I wonder if there is anybody here who can offer me a comparison of these two Canon lenses... I have the 24mm f/2.8 lens, and I have the 18-55mm f/3.5-5.6 non IS version (as well as a 50mm 1.8 and a 75-300mm zoom). By my logic, I should be able to merge these two lenses by selling them both and getting the 17-55mm f/2.8 EF-S IS lens. This would a. give me a wider focal length range of aperture-2.8-goodness, b. give me Image Stabilization which i do not currently have, c. reduce my footprint by shrinking my lens count from 4 down to 3, and d. give me an extra 1mm in wide angle view (ok this one's not really a valid point ) My only question is - is the 17-55mm lens as good as the 24mm lens when shooting at a focal length of 24mm? ie. zoomed in to a length of 24mm to match the prime lens. Is the lens comparable? Is the quality as good? Better? Worse? Or is the prime better? That's my only concern. I have yet to start saving for this, but I'm starting to think about it now anyway. Can anybody offer any opinions/detail about this? Thankyou!