Photos of Sigma 17-70mm f/2.8-4 DC Macro OS and SMC Pentax-DA 18-55mm F3.5-5.6 AL

Sigma 17-70mm f/2.8-4 DC Macro OS	SMC Pentax-DA 18-55mm F3.5-5.6 AL
50mm f/4.0	55mm f/5.6
50mm f/8.0	55mm f/8.0
50mm f/22.0	55mm f/22.0
17mm f/2.8	18mm f/3.5
17mm f/8.0	18mm f/8.0
17mm f/22.0	18mm f/22.0

The above photos are taken using Pentax K-x. Looking through the photos, I realized that the Sigma lens is much sharper and brighter than that of the Pentax lens. The colours are more vibrant (brighter) whereas Pentax colours are more saturated (unsure if it is the correct technical term but I meant darker).

I'm just a novice photographer trying to take photos for the fun of it. The above are just my opinion of using the lens. Can't wait to take this baby out for a shoot =)

70mm f/8.0