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11-16-2009, 08:24 AM   #1
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New lens recomendations neede...

I've had the K100d for the last 2+ years with a 18-55 kit lens. I also own the Quantarray 70-300 zoom which I know is a pretty lame lens but for my non professional needs it does what I ask it too and has actually taken some decent photos.

My goal is to someday own the Sigma 10-20 or Tammy 10-24 for wide angle stuff which I really enjoy. But for now I am finding that I would like a better walk around lens to replace my 18-55. I would like something with bigger front end glass and something that will allow for a wider range of photos with good quality.

I am leaning toward the Sigma 17-70. It would dovetail nicely with my Quantarray giving me everything from 17-300. It would also fit nicely for down the road when I get the gream wide angle.

First question....I have read some reviews on the Sigma 17-70 but would welcome any other thoughts. Is it enough of an improvement over the kit 18-55 to legitimize the purchase? What are its strenths and weaknesses?

Second there another comparable lens to the 17-70...both in features, range and price I should be considering?

Thanks for any thoughts.

11-16-2009, 08:37 AM   #2
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I can't really give you a lot about the 17-70mm. I only tested it in a store one day and it's a decent lens but the variable aperture is a deal breaker for me. At the time I had a DA16-45mm Pentax lens and IMO it's a sharper lens that has a constant f4 aperture through the range. So I'd rather that even though it's a bit slower wide open than a lens that changes from f2.8 to f4 at some point.

The DA16-45mm is shorter but a stellar lens. There would be a gap to the 70-300mm but that's not a huge issue and you can make that up a lot by 'zooming with your feet' when needed.

The other thing you could give serious consideration to, is stick with your 18-55mm and add the Pentax 12-24mm lens. Of the wide angle choices we have available, this is the superior lens. I've owned the Sigma 12-24mm, 10-20mm and now this lens. It's sharper in the corners with less barrel distortion. The 10-20mm is far too soft in the corners and looses it's extra wideness because the edges are a blur at wider focal lengths. The Pentax has sharper corners and better colour rendition as well. So get that lens, use your kit lens and when the day comes, get the Tamron 28-75mm for your mid range stuff. Then you have the best shooting pair of zooms you would want IMO.

We've avoided the DA*16-50mm and it's a heck of a good lens. There is some barrel distortion wide open but it renders well and is very sharp. It just might be more than you want to spend.
11-16-2009, 12:33 PM   #3
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The 17-70 might be a bit sharper, but it's not going to be much faster (which is what I assume you mean n referring to the diameter of the glass). It's only f/2.8 at the very widest end. So it's not much of an improvement as far as that goes. The Tamron or Sigma 18-50/2.8 would be a better choice if that's you main concern. Or, if you're sure you're going to get a wide angle lens too, the Tamron 28-75/2.8 would seem a great choice as a basic walkaround.
11-16-2009, 12:49 PM   #4
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A common question.
The usual answers:
Tamron 17-50 - good image quality, not the best build, good value
Sigma 18-50 f/2.8 - similar to Tamron above
Pentax 16-45 - excellent image quality, slower (f/4 maximum), decent build quality and value
Pentax 17-70 - good image quality, also slower (f/4), quiet AF (SDM mechanism), good value
Pentax 16-50 - excellent image quality and build, quiet AF (SDM), expensive

If 24-28mm is wide enough for you:
Sigma 24-60 or 24-70 - reasonably good in all aspects
Tamron 28-75 - excellent value for money - one of the sharpest mid-range zooms available.

11-16-2009, 04:27 PM   #5
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Photozone really liked the Pentax DA 17-70 f4, for what it is worth. Klaus really thought it was pretty sharp in the 50-70 range, whereas the Sigma seemed to lose quite a bit at the long end. On the other hand, the Pentax has more distortion at the short end.
11-16-2009, 06:26 PM   #6
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QuoteOriginally posted by Ash Quote
A common question.
The usual answers:
Tamron 17-50 - good image quality, not the best build, good value
Photozone loved this lens on the Nikon mount, as did Thom Hogan.

It also has a terrific warranty.

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