Walk Around Lens for Architectural and Model Shots I recently got this camera. I was using a sigma zoom lens at first. It had great image quality, but there were problems aligning verticals and horizontals. I traded that for a low end canon lens but the picture quality is awful. I shoot a lot of architecture and architectural models, plus whatever I see out in the world. I am looking for one lens that does those things really well and has good image quality. I am a starving student, so price is a BIG deal. Any suggestions?