Wednesday, November 16, 2016

Indeed...

Indeed, there's something not quite right about the way my first Sony SEL 55-210mm f/4.5-6.3 OSS lens focuses.  As you may recall, I complained earlier on this blog about fuzzy dogs and racecars.

It took awhile to locate the problem.  First I tried to keep the Wide area AF points lit up over the subject and watched carefully to ensure this was the case when I had continuous AF enabled.  No joy.  My photos were sometimes obviously out of focus.  Then I tried selecting the center AF point only and found the images were no better in focus than with Wide area AF enabled.

I then photographed a static subject and found the areas behind the intended focus point(s) to be sharp, whereas the areas where the AF points lit up were obviously out of focus.  Further, this happened only at focal lengths greater than approximately 135mm.  I could replicate this behaviour on three different vintage Sony APS-C mirrorless cameras.  It was then that I drew the conclusion that the lens was at fault.


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A suitable static, not moving, can't go anywhere test subject

I took the offending lens to a local camera shop and they told me what it would cost to have Sony repair open it up just have a look and, well, I was slapped upside the head with massive sticker shock.  Normally repair facilities will give a free estimate of repairs so that you can decide whether to proceed.  At least this is what I experienced when living in the US.  But no!  Not in France.  Well, not at this (Sony) camera shop, at least.  They want 100Euro just to pry the lens open.  I could do that with a sledgehammer for a lot less than that, right?

The camera shop had a new lens they were willing to let go of for 350+Euro.  Ouch!  I wasn't about to suffer Long Lasting Post Traumatic Stress over a second round of sticker-shock, so I walked out.

Taking a quick look around the 'net I could find nothing locally to test before buying.  That left the obvious option of having something shipped to me.  In this case my next Sony SEL 55-210mm f/4.5-6.3 OSS came from Japan.  It arrived today so I set about taking a look at it's AF behaviour.  Here is what I found.


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The lens that just arrived focuses the way the gods intended.  I call this "Correct AF" performance.  That is, the portion of the subject nearest the camera is accurately in focus.  The "Incorrect AF" performance is still exhibited by the first copy of the Sony lens I have.  It's lack of AF accuracy is, even now, repeatable.

And speaking of repeatable, what you see above was repeatable in Wide area AF, Center, and with the single center "small" AF point enabled.  The new lens is behaving the way I would expect in every AF mode the Sony A6000 has.  I didn't have to spend a ton of money for my next lens, either.  It was separated from an A5000 kit ensemble, if the seller is to be believed, so it was being sold at a steep discount.  In any event, onward.  I have a sharp and properly focusing lens.  Yea!

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