Nikon Nikon Df Product Manual - Page 183

Non-CPU Lenses Non-CPU lenses can be used in exposure modes A and M, with aperture set using the lens aperture ring. By specifying lens data (lens focal length and maximum aperture), the user can gain access to the following CPU lens functions. If the focal length of the lens is known: • Power zoom can be used with optional flash units (0 119) • Lens focal length is listed (with an asterisk) in the playback photo info display If the maximum aperture of the lens is known: • The aperture value is displayed in the control panel and viewfinder • Flash level is adjusted for changes in aperture if the flash unit supports AA (auto aperture) mode • Aperture is listed (with an asterisk) in the playback photo info display Specifying both the focal length and maximum aperture of the lens: • Enables color matrix metering (note that it may be necessary to use center-weighted or spot metering to achieve accurate results with some lenses, including Reflex-NIKKOR lenses) • Improves the precision of center-weighted and spot metering and i-TTL balanced fill-flash for digital SLR t 163