i purchased several of your cheat cards for the lens I have. the basic starting lens 18-55, and i also have a 70-200 lens. the cards are great except i am not sure how to do some of the settings. is there a quick reference on how to change the particular settings on the cards? for example, i have trouble figuring out how to adjust the aperture. also when it says, for example, to adjust the zoom to 18m does that mean just start the lens at the 18 printed on the lens outside or something else?