Pentax K10D Operating Manual page 158

156
Using a (Hyper-manual) Mode
This mode is convenient for taking pictures using the same shutter speed
and aperture setting combination or taking intentionally underexposed
(darker) or over-exposed (brighter) photographs.
1 Effect of Aperture and Shutter Speed (p.138)
1
Set the mode dial to a.
4
2
Press the Green button.
Automatically switches shutter speed
and aperture to the proper exposure.
Turn the front or rear e-dial to change
to the exposure to your liking and take
a picture.
Adjust the shutter speed with the front
e-dial and aperture with the rear e-dial.