Nikon 13187 User Guide (en)

Non-CPU Lenses
By specifying lens data (lens focal length and maximum aperture), the user can gain 
access to a variety of CPU lens functions when using a non-CPU lens. 
If the focal length of the lens is known:
• Power zoom can be used with optional flash units (
• 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