Nikon F501

Infobox_camera | camera_name = Nikon F501 (N2020)


type = 35mm SLR
lens_mount = Nikon F-mount
focus = TTL Phase Detection Autofocus (1 zone)
exposure = Center-weighted
frame-rate = 2,5 frame/s
dimensions =

The Nikon F501 (sold in North America as the N2020) was the first successful autofocus SLR camera sold by the Nikon Corporation beginning in 1986. A nearly identical, albeit manual focus version, called the Nikon F301 (N2000 in North America) was also available.

The F501 is a 35 mm single-lens reflex camera with automatic film loading and advance, also a first for Nikon. The built-in motor drive provided single (one exposure and frame advance per shutter button press) or continuous (shutter will fire and film will advance so long as the shutter button is depressed) modes. Film advance speed was 2.5 frames per second (frame/s) on continuous mode. Rewind was accomplished manually by a familiar rewind knob which doubled as a release for the back. The F501 was powered by four AAA batteries housed in the bottom of the camera body, although it could utilize AA sized batteries with an optional attachment.

The F501 used a through-the-lens (TTL) "passive" phase-detection autofocus method for establishing focus. Unlike active systems, which set approximate focus based of distance to the subject, the "passive" system utilizes a CCD to "see" the focus subject and focus in a manner similar to a human operator. This method is more precise than the active method, but requires more light to function. The F501 had two focus modes available, single, in which focus was established and would not change so long as the operator held down lightly on the shutter button, and continuous, in which the lens would continuously re-focus on whatever was in the focus area.

The F501 could be set for auto exposure, "hi-speed" auto exposure, "dual" auto-exposure, aperture priority, or full manual exposure modes, which would allow the user to set both the aperture and shutter speeds. The shutter speed and auto-exposure modes were set the by use of a dial on the top of the camera, while the aperture ring on the lens was used for aperture control. The "hi-speed" auto-exposure would tend to favor higher shutter speeds and wider aperture settings than the "normal" auto exposure mode, while the "dual" mode would offer "normal" auto-exposure with lenses at focal lengths less than 70 mm and "hi-speed" auto-exposure if a lens was longer than 70 mm.

Like all Nikon SLRs, the F501 accepts Nikon's F-mount lenses, but will only autofocus with lenses designated "AF." Likewise, full auto exposure will only work with lenses produced after this feature was introduced. In both cases, the camera will function with lenses without these abilities, but will not autofocus or have full auto exposure capabilities. AF lenses designated "D" add no functionality to the F501, and "AF-S" and "VR" lenses will not perform their special functions if attached to an F501.

The F501 had user interchangeable focusing screens, unusual for an autofocus camera, even in later years. Three screens were available for the F501. Also unique among autofocus SLRs is that the F501 also accepted standard threaded cable releases with an optional, but inexpensive, unit that would also function as a second, finger-activated shutter release button.

In design terms, the F501 took a different look from previous Nikon cameras. The introduction of a polycarbonate-clad body rather than metal, which caused the camera to be black instead of silver, was the most immediate and obvious change. Also new to this model was the addition of an extended grip on the shutter button side of the camera body, a feature which has grown in subsequent autofocus SLR camera designs ever since. Less obvious is the addition of a red stripe on the right hand front side of the camera. Although this has been a design feature of every Nikon autofocus camera since, on the F501 the stripe is horizontal rather than vertical.