sigma 24-70ex
I have the Pentax 24-90 and consider it to be an excellent lens on digital. It's more expensive than most mid-range zooms, but the extra few millimetres at the bottom end are worth having.
George
IMHO, it's worth every penny

Matt
Having said that I have a Pentax 24-90 as my mid range lens. It trades a little sharpness for fantastic colour performance but is still much sharper than "budget" lenses. The main benefit is that it is light and compact enough to have it on your camera all the time. The Sigma 24-70 won't take many good shots when it is in the boot of your car or bottom of your camera bag. The pentax is constant f4 compared to Sigma 2.8 but I have heard that the Sigma loses sharpness wide open. Buy the Pentax soon, the £300 price is a big reduction to enable remaining stocks to be sold off,
I also have the digital only 16-45 which is very sharp. Also benefit of smae filter size means I can share my polarising filter and Cokin mount between the two lenses.
Kevin Stephens
I don't think it is fair to say people are "unreasonably" anti-Sigma. They have well-documented problems with all makes of cameras. When they work, they're fine, but often they don't. I have one that refuses to do AF on an SFX (I've tried it on three), but it will on my other bodies.
Many people have reported exposure problems because Sigma chips aren't always coded correctly.
And finally, when the front element housing of one of my Sigmas became loose, I found that it was attached by means of double-sided tape! Not a screw in sight. This was a lens I purchased new.
With the one exception of a Vivitar Series 1 70-210 (manufactured by Komine), which is one of the best independent lenses ever made, I now follow the John Riley rule of "Pentax only".
George
And finally, when the front element housing of one of my Sigmas became loose, I found that it was attached by means of double-sided tape! Not a screw in sight. This was a lens I purchased new.
I doubt that was an EX, what did you expect for your money?
With the one exception of a Vivitar Series 1 70-210 (manufactured by Komine), which is one of the best independent lenses ever made,
I have an originl K version (no electrical contacts) of this lens and I agree. I also have an original Tamron SP 35-70 f2.8 which is equally as good, and a hell of a lot more compact than tthe current Sigma EX 24-90
I was only putting my recommendation for the Pentax 24-90 in context as being from someone who wasn't anti Sigma.
Lets not get sidetracked
Wishing you good light
Kevin
You rightly surmise that my tape-fixed Sigma was not an EX, but I have to say that for the hundred quid or so that I paid for it ten years ago, I did think they might have run to a few screw fastenings. I don't think that's an unreasonable expectation!
But I wasn't saying don't buy Sigma. Just check first.
G
I have both Sigma EX 24-70 DG 2.8 and the SMC-FA 24-90...
MZ-S and *ist D do not work totally satistactorily with the Sigma, yet this lens works fine on my Z1-p.....
Whereas, the Pentax lens works superbly on all the cameras...
Lens of choice - the Pentax...beacuse it focusses better than the sigma.
grahamwalton
Member
Birmingham UK