Close-up Photography

Exposure Compensation for Close-up Photography

When working very close to the subject, the exposure must be in- creased. The actual exposure factor will vary in accordance with the dis- tance that the lens is extended. (Optical law: Light intensity decreases by the square of the distance from the film plane).

Exposure compensation is easily determined by referring to the Expo- sure Compensation Scale.

After focusing the lens, read the exposure compensation factor on the scale. The scale is divided into three zones of light, medium, and dark shades. As indicated by the table at the base of the scale, the light zone represents an exposure factor of zero (no compensation is necessary), the medium shaded zone indicates +0.5 (a 1/2 stop increase in exposure is required), while the dark zone denotes a factor of +1 (a full stop increase in exposure is necessary).

To find the exposure factor, first locate the figure on the Focal Length Scale for the lens in use. Next, move along the scale, in the same column, until you reach the Distance Graduation. The shading of the zone (light, medium, dark) which touches the Distance Graduation indicates the correct exposure factor. For example, when the 110mm lens is focused as shown in the illustration, the correct exposure factor is +1.

The scale curve for each lens has a white O mark which coincides with the right-hand lens indication. So, use the mark to find the corresponding scale curve for each lens.

With a factor of +0.5, open the aperture by a half-stop. For example, assume that a hand-held exposure meter indicates a normal exposure reading of f /16 at 1/60 sec., for an exposure compensation of +1, set the lens to either f /16 at 1/30 sec. or f/11 at 1/60 sec.

When using a Mamiya through-the-lens (TTL) Exposure Meter Finder, such as the RZ AE Prism Finder, it corrects automatically for close-up photography.

• For optimum sharpness at the corners when using the 50 mm and 65mm wide-angle lenses at distances closer than 1 meter, use as small an aperture as possible.

• The bellows extension in millimeters appears on the top of the Focal Length Scale. These figures are used to determine the required exposure compensation factor when using extension tubes.

• For areas covered with the bellows fully extended, see the instructions for all interchangeable lenses.