Camera Clinic - Travel Photography by Randall Warniers

• Carry a camera with you wherever you go
• Four factors for successful photography: Camera + Light + Decisive Moment + Point of View
• Four fundamental rules
• Know our equipement thoroughly
• Notice the light
• Be prepared to photograph quickly
• Natural light in the early morning and in the late afternoon when the sun is low in the sky, is best for people photography.
• People photography in the middle of a sunny day is bad.
• A bright sunny day is good for architecture.
• Hazy light, overcast day, cloud over the sun is best for people photography.

Depth of field

Hyperfocal distance (超焦距)
The hyperfocal distance is the nearest focus distance at which the DOF extends to infinity; focusing the camera at the hyperfocal distance results in the largest possible depth of field for a given f-number.  Let f be the lens focal length, N be the lens f-number, and c be the circle of confusion for a given image format. The hyperfocal distance H is given by

Formula for DOF:

This means:

• DOF increases as f-stop increases or aperture decreases
• DOF increases as subject distance (distance at which the camera is focused) increases
• DOF increases as focal length decreases. 

Source: http://en.wikipedia.org/wiki/Depth_of_field