It is possible to shift the program profile to favour a shutter speed one stop lower, with a correspondingly smaller aperture giving the same EV (sub-mode P L, giving in the example above 1/60 second at f/8), or a higher speed and wider aperture (sub-mode P H, in the example case giving 1/250 second at f/4). In this mode the camera selects both the shutter speed and aperture according to a programmed profile (that is, for any EV level, this mode offers a single combination of shutter speed and aperture for example, at EV 12, 'P' mode gives 1/125 second at f/5.6).
The dial locks in the 'X' mode there is a lock-release button in the centre of the dial which must be pressed to move it from 'X' to any other mode.
The mode dial has settings for programmed AE (P), aperture-priority (A v) and shutter-speed priority (T v) AE, metered manual exposure (M), auto flash (X) and a setting for long exposures (T). The exposure settings in use are also displayed at the bottom of the viewfinder. The viewfinder eyepiece has a shutter to keep out light when the camera is used away from the eye, and built-in diotric adjustment.Įxposure settings are controlled via menu options displayed in an LCD on top of the winder grip, and selected with wheel controls (one by the shutter release button, and another at the back of the grip, by the user's thumb) in combination with a main mode dial.
The meter measures between EV 2 (1/2 second at f/2.8) and EV 19 (1/1000 second at f/22) at ISO 100, and allows exposure compensation by up to three stops in either direction any selected compensation is shown in the VF display. The standard lens is an 80 mm f/2.8, as in the pictures.Īs in previous camera series, the prism finder has settings for spot (S) or center-weighted average (A) metering, and a setting (A-S) in which the camera automatically selects one or other of these, or an exposure between the two, based on the variation in brightness in the scene. However, the camera is not built in the modular way that those cameras were the power film winder is built-in, as is the AE prism viewfinder a waist-level finder cannot be used (although there is a right-angle eyepiece attachment). Many of the features of the 645 AF are retained from Mamiya's previous series of 4.5圆cm SLR cameras (the M645 Super and related models).
Perhaps Mamiya was sensitive to criticism of the previous, plastic body the introduction of the manual for the AF uses the phrase 'heavy professional use' a number of times. Whereas the M645 Super/Pro series cameras had polycarbonate bodies, the 645 AF series have aluminium bodies. The range of lens designations is very similar to that provided for the earlier, manual-focus cameras (the Mamiya M645 and M645 Super/Pro series cameras). The cameras have a new bayonet lens mount incorporating several electrical contacts, to support the use of AF lenses. These retain the ability to use either film or a digital back, switching from one to the other quickly, mid-roll if desired. It was followed in December 2001 by the 645 AFD, a version of the same camera made compatible with some digital backs (not produced by Mamiya at the time), and Mamiya produced improved models, the 645 AFDII and 645 AFDIII later. It was released in Japan in September 1999. The 645 AF is a medium format SLR camera made in Japan by Mamiya, the company's first auto-focus camera.