Nikon D70 manual Exposure Mode, CPU Lenses, Depth-of-Field Preview

Taking Photographs—Exposure

Exposure Mode

When the mode dial is rotated to P, S, A, or M, the user can set shutter speed and aperture as described on the following pages.

CPU Lenses

When using a CPU lens equipped with an aperture ring, lock the aperture ring at the minimum aperture (highest f/-number). At other settings, the shutter release will be

disabled and a blinking will appear in the aperture displays in the top control panel and viewfinder. Type G lenses are not equipped with an aperture ring.

Non-CPU Lenses

Non-CPU lenses can only be used in mode M, when aperture can be adjusted manually using the lens aperture ring. In other modes, the shutter-release will be disabled and a

blinking will appear in the control panel and viewfinder aperture displays.

Depth-of-Field Preview

To preview the effects of aperture, press and hold the depth-of-field preview button. If a CPU lens is attached, the lens will be stopped down to the aperture value selected by the camera (P and S modes) or the value chosen by the user (A and M modes), allowing depth of field to be previewed in the viewfinder (depth-of-field preview is not available with non-CPU lenses).

5—ISO Auto ( 142)

When On is selected for Custom Setting 5 (ISO auto), the camera automatically varies sensitivity in the range 200–1600 (ISO equivalent) to help ensure optimum exposure and flash level. In P and A modes, the camera adjusts sensitivity when the shutter speed needed to obtain optimum exposure would be faster than 1/8000 s or slower than a specified value (shutter speed may drop below the specified value if optimal exposure can not be achieved at ISO 1600 equivalent). Otherwise the camera adjusts sensitiv- ity when the limits of the camera exposure metering system are exceeded (mode S) or when optimum exposure can not be achieved at the shutter-speed and aperture selected by the user (mode M).

When sensitivity is altered from the value selected by the user, ISO AUTO flashes in the control panel and viewfinder. In the camera photo information display for pictures taken at altered sensitivities, the ISO value will be displayed in red. Note that noise is more likely to ap- pear in photographs taken at higher sensitivities.

76