Another is my Sony 1670z good? thread

Started Apr 20, 2017 | Discussions thread
devinw Regular Member • Posts: 147
Re: Another is my Sony 1670z good? thread

rjjr wrote:

devinw wrote:

The decenter doesn't look that that bad on this one.

How much de-centering is acceptable? For me any de-centering is reason enough for rejecting a lens.

I don't know if you're aware, but there are things called manufacturing tolerances. There is no such thing as a perfect lens. EVERY lens has some amount of de centering of every element relative to the optical axis. The question is, is it to a point where it degrades performance. That is up to the designer to quantify and devolop a process to stay within those limits.

As we have seen, the standard tolerances on the 1670 are probably too loose, since factory passing lenses have upset customers with their degree of soft sides. In this particular case, though, I see soft soft sides at f/4 16mm, which will be due some to field curvature, but the left side "smudgy" region is maybe 15% bigger than the right. I'd say that's decent for one of these. They can get much worse. I've seen copies where the whole 1/4 of the left or right frame is blurry.

 devinw's gear list:devinw's gear list
Sony a6300 Sony E 16-50mm F3.5-5.6 PZ OSS Sony Vario-Tessar T* E 16-70mm F4 ZA OSS +8 more
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