An underwater camera has a lens of focal length 35.0 mm and a maximum aperture of f/2.80 . The film it uses has an emulsion that is sensitive to light of frequency 6.00×10^14 Hz. If the photographer takes a picture of an object 2.80 m in front of the camera with the lens wide open.
a) What is the width of the smallest resolvable detail on the subject if the object is a fish underwater with the camera in the water?
b) What is the width of the smallest resolvable detail on the subject if the object a person on the beach, with the camera out of the water?