Doesnt work

I just purchased this app and if I was shooting with a Canon 5D with a 50mm lens at f16 it would be great. Unfortunately I am not. I am unable to select a camera model, focal length or aperture. I get the selection wheel that doesnt respond to any input. Wasted my money it seems, dont be wasting yours! Sorry but this gets NO stars.

Sir-bob about DOFMaster