21mm mini shootout

GeneV · 07-14-2009, 06:38 PM

I've got a group photo to shoot, which in last year required a 21mm fov at f/4/ or f/5.6 on a Pentax digital. So, this year, I tried out four lenses in my bag that hit 21mm. They are:

Pentax 21mm DA 21ltd f/3.2
Pentax DA 18-55 f/3.5-5.6
Pentax DA 17-70 f/4
Sigma 17-35mm f/2.8

So, I shot a newspaper on the wall. Not perfect, because I'm sure it is never exactly perpendicular, but anyone care to guess the ranking in sharpness at F/4 and f/5.6?

schmik · 07-14-2009, 09:21 PM

Originally Posted by GeneV

anyone care to guess the ranking in sharpness at F/4 and f/5.6?

Nope. Why don't you tell us.

mike

GeneV · 07-14-2009, 09:42 PM

I can post the newsprint photos tomorrow, if anyone cares, but the winner at the larger apertures was IMO a tie between the DA21 and the DA 17-70. The surprise was that Sigma finished below the kit lens, especially at the corners. Actually, any of these lenses do very well in the middle.

I had expected the LTD prime to do much better than any of the zooms, but my copy of the DA 17-70 seems to really shine at this focal length, even wide open.

felix68 · 07-14-2009, 10:13 PM

Originally Posted by GeneV

I've got a group photo to shoot, which in last year required a 21mm fov at f/4/ or f/5.6 on a Pentax digital. So, this year, I tried out four lenses in my bag that hit 21mm. They are:

Pentax 21mm DA 21ltd f/3.5
Pentax DA 18-55 f/2.5-5.6
Pentax DA 17-70 f/4
Sigma 17-35mm f/2.8

So, I shot a newspaper on the wall. Not perfect, because I'm sure it is never exactly perpendicular, but anyone care to guess the ranking in sharpness at F/4 and f/5.6?

Not a huge deal but the DA21 is f3.2, not f3.5 as listed. The kit lens is f3.5-5.6.

GeneV · 07-15-2009, 11:12 AM

Originally Posted by felix68

Not a huge deal but the DA21 is f3.2, not f3.5 as listed. The kit lens is f3.5-5.6.

Pardon my typos.

K206 · 08-08-2009, 06:11 PM

GeneV,

It sounds like the 17-70 performs similarly to the DA 21 at 21mm. Could you provide any additional thoughts? Contrast, etc.? I would love to see the samples...

I have the Pentax 17-70 - but I much prefer my DA 40. I was thinking about getting a limited trio (15-40-70 or 21-40-70) - but only if they perform significantly better than the 17-70. Any insight would be greatly appreciated...

PS- I have read that the DA 70 is noticeably better than the 17-70 at 70mm

*Andi Lo* · 08-08-2009, 08:30 PM

I do care

I'm in the market for either the Sigma 17-35mm, 15-30mm, 10-20mm, or the Pentax DA 12-24... if only you included the other three as well, but I think someone else testing the 17-35 should give me a ballpark on how good it is.

Let me guess the sharpness ranking:
f/4 > DA 17-70, Sigma 17-35, DA 21, DA 18-55
f/5.6> DA 21, DA 17-70, Sigma 17-35, DA 18-55