Pentax K-5 Operating Manual page 72

How you hold the camera is important when taking pictures.
• Hold the camera firmly with both hands and keep your elbows close
to your body.
• Press the shutter release button gently when taking a picture.
Horizontal position Vertical position
• To reduce camera shake, support your body or the camera on a solid object
such as a table, tree. or wall.
• Although there are individual differences among photographers, the slowest
possible shutter speed for a handheld camera is generally 1/(focal length
x1.5). For example, it is 1/75 of a second for a focal length of 50 mm and 1/
150 of a second for 100 mm. Use a tripod or the Shake Reduction function
(p.139) when using a slower shutter speed.
• When using a telephoto lens, a tripod that is heavier than the total weight of
the camera and lens is recommended to avoid camera shake.
• Do not use the Shake Reduction function when using the camera on a tripod.
(p.139)