[juu]

I currently have a K100D + 18-55 Mk1 kit lens + some old manual lenses I don't use much (50mm f2 and Rokinon 80-200mm zoom from my K1000). Most of my pics are near 18mm currently I think.

I want to upgrade to a better walk-about lens.

I do some hiking in inclement weather so I've been looking at buying a WR camera with WR lenses but the 16-50 DA* seems to be too expensive for what it does while the 18-55 WR - not enough of an upgrade from my current Mk1 lens. And it might make sense to wait for a WR camera below the K7, as the K7 is both slightly above my budget and bulkier than I'd like. K-x doesn't have WR.

So looking at non-WR lenses the Sigma 17-70mm f/2.8-4.5 DC Macro seems a good option, however I hear conflicting reports on zoom creep - some say it has it, some that it doesn't.

And I'm not sure what sort of zoom creep it is. On my Rokinon zoom it is terrible - the lens extends and changes the weight distribution of the camera a lot, so it becomes ungainly to carry (and I carry my camera in my hand a lot).

How bad is it on the Sigma? If it's just that it zooms out to 17mm when carried without changing the weight distribution much I should be able to live with it. Enabling/disabling zoom lock seems a hassle after every shot.

I live far from decent photo shops so it might be difficult to find a real specimen to look at.

Any other advice?

[AdrianN]

If you're wondering about zoom creep while carrying the 17-70, it doesn't have any thanks to a little lock that's built into the lens.

[juu]

If you're wondering about zoom creep while carrying the 17-70, it doesn't have any thanks to a little lock that's built into the lens.

Yes, I know, but:

Enabling/disabling zoom lock seems a hassle after every shot.

[little laker]

I only used one for a week or 2, however all I remember from that period is several sweet images. I don't recall any zoom creep or anything else to annoy me.

I wouldn't hesitate buying one, if I wasn't more of a manual focus Prime guy

[hinman]

I have been using mine for over one year and I never notice any zoom creep. Usually zoom creep happen with lens with long zoom range and those with lens front heavy in a 1-touch zoom with loose zoom ring design tend to have zoom creep. I don't notice any. And compared to your kit's lens, it has the extra feature with a zoom lock at 17mm. Though you find it troublesome to engage the zoom lock, I find it great, practical and easy to use in hiking so that my lens is the shortest zoom position that is easier to carry and less prone to hit surrounding objects.

It is the best walk-around zoom in my gear.

Thanks,
Hin

[forensicscientist]

I have the 17-70 and have experienced no creep. Images are an upgrade from the kit lens too.....

mark

[juu]

Thanks, you've convinced me that the creep isn't an issue. And everybody says that the pictures are an improvement, which probably is the case.

The thing that puzzles me now is that I'm looking at the tests for the two lenses (Sigma 17-70 and my current Pentax 18-55 mk1) and don't see any significant measurable differences; if anything in some tests the Pentax seems to have better measurements.

Is the difference in some non-measurable things, like bokeh?

Sigma AF 17-70mm f/2.8-4.5 DC (Pentax K) - Review / Test Report

Pentax SMC-DA 18-55mm f/3.5-5.6 AL - Review / Test Report

[little laker]

Is the difference in some non-measurable things, like bokeh?

Yes, the difference is in something called Image Quality.
Although the kit lens is a fine lens for what it is the Sigma will usually give you a more pleasant looking image.
Which is what I always want.

[flippedgazelle]

Thanks, you've convinced me that the creep isn't an issue. And everybody says that the pictures are an improvement, which probably is the case.

The thing that puzzles me now is that I'm looking at the tests for the two lenses (Sigma 17-70 and my current Pentax 18-55 mk1) and don't see any significant measurable differences; if anything in some tests the Pentax seems to have better measurements.

Is the difference in some non-measurable things, like bokeh?

Sigma AF 17-70mm f/2.8-4.5 DC (Pentax K) - Review / Test Report

Pentax SMC-DA 18-55mm f/3.5-5.6 AL - Review / Test Report

Even if the 2 lenses are similar in measurebation tests, I think it's worth noting that the Sigma is wider, longer and faster.

[juu]

OK, that's a fair point.

Thanks for all your input.

[d.bradley]

Even if the 2 lenses are similar in measurebation tests, I think it's worth noting that the Sigma is wider, longer and faster.

Don't forget the close focus!

[code4code5]

Thank you for posting this... Now I have a excuse to do a lens test between the Siggy, the 18-55 and the 18-55 II. Perhaps I'll also include the M50 1.4 for a kick. I was thinking about doing it just this morning.

[juu]

code4code5, can you please post a link in this thread when you are done? I would be very interested.

[code4code5]

Here's a link to the thread in the Lens Discussion forum.

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/79196-4-lenses...tml#post802020

edit: Since everything was set up, I decided to do another test with just that lens running through the f stops. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/79202-sigma-17...tml#post802050

[juu]

Wow, that was interesting. To my amateur eye the Sigma seems more blurry than the kit with the prime ruling supreme. Perhaps I just didn't figure out where you have the focus, as you say the Sigma has a narrower DOF; the letters on the pill box were the easiest to compare for me.

Can you do something similar at 18mm and/or f3.5 between the Sigma and the 2 kit lenses?