Help diagnose K-3 II / DA* focal issues

enricoman · 05-16-2018, 09:06 PM

I retook the image at ƒ/5.6 as c.perkins recommended. The result is much better and is leading me to think I have unrealistic expectations of clarity at ƒ/2.8 :-(

The below image has a few adjustments (crop, lens correction, levels, sharpness)

Here is the untouched jpeg

MarkJerling · 05-16-2018, 09:40 PM

That's looking much better!

enricoman · 05-17-2018, 03:14 AM

Originally posted by MarkJerling

That's looking much better!

Indeed, but I still think f/2.8 shouldn't produce the image seperation seen in the previous images. I'd be interested in seeing a similar test with the same equipment.

**caliscouser** · 05-19-2018, 09:39 PM

I have had 2 copies of the 16-50. Both were 'glowy' wide open at 2.8 and only have decent sharpness right in the center at that aperture.

Stopped down they are much better and it is a very nice lens with high quality output if you get a good copy and shoot mainly stopped down.

Unfortunately both copies I had were decentered and I gave up on it. I was disappointed with the wide-open performance otherwise I liked the lens a lot.

enricoman · 05-23-2018, 07:08 PM

Originally posted by caliscouser

Unfortunately both copies I had were decentered and I gave up on it.

What do you mean by decentered? My 16-50 was sent to Japan to be "re-aligned" I assume you're referring to the same thing? The effects were, one side of each image would be out of focus in every shot, with a blue ghosting around objects on one side.

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05-16-2018, 09:06 PM	#16
enricoman New Member Join Date: Dec 2017 Posts: 12 Original Poster	I retook the image at ƒ/5.6 as c.perkins recommended. The result is much better and is leading me to think I have unrealistic expectations of clarity at ƒ/2.8 :-( The below image has a few adjustments (crop, lens correction, levels, sharpness) Here is the untouched jpeg

05-16-2018, 09:40 PM	#17
MarkJerling Moderator Site Supporter Join Date: May 2012 Location: Wairarapa, New Zealand Photos: Gallery \| Albums Posts: 20,406	That's looking much better!

05-17-2018, 03:14 AM	#18
enricoman New Member Join Date: Dec 2017 Posts: 12 Original Poster	Originally posted by MarkJerling That's looking much better! Indeed, but I still think f/2.8 shouldn't produce the image seperation seen in the previous images. I'd be interested in seeing a similar test with the same equipment.

05-19-2018, 09:39 PM	#19
caliscouser Site Supporter Join Date: Sep 2014 Location: SF Bay Area, CA Photos: Albums Posts: 1,037	I have had 2 copies of the 16-50. Both were 'glowy' wide open at 2.8 and only have decent sharpness right in the center at that aperture. Stopped down they are much better and it is a very nice lens with high quality output if you get a good copy and shoot mainly stopped down. Unfortunately both copies I had were decentered and I gave up on it. I was disappointed with the wide-open performance otherwise I liked the lens a lot.

05-23-2018, 07:08 PM	#20
enricoman New Member Join Date: Dec 2017 Posts: 12 Original Poster	Originally posted by caliscouser Unfortunately both copies I had were decentered and I gave up on it. What do you mean by decentered? My 16-50 was sent to Japan to be "re-aligned" I assume you're referring to the same thing? The effects were, one side of each image would be out of focus in every shot, with a blue ghosting around objects on one side.