I was wondering if someone could give me a complete tutorial on using the Raynox DCR 250 on my Canon T2i? I am a beginner who does not have a clue about using this lens. I purchased my camera with two lenses; one 18-55mm and one 55-250mm. I would like to know which lens will work best, what f-stop setting I should start with, and what mode should I be shooting in. I just want a point to start from. Can anyone help?