A shorter zoom to replace my 18-250mm

Why not get a fast ~30mm prime to complement your current kit? The Sigma 30mm f/1.4 is a fairly cheap lens (compared to the Pentax 31mm) and should provide you with loads of fun.

Well gents, it's a helluva quandary. I have no doubt, and completely agree, that any other zoom lens starting at 18mm will be perfectly suitable paired with my 10-20mm. What attracted me to the 24-70 was the useful focal lengths for a walkabout, and the image quality throughout the zoom range (according to reviews I have read. Looking at the reviews of the Pentax 17-70 and comparing it with my Pentax 18-250, I get the impression I wont be getting any greater improvement in IQ within this focal range.

now reading reviews is one thing ( and I dont mean anecdotal reviews as I tend to read the reviews on photozone.de), but i always feel it best to temper reviews with user experience. The Sigma 24-60 seems to have decent write ups.

May need to investigate the 24-60 a bit more before considering.

No problem, I don't go away for a few weeks.

THIS PPG picture was taken with it

Have been lookig at the Sigmas and Tamrons (17/18-50mm). The Tamron comes out the best regarding IQ and overall quality. however, theres a Sigma wirth about three filters going on ebay for £150 (and counting) at the mo.

If I went for this focal range then a definate Pentax 55-300 would be my long ranger.

The prime lenses are not really on my radar at the mo. My 55mm prime gives fantastic portrait shots for me and with my macro converter gives great close up images too.

I have a 24-90 which is my favourite lens - I've found very little to fault it apart from looseness in the barrel when fully extended (though it doesn't affect optical quality). They're like hen's teeth now apparently - the last SH one I saw was £400. However you may prefer the overlap a 17-70 will give you.

Stan