Pentax K-7 Operating Manual page 79

Set the flash compensation value by turning
the rear e-dial (',,,_,,,')in the [Flash Mode]
screen. Pressing the ® (Green) button
returns the flash exposure compensation to
the default setting (0.0).
• The flash exposure compensation cannot be set in m (Green) mode.
• _.-+ appears in the viewfinder and on the LCD panel during the flash exposure
compensation. [p.31, p.33)
• If the maximum flash output is exceeded when corrected to the plus (+) side.
no compensation will be effective.
• Compensating to the minus (-) side may not affect the image if the subject is
too close, the aperture value is small or the sensitivity is high.
• The flash compensation is also effective for external flash units which support
P-TTL auto flash mode.
You can also shoot while the flash is being
charged.
Select [On] for [30. Release While Charging]
in the [C Custom Setting 5] menu (p.87).
Pictures cannot be taken while the flash is
charging by default.