between a lens and body issue. However, he showed two lenses with the same symptoms. It is highly unlikely that these lenses suddenly become e.g. decentered in the same manner, causing the left af to off in both.

- not clear whether he shoots shutter or focus priority

Irrelevant because focus lock was confirmed in all samples.

And this has been pointed out to him many times in the threads he started.

Did you actually take the time to look at the samples he provided on flickr ?

left side 70-200

right side 70-200

AF does fluctuate to some degree. To exclude this random error I would have adviced him to explicitely test the left and right side more than once, but with the same scene. Say 10 times for each. But so far, I'd say he pretty much gave a good hint of the left AF issue (he also posted the 35 mm 1.8 samples).

lock

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