[jesalonen]

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Hi all,

I've been concidering a zoom to replace the kit lens I just sold, and have read reviews here and Photozone.de, and lots of posts in this forum and I began to wonder: does 17-70 have some serious flaws? I hear lots of good things about 16-45, little less about 16-50 but not any comments that I can find on 17-70. It is as fast as 16-45, has more attractive focal lenght and according to the photozone.de MTF charts, resolution is quite the same. Ok, it is a bit heavier and perhaps a bit more expensive (not that much!), has SDM anf less Ca than 16-45 plus 25 extra mm. I don't know if I'm ever gonna buy one 'cause I'm quite happy with DA's, but just got curious...

[asdf]

Hi all,

I've been concidering a zoom to replace the kit lens I just sold, and have read reviews here and Photozone.de, and lots of posts in this forum and I began to wonder: does 17-70 have some serious flaws? I hear lots of good things about 16-45, little less about 16-50 but not any comments that I can find on 17-70. It is as fast as 16-45, has more attractive focal lenght and according to the photozone.de MTF charts, resolution is quite the same. Ok, it is a bit heavier and perhaps a bit more expensive (not that much!), has SDM anf less Ca than 16-45 plus 25 extra mm. I don't know if I'm ever gonna buy one 'cause I'm quite happy with DA's, but just got curious...

I'm guessing it's: 1. the price. 2. it's fairly new and so photozone's review is fairly recent--I was hesitant to buy it before the review 3. the people who fell for the "f/2.8" of the Sigma and Tamron dentist drills probably won't be replacing their lenses any time soon.

I don't buy the size argument (it's not much bigger than 16-45):

NED BUNNELL: June 2008

[jesalonen]

Ned, you're right, it is only 2x3 mm bigger. I was referring to it's weight, +120 gr which of course isn't much.

I myself don't buy the 2.8 argument - my experience with Canon tells me that f4 is enough (for me, at least) if the lens i sharp wide open, which it seems to be.

But have you been happy with that?

[asdf]

But have you been happy with that?

Yes, I found the DOF at around f/2.8 with the M 50mm I have to be too narrow for portraits and macro photography. I can get a nice DOF at f/4-f.5.6 and exaggerate the bokeh by going to 70mm--and arranging so that the background is farther. At f/2.8 and two meters away, focusing on someone's eyes, you only get 9cm of DOF from the eyes, maybe, to around the ears, keeping some of the hair out of focus. Also, some of these lenses perform markedly worse at f/2.8, while the 17-70 is fairly consistent throughout its range.

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Last edited by asdf; 01-26-2009 at 12:37 PM.

[kenyee]

I think the main thing is it doesn't offer anything significant over the Sigma 17-70 except SDM and it's more expensive.

[rfortson]

One other thing to keep in mind is that it's SDM-only, meaning it won't AF on an older Pentax body (K100D and earlier). Not sure if it's an issue for you or not, but something to be aware of at least.

[GaryM]

I think the main thing is it doesn't offer anything significant over the Sigma 17-70 except SDM and it's more expensive.

It's also faster at 70mm, where every little bit of speed is valuable - and expensive.

I think the main thing is it doesn't offer anything significant over the Sigma 17-70 except SDM and it's more expensive.

1) Quick shift focus;
2) Most likely better performance on higher resolution sensors (14 Mp and more);
3) O ring protection at mount;
4) Different colors - cooler rendering vs warmer for the Sigma (matter of personal taste);
5) Better border performance across most fl and f numbers;
6) 67mm filter size vs 72mm on Sigma (read cheaper filters);
7) Less vignette (light fallof) across most fl and f numbers;

Radu

[Arpe]

It's also faster at 70mm, where every little bit of speed is valuable - and expensive.

Only at the very very end of the 70mm end is the Sigma at 4.5 rather than 4, so yes it's slower but only at the very very end. Good bang for buck.

[heatherslightbox]

I'm thinking I'd like to get myself a DA17-70 one of these days, but in addition to not having the money right now, I'm waiting on the price to drop a bit more, although Prodigital2000 has a good price on it right now:
PENTAX smc DA 17-70mm f/4 AL (IF) SDM LENS FREE FILTER! - eBay (item 130283207676 end time Jan-29-09 17:24:38 PST)
Unless I run into a pile of money soon, that purchase will most likely have to wait until at least May after I get back from my trip to Tennessee.

Heather

I don't know about you guys (and gals ) in the States but in Europe the new stock comes with far bigger prices for all gear in general and some lenses in particular. This is the result of the new strengthen Yen against Euro and some other currencies so you may regret not buying at this prices very soon. Also Pentax seemed to up the prices on some lenses (again more high end ones).

Radu

[jamesm007]

Hi all,

I've been concidering a zoom to replace the kit lens I just sold, and have read reviews here and Photozone.de, and lots of posts in this forum and I began to wonder: does 17-70 have some serious flaws? I hear lots of good things about 16-45, little less about 16-50 but not any comments that I can find on 17-70. It is as fast as 16-45, has more attractive focal lenght and according to the photozone.de MTF charts, resolution is quite the same. Ok, it is a bit heavier and perhaps a bit more expensive (not that much!), has SDM anf less Ca than 16-45 plus 25 extra mm. I don't know if I'm ever gonna buy one 'cause I'm quite happy with DA's, but just got curious...

I don't have the sales figures but I bet its not very high for this lens; I bet Pentax is probably looking at poor numbers. Why? The Sigma 17-70mm and Tamron 17-50mm f2.8, and the lower cost of the Pentax 16-45mm. The new Pentax 17-70mm is not really optically better than any of those lens. It may have a tad higher resolution at 17mm versus the Sigma, but the Sigma is good at f2.8 just a tad soft in the deep corners, and the Sigma is better at the 70mm end, yes its f4.5 but stays f4 till 63mm, it also has lower CA/PF than the Pentax and can do a good pseudo macro. The Tamron is fast, but sacrifices a little at the long end (20mm). The Pentax has SDM, and some weather sealing.

Pentax should have differentiated it a little and not take on the Sigma 17-70mm macro. A simple change in specs like making it a 16-70mm or better 16-80mm would have made it a Sigma killer. Nikon has it. Just think a 24-120mm (16-80mm) f4 lens, with SDM and half weather-sealing, and good performance ratings from reviews. I have the Sigma 17-70mm f2.8/4.5 macro, I really like this lens for its great optics and versatility, its a superb walk around lens.

[Zebooka]

1) Quick shift focus;
2) Most likely better performance on higher resolution sensors (14 Mp and more);
Radu

1) There is a "hack". With your forth finger on right hand you can press lens dismount button. (I do quickshift with my sigma like this and also I have AF on AF button)
2) It's not necessary for a zoom. Sigma 17-70/2.8-4.5 performs quite well. It is enough for 10mp. If you wanna razor sharp images - buy limited or other primes

[Mallee Boy]

Hi Jesalonen,
My wife & I own a K20 & K200, basically the K200 is her camera and was fitted with the Sigma 18-125. I bought her the Pentax 17-70 f4 and she loves it.

Images aren't too bad either.

Cheers.

1) There is a "hack". With your forth finger on right hand you can press lens dismount button. (I do quickshift with my sigma like this and also I have AF on AF button)
2) It's not necessary for a zoom. Sigma 17-70/2.8-4.5 performs quite well. It is enough for 10mp. If you wanna razor sharp images - buy limited or other primes

1) I know this hack and whilst you feel good enough to do so I wouldn't and I also don't think it's equal to the "real thing" DA series has;
2) I only said that IMO DA17-70 is much more future proof because sensors will evolve in time to more Mps. Not many people have the resources to buy 3-4 primes in the 17-70 range as those could be many times (maybe 5x) the price of a zoom.

Radu