Originally posted by stormtech On a whim, I just ordered the Sigma 17-50 EX HSM to go along with my incoming 50-150 - I sure hope the IQ is the same as your images from the 50-150.
Good call on the 17-50mm. From what I've seen, it's a heck of a lens. I've thought about doing the same thing many times before, but since I've already got the 10-20mm and the Tamron 28-75mm, I'm already pretty well covered there.
Don't put the credit card away yet! Now that you've got the Sigma 17-50mm and the 50-150mm, you need to add the book-ends of the Sigma 8-16mm and 150-500mm, so you'll be completely covered from 8mm-500mm with some of the best zoom lenses available for Pentax today.
And of course, now that you'll be covered from 50-150mm at f/2.8, you need to sell your 60-250mm f4 and start the search for a Sigma 100-300mm f4.