I have a Nikon D80. I am planning to buy the Nikon 50mm 1.8 AF lens. I have a few questions. There are a bunch of "f" numbers at the base of the lens, from 1.8 all the way up to 22. I currently have a Nikon 18-135mm lens and a Quantaray 100-300mm. The Quantaray 100-300mm also has the numbers at the base that I am talking about. Questions is if I use the 50mm 1.8, will my aperture on the camera actually can reach down to 1.8? Reason I'm asking is on the Quantaray i have to adjust the "f" number on the lens to f22 in order for the camera to detect it. Also another question, at what length on my 18-135mm do i zoom to get the equal focal length of the Nikon 50mm. Pretty much I want to see how it looks like so i can try out the distance in my 18-135mm first before I buy it. I know digital lens is a bit different in focal length then film lens. So I do not know if the Nikon 50mm is the same distance as if I zoom the 18-135mm to 50mm. I hope I made everyone understandable. Thanks for any inputs.