It may be difficult to get your subject in focus when:
-there is little contrast between the subject and background
(When your subject is wearing a color of clothing that is similar to the background)
-the light source behind the subject is too bright
-the subject is shiny
-the subject includes horizontal patterns, such as blinds
-the subject is not positioned in the center of the frame
Use the focus lock
When you take photos in low light
Turn on the flash. (p. 43)
When subjects are moving fast
Use the continuous or motion capture function. (p. 58)
Basic functions 27