Nikon 25420 manual Lens Aperture Ring, Exposure

P, S, A, and M Modes

P, S, A, and M modes offer control over a variety of advanced settings, including exposure ( 45), white balance, and image optimization. Each of these modes offers a different degree of control over shutter speed and aperture:

		Mode	Description
	Programmed auto		Camera sets shutter speed and aperture for optimal exposure. Recom-
P			mended for snapshots and in other situations in which there is little time to
	( 40)		adjust camera settings.
S	Shutter-priority		User chooses shutter speed; camera selects aperture for best results. Use to
	auto (	41)	freeze or blur motion.
A	Aperture-priority		User chooses aperture; camera selects shutter speed for best results. Use to
	auto (	42)	blur background or bring both foreground and background into focus.
M	Manual ( 43)		User controls both shutter speed and aperture. Set shutter speed to “bulb”
			or “--” for long time-exposures.

Lens Aperture Ring

When using a CPU lens equipped with an aperture ring, lock the aperture ring at the minimum aperture (highest f/-number). Type G lenses are not equipped with an aperture ring.

Non-CPU lenses can only be used in exposure mode M, when aperture can be adjusted manually using the lens aperture ring (in other modes, the shutter-release will be disabled). The camera exposure meter and a variety of other features can not be used ( 97).

10—ISO Auto ( 76)

Use this option to enable auto ISO sensitivity control in P, S, A, and M modes.

Exposure

The same exposure can be achieved with different combinations of shutter speed and aperture, allowing you to freeze or blur motion and control depth of field. The following figure shows how shutter speed and aperture affect exposure.

Shutter speed Aperture

Fast shutter speed Small aperture (large f-/number)

Slow shutter speed Large aperture (small f/-number)

Reference: P, S, A, and M Modes

39