HP 945 Second release priority, Noise Reduction for Long Exposures, Shutter, Priority, Aperture

Icon	Setting	Description
Tv	SHUTTER	Lets you select the shutter speed in Live View
	PRIORITY	using the	buttons, while the camera
		selects the appropriate aperture setting. This
		allows you to create special effects using the
		shutter speed (such as blurring the moving
		water in a stream).
Av	APERTURE	Lets you select the aperture setting
	PRIORITY	(F-number) in Live View using the
		buttons, while the camera selects the
		appropriate shutter speed. This allows you to
		control the depth of field (for example to blur
		the background).

2-second release priority

When the exposure mode is set to ACTION, you can take multiple pictures in rapid succession without having to wait for the camera to measure focus and exposure for each picture. Release and then re-press the Shutter button all the way down within 2 seconds after taking a picture, and the camera takes the next picture using the same focus and exposure measurements as the previous picture.

Noise Reduction for Long Exposures

At longer shutter speeds the camera will automatically take a second exposure with the shutter closed in order to measure and reduce the noise (grainy look) in the image. In these cases, the exposure will seem to take twice as long as expected. For example, in a 1-second exposure, the active display will stay dark for 2 seconds until the noise reduction frame is exposed. This means that at longer shutter speeds, you may not be able to take quite as many shots back-to-back.

Chapter 2: Taking Pictures and Recording Video Clips 39