June 26 2013
Configuring the Pentax K5 to keep the same aperture when taking a series of bracketed photos in manual mode is important for High Dynamic Range (HDR) photography.
If the Aperture changes then the depth of field also changes, and this is not suitable for occasions when the bracketed shots are combined, such as HDR photography. The default setting on the K5 is for the Automatic Exposure Bracketing (AEB) function to change the aperture as well as the shutter speed for some of the photo series shot using AEB in Manual mode.
While it may say a contradiction to use an automatic function in manual mode, it still gives photographers full control over the main exposure, and they do set the number and exposure difference with the extra bracket shots. The main advantage is speed, and on the K5 it helps reduce the chance of camera movement as the only operation is to press and hold the shutter button down while the bracket series is being taken.
The configuration is not obvious from the menus or the manual. This is a series of menu shots showing each step in setting the manual bracketing to Aperture priority.
This is the first menu and move down to the E-Dial Programming option and select it.
This opens E-Dial Programming menu and unusually for the Pentax K5 this menu has two pages indicated by the number s on the top line. Select page 2.
The first option on page 2 of the E-Dial programming menu is for Manual bracketing. The right hand column shows mine has already been changed to TvShift. This means the AEB function alters the shutter speed.
Select this option and this is what you get, and it is not very clear what to do next
Move down and highlight the the second line and then select it.
Then this dialog box appears with the options. move down to the TvShift and select this option with the Ok button on the four way controller to confirm the selection. Then press the menu button to get out of the menu system.