I need your opinion on the following 2 lens that I found in my area: 1) Minolta 70-210mm F4 (beer can) lens AF Perfect lens and UV filter included. **Is this the famous "beer can" lens everyone talks about? What is the difference between this and a regular lens this size? Why are they so great? 2) Minolta 50mm F1.7 AF lens Standard size on full frame and film cameras or equal to 75mm on Minolta or Sony digital. Excellent shape, no oil on the blades and has a nifty built-in lens shade. Also including a Minolta brand, thin design UV filter to help protect the lens. **Does anyone have the 1.7 lens? My 50mm is a 2.8. Am I going to see a huge difference with this lens? Is it a lot quicker and sharper? Better bokeh? What should I expect to pay for both of these lens? Thanks in advance.