8-16mm HSM focal range is weird, calibrate?

xpatUSA wrote:

Thanks for the examples.

The f/7.1 shot is blurred from top to bottom, not just in the distance:

7.1 vs 4.5, near:

7.1 vs 4.5, far:

Yep… although there are plants (mostly) in focus in the mid-ground, which is super weird.

I calculate** the hyperfocal distance at f/4.5 to be 786mm and at f/7.1 to be 487mm - both of which are more the published minimum focusing distance. Therefore, shooting focused at those distances should theoretically get you from "infinity" to half those distances.

Same number I got using a calculator. I tried focusing around that mark (hard to be sure since the distance gauge is off) and most of the image was still blurry.

That was when I began to suspect the lens was a bad copy but I was hoping to hear otherwise!

It's so weird, some shots will be fine and others won't. The issues are inconsistent. It feels a little like having a concussion!

Here's a street shot at 8mm and f/8 on an SD15:

Focused on the end of the street and sharpened in RawTherapee. I have another taken around the same time with the lens set to the infinity mark. It is softer, which tells you nothing because modern infinity marks are no longer accurate unlike older lenses for film cameras ....

A much crisper result from what I'm seeing even on the better shots I've managed to get, I think!

If you got the lens cheap, you could stick to f/4.5 and focus manually ignoring the markings; otherwise send it back if possible.

It was $299 — cheap compared to the Japanese resellers in the $400s, but not cheap enough to live with. Bummer!!

This is now 2/2 bad experiences with used Sigma SA lenses, meanwhile my adapted macro lenses work beautifully once I figured out how to use Cornerfix. I'm feeling a little salty about it.

This might be of interest:

http://www.trenholm.org/hmmerk/DOFR.html

Cool, thanks for your advice and the pointers! I really appreciate your opinion.

BTW… I think this may actually be your SD1M? I bought it off Scott!