The D50 does not have any optimization.. the 55-200 quanteray is a basic beginner lens.. but sounds like it is just fine for your needs. If your flash is now yellow.. that's not good. I would return it to the store while under warranty. The camera body has nothing to did with the wide angle of the lens.. your 18-55 is wide angle at 18 and mid-range tele at 55.. if you want a real nice one lens for the D50.. look into the Nikon 18-200.. but expect to pay at least $700 for it. Read the manual and i suggest you buy the Thom Hogan guide to the D50... it will help you.