WTB: Sigma 20-40mm f2.8


Link Posted 18/12/2018 - 23:08
16-85mm was one of my faves on apsc
Top notch lens, 👍👍👍
I know what i like, If not always why.


Link Posted 20/12/2018 - 08:47
barkin wrote:
I recently picked up a used Tamron 17-50. I wouldn't say the build quality is at all bad, given the price. For what I paid for it, I could wear out half a dozen for the cost of a used DA 16-50
Screw drive AF doesn't bother me - it seems damned fast on my K3, and I know the SDM won't fail...

Most importantly though, the images that it produces are top notch - if it got pinched, I'd get another in a heartbeat.

And it zooms/focuses the right way

The Tamron is a great lens if you get a good copy and in terms of value for money it can't be beaten. I only changed to the Sigma version due to the better build quality and the luxury of an in-lens focus motor, optically it's no better.

MikeyBugs95 wrote:
Jonathan-Mac wrote:
The US forum did an analysis of the three fast standard zooms for Pentax APS-C - the DA* plus the Tamron and Sigma 17-50/2.8s and the Sigma won overall. The Tamron is just as good optically but with poorer build quality and screwdrive AF, while the DA* is not as good optically and has the dreaded SDM failure.

Yeah I know about the problems of the DA*. I have a well used one with a dead SDM and terrible optics. I'd be willing to give it a second try but I've, again, kinda decided to go with the 16-85 for the obvious reasons of the better optical quality and better AF motor.

The 16-85mm is also very good but doesn't fill a gap left by and f/2.8 zoom due to the slower aperture.
Pentax hybrid user - Digital K3 & K200D, film 645 and 35mm SLR and Pentax (&other) lenses adapted to Fuji X digital
Fan of DA limited and old manual lenses


Link Posted 20/12/2018 - 09:53
I wouldn't mind 16mm at f/3.5 as today's cameras can more than make up the difference with one extra stop on the ISO.

Kim C

Link Posted 20/12/2018 - 10:27
HarisF1 wrote:
I wouldn't mind 16mm at f/3.5 as today's cameras can more than make up the difference with one extra stop on the ISO.

Maybe and it is an often used argument. But the 16-85 is a full 2 stops slower at the long end. Most of the criticism of the 16-50 is "wide open" at the long end. I do feel it incorrect to purely rely on so called reviews quoting performance wide open rather than the same aperture. When the 16-50 was introduced, it had very good reviews but it was the days of the K10. Basically the lens outperformed that sensor. More recent cameras have shown a weakness wide open at the long end. But at F5.6 it is sharp. I haven't done a side by side comparison but probably as sharp as the 16-85.

In most cases, it still produces very good images, especially printed ones rather than pixel peeping, at 2.8. Yes you can rack up the ISO on the 16-85 but that doesn't change the depth of field or change the Bokeh etc.


Link Posted 20/12/2018 - 11:00
Like just about everything, it's finding a balance / swings and roundabouts, lose the f2.8 but gain 35mm on the long end.
Tbh, the IQ from the 16-85mm more than made up for the odd time I'd want f2.8 with that lens.
For me most of those earlier (cheap) (relatively) fast zooms just didn't cut it wide open, I tried most at one stage or another. From lack of sharpness to awful fringing most of them fell short.
I think now, this new family of d fa lenses are showing us just how good good glass can be.
I know what i like, If not always why.
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