Nikon Ai lenses Overview
Intro 1977. Manual Focus. Compatible only on Digital D3, D2,D1,D700,D300,D200
Nikon AI Lenses, introduced in 1977, were designed for the Film cameras of their day and yet can still be used on the top end digital cameras.
Manually focusing, they were the first generation of Nikon lenses to Automatically Index to the camera's internal light meter. The previous (non - Ai) generation did index but only if the user remembered to twist the lens aperture ring to its fullest extent to allow the indexing to click in.
Many of these lenses are classics and manufactured to a very high build quality. They were superseded by AI-s in the early 80-s but the technical difference between the AI-s and the Ai is small and has no relevence to the Nikon Digital SLRs.
These lenses are all manual focus.
D3,D2, D700, D300, D200
Allow their meters to be fully utilised by this lenses.
They inteface with the lense in two ways
1)The AI-s lenses, having no CPU chip, convey metering information to the cameras by linking their "Rabbit ear" prongs to the camera's apeture follower tab or AI aperture ring connecter. This is a protruding post located just outside the lens mount flange.
2)They allow you to enter aperture and focal length data for older lenses that don't contain CPUs (computer chips) via the Non-CPU Lens Data option in the shooting menu.
If you dont enter the info, then using 1) you can get spot and ceter wieghted metering only.
If you do enter the the info using 2) then you also get matrix metering.
The D1 series allow Center Weighted and Spot metering.
The D90,D80,D70,D70S,D50,D100 mid range cameras allow no metering with these lenses.
The D60,D40,D40x low range allow no metering with these lenses.
Digital Vari Program, P (program), S (shutter priority), A (Aperture priority) M (Manual).
The higher range D3,D2, D700, D300, D200 cameras can use AS-s lenses in Aperture Priority and Manual mode but not in Program or Shutter priority mode. The remaining Nikon Digital SLRs are not compatible.
They have a "rabbit ear" meter coupling prong at the 12 o'clock position. Each of the two "rabbit ears" have a viewing hole punched out to enable the second row of aperture numbers to be read.
They have two rows of aperture numbers printed on the lense barrel.
On the larger row of aperture markings, the smallest aperture is orange
On the smaller row (ADR or Aperture Direct Readout Scale), the whole scale is white.