I have unlocked lvl 1 and 2 and the second is kinda hard for me ;D

HInt:
you can squeeze a photo past Dutchess
You cannot squeeze a photo past terrance,

The Larger camera takes longer to shoot,
thus If you use the larger one you may only be able to get 1 or two shots when the characters pop up,
WHen you use the small you should be able to get 2 and sometimes three shots while the characters are poped up.

If you miss the character you needed they will usually reapear in about 30 -40 seconds. (on the later levels) So do not panic if you have to pass up a shot because of Terrence, but Do not pass up a shot if the time is low just to get extra points.

monty