Depth of Field
Depth of field refers to the zone of acceptable focus extending in front of and behind the plane of sharpest focus. As this zone is excep- tionally shallow at high reproduction ratios, previewing is desirable before shooting. To pre- view, press the depth-of-field button on the camera and the lens will close to the preselect- ed aperture to allow you to see how much background and foreground is in focus. Depth of field can also be observed by reading the color-coded indicators inscribed on the lens barrel. A pair of orange lines on either side of the white distance scale index line corre- sponds to f/32 which is the same color on the aperture scale. At close distance, so little is in focus that the depth-of-field tables on pages 13 ~ 14 are more useful.
NOTES ON FOCUSING
To avoid camera shake, close-up photog- raphy poses several problems not encoun- tered in general photography. One of these is sensitivity to vibration: the magnifica- tion of the image on the film makes even slight image displacement prominent and results in a blurred image. Therefore, for best results, mount the camera on a tripod or on rigid supports, and use a cable release to trip the shutter.
At extremely close working distances, depth of field decreases to the actual focused distance. This can be partially compensated for by stopping down the lens. But at very close distances an extremely narrow depth of field is inevitable. Careful placement of the subject, if it has depth, will be neces- sary to ensure that the important surfaces will be in the same zone of sharpness.
