[shuttertalk]

The *ist DS is the flavour of the month with me -- what are people's opinions regarding the Sigma 18-125 DC and use of it with this camera ? Or even just the lens in general?

Stores in Oz tend to sell either *ist DS either with the kit lens (Pentax 18-55) or the Sigma 18-125.

Any opinions?

[slejhamer]

Avoid all sigma lenses except for their EX series. I would tell you to avoid all sigma products in general, but some people have luck with the EX series lenses.

If you want an inexpensive all-purpose hyper-zoom lens in a small body, consider spending US$100 more and get the Tamron 28-300 XR Di. It's not the sharpest or the fastest, but tough to beat for versatility in that price range. Plus it's got a 6-year warranty.

And here's an important point: "Digital camera" lenses like Sigma's DC series only work with cameras that have APS-size sensors. If you ever upgrade to a 1.3x or full-frame camera, you are stuck with a poor-performing Sigma paper weight. On the other hand, Tamron's "Di" series has improved optics that perform better with digital cameras (less flare, less chromatic distortion) but the lens will still work with full-frame digital and film SLRs.

Remember, DO NOT UPGRADE YOUR LENSES!

[shuttertalk]

Thanks mitch!

Lol... are they really that bad? Any user opinions or references you can point me to?

[Toad]

I can second the vote of confidence for the Tamron Di series. I have 90mm Di macro and it is outstanding.

[slejhamer]

Sorry Jules, I'm just anti-sigma after having my old sigma lens' internal coating flake off, then going through a lengthy and costly delay at sigma's service facility getting it cleaned, and then having the internal coating flake off AGAIN. plus the lens was not at all sharp wide open and really needed to be stopped down to f/8 to be usable. and it distorted at the edges, even on a 1.6x sensor. and that was a top-of-the-line EX lens!

The lens you are considering looks okay for the price and I've heard that it's surprisingly sharp. The sample pics at photosig look good.

[adam]

Get the 18-50

[shuttertalk]

Thanks guys ... now you got me drooling over the 28-75 f/2.8...

http://www.tamron.com/lenses/prod/2875mm_lg.asp

I think vs the Sigma 18-125, you would lose the wide angle and telephoto aspects (45-120 vs 28-190) as a trade off for the f/2.8 constant aperture. Still, 45-120 is a usuable standard range...

[EnglishBob]

Another Tamron Vote, I have 3 "Quantaray" lenses.... these are sold by Ritz Camera in the US and are rebadged Tamron lenses. I like mine.

[shuttertalk]

Another Tamron Vote, I have 3 "Quantaray" lenses.... these are sold by Ritz Camera in the US and are rebadged Tamron lenses. I like mine.

Which lenses specifically, Craig? Feedback on them?

[Rufus]

I've had a Sigma which lost it's coating too, plus one which was the most awful lens in the world, and one which packed up autofocussing.
NN will not touch them for use with the ISTD because, (the story goes), Sigma refuse to pay Pentax for comms specs. Consequently, Sigma and Pentax equipment's compatibility can be hit and miss.
Maybe.


Having said that, I have the 17-35 EX DG, and it's extremely good, (with 10D), but the 17-35 EX was the aforementioned "awful" lens.

YMMV

[shuttertalk]

Looks like the Sigma scorecard isn't looking too hopeful at the moment...

[slejhamer]

Consequently, Sigma and Pentax equipment's compatibility can be hit and miss.

This is a common complaint with Sigma lenses on Canon bodies, too. The lenses sometimes need to be sent to Sigma and rechipped.

Jules, the Tamron 28-75 XR Di is a sweet lens, and considered outstanding for the price. Many people use it as their primary walk-around lens.

One caution: quality control seems a bit sketchy, probably the result of Tamron having to speed up manufacturing to meet the unprecedented demand. Buy it locally, test it out, and if it's not sharp at all apertures and all focal lengths, take it back and replace it for a different one. It should be reasonably sharp at f/2.8 75mm. Please read THIS THREAD for related info.

Also the Tamron 17-35 f/2.8-4 XR Di is getting some good reviews, should you decide that you need a wider lens later on.