Good potential with a fatal flaw

This app would be worth 4 or maybe even 5 stars if it werent for the slider controls used to enter focus distance and aperture. Not only are they hard to move accurately but most of the time they just wont move at all. If I had my way, these things would be banned from any app that requires even minimal precision. If this had roller wheels to set the distance and aperture, I think Id really like it but as it is, its pretty useless. I only gave it 2 stars for potential. Goodbye $3.99.

zombe3 about f/8 DoF Calculator