Samsung NX500 User Manual page 24

Concepts in Photography
DOF depends on focal length
The longer the focal length, the shallower the DOF. A telescopic lens with
a longer focal length will capture a photo with a shallow DOF better than a
lens with a shorter focal length.
A photo captured with an 16 mm wide-angle lens
A photo captured with a 100 mm telescope lens
DOF depends on the distance between the subject and the
camera
The shorter the distance between the subject and the camera, the
shallower the DOF is. Therefore, taking a photo close to a subject generally
results in a photo with a shallow DOF.
A photo captured with a 100 mm telescope lens
A photo captured close to the subject
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