hello guys and gals.. I have been looking at getting a 50mm 1.8 as my first prime lens. A friend has offered to give me a pretty sweet deal on a non d model...as in like $20..I can pick up the D model (same focal length) for a smidge over a 100 online. I wanted to see if anyone could tell me the difference between D and non D, I am planning on using this lens mostly outdoors...from what I can find online the D model gives information about the distance to the body and helps with flash exposure....is there anything else I should be aware of? As always I appreciate your help!