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Old Aug 1, 2007, 10:52 PM   #1
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Hi All,

Just received the lens yesterday, and have been playing with it a bit. Got it with a BIN price of $339 USD + $17 shipping, brand new, in the box from Cameraspot.com. They were very good to deal with, and offered the best price that I was able to find.

About the lens itself. It's not an EX, so doesn't have the fit and finish I prefer, but it seems to be built well, and I'm sure that I'll get used to the matte black finish, though I don't really like it. I tend to spend more time looking through a lens than looking at it, so this shouldn't bother me for very long. The zoom ring's rotation is smooth and doesn't creep (but it's still brand new, so that'll prolly change). The focus ring is actually pretty good, damped by friction, with a very slight gritty feel, but generally ok -- there's no quick shift like on the Pentax DAs -- so you have to switch the lever on the camera to MF. It's internal focusing, so the front element doesn't rotate, but the focus ring does while auto focusing. Being a DC lens, there's no aperture ring, and it's optimized for the APS-C format.

It's a tiny bit longer than the kit lens at 17mm, but unlike the kit, it grows to about 4.75" at 70mm. It takes a 72mm filter and weighs a pound.

It focuses pretty close -- to @ 8" (from the sensor plane, so the end of the lens is actually pretty close to the subject at 70mm), and the "macro" magnification ratios range from 1:4.7 @ 17mm to 1:2.3 @ 70mm. The max aperture shifts from f2.8 at 23mm to f3.5, then at 37mm to f4, and at just under 70mm to f4.5 -- using the info in the VF to determine the shift points. The lens focuses pretty quickly with the K10, even in marginal light. With the DS, AF is considerably slower, but that's expected. The Sigma 17-70 is not parafocal, so if you move the zoom setting, you have to refocus -- not by much, but it does need to be done.

The lens is sharp, but not razor sharp, IMO. IIRC, my impression of the DA 16-45 that I got to play with for a while was that it was noticeably sharper, but not enough to overcome the narrower FL range. I think it's a definite improvement on the kit lens (at least my copy), especially wide open, and has a half stop advantage at the wide end and a full stop advantage at 55mm, so it's faster throughout the kit's FL range, then adds another 15mm worth of reach at the long end. I think that the better IQ, extra reach and the wider max apertures are worth the cost of the upgrade price, but YMMV. The FL range gives you from moderately wide to a longish portrait. I was looking for an alternative to my Tamron 28-75/2.8, as I found myself wanting something wider a number of times when I used it. I haven't compared this lens to the Tamron yet -- if it stays hot, maybe I'll get a chance soon. . .

Here are some flower shots, the first at 17mm, 3 different apertures, then the last at 70mm, wide open (f4.5) and stopped down to f11

K10, Sigma 17-70 @ 17mm, f2.8 focused on the central flower



Then at f4


and at f6.3


The way I see it, the center IQ is hardly changed by stopping down, but the degree of OOF of the background changes significantly. I should be happy using it wide open, or close to it. . . The bokeh is a bit harsh, IMO though. . .

These were taken at 70mm, first wide open at f4.5, then stopped down to F11






Again, the central frame IQ is very close between these two apertures, so I'm pretty happy with the way this lens will perform for my projected use.

I'm impressed but not blown away -- from other users' reports I was expecting it to be a bit sharper -- but definitely a good lens for the speed, FL range, and price if you have a use for something with this combination. . . as most, I would think, have -- as a walkaround lens . . .

Scott





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Old Aug 4, 2007, 12:29 AM   #2
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Scott I really like the higher f/stop photos. They are pretty darn sharp.

Dawg
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Old Aug 7, 2007, 4:08 PM   #3
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Nice photos. How does the AF speed compare to the 18-55 on the k10d?
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Old Aug 7, 2007, 8:08 PM   #4
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Hi jaybilson,

The Sigma's faster -- just a quick and dirty comparison in normal room light, going from infinity focus to about 8 ft at 17/18mm. The 17-70 consistently got close, hesitated momentarily, then locked in one try, and the 18-55 just as consistently got close, made two corrections, then locked. I expected this, since the Sigma's at least a half stop faster at any given common focal length -- it's also sharper -- both of these factor into the focusing system's ability to get a lock.

Scott
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Old Aug 8, 2007, 3:10 AM   #5
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Thanks for the info. I am going on vacation at the end of this month and have to decide on a general use lens. I can get the new 16-50 or the 17-70+battery grip+extra battery+1.4x TC+wireless remote+small ball head+nice bag for an equal amount of money. What do you think I'll do? ; )

Jon
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Old Aug 8, 2007, 9:12 AM   #6
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jabilson007 wrote:
Quote:
I can get the new 16-50 or the 17-70+battery grip+extra battery+1.4x TC+wireless remote+small ball head+nice bag for an equal amount of money. What do you think I'll do? ; )
Get the 16-50. The rest of the stuff will follow as you explain to the one holding the wallet that you really made a mistake and need the TC etc.:-)

Seriously, when you've tried high end glass you have no desire to go back.

Kjell
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Old Aug 8, 2007, 6:49 PM   #7
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bilybianca wrote:
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Seriously, when you've tried high end glass you have no desire to go back.
I'd usually agree, but in this case, I made the decision for the Sigma based on my frequency of usage to cost factor -- and I just don't shoot really wide that often -- so it was either the Sigma or the DA 16-45/4, and the Sigma won for versatility, even tho it's not quite the lens that the 16-45 is, IMO. The DA*16-50 is just too pricey for the amount that I'd be using it. . . or at least that's what I'm saying right now. . .:-).

Now the DA*50-135/2.8 is another story -- my dealer called today and left a message saying that he just got one into inventory, and hopefully I'll be able to play with it tomorrow. . ..

So far, the Sigma has a place in my kit.

Scott
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Old Aug 9, 2007, 1:18 PM   #8
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I guess I could ask for the other things for Christmas, but I am going on vacation at end of the month and think they will be more useful. Hmmm...what to do? Maybe the cost of the 16-50 will go down or rebate by Christmas, but then hopefully there will be a 70-200mm f/2.8 available!

Jon
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