“Can you use this lens on a Nikon D300 and how much to repair AF? I have the Nikon - AF-S DX NIKKOR 18-55mm f/3.5-5.6 Zoom Lens and put in on my D300 the other day. It acted weird when I went to use AF, and then suddenly, but, slowly started focusing, but, not all the tme. That was just for like 5 minutes. Got it out today to look at it closer and now the AF is not working at all. It also took very, very grainy gray pictures the day I did use it for those 5 minutes although it was at dusk. Can you tell me what the problem may be? And also how much it would cost to fix the AF?”