659. Stop To Use

Stop To Use. Depth of focus is a very essential factor, and in order to reproduce all portions of the subject perfectly sharp, a mediumly small stop will have to be used. F.16 or U. S. 16 will, in the majority of cases, be the proper stop to employ when the subjects are all in one plane and the distance from the nearest point of the object to the farthest is not over 2 inches, with the lens of the camera 2 feet from the nearest portions. The farther the lens is from the object the greater will be its depth of focus, of course, but when employing a rectilinear lens the stopping of it to 16 will insure equal sharpness throughout.

660. Plates

Plates. An ordinary slow or medium speed plate may be employed when photographing the average subjects. Flowers, however, and all material in which it is important to bring out all of the color values, should be photographed on color sensitive plates - preferably panchromatic or trichromatic plates. A lemon-yellow ray filter, increasing the exposure three to five times, should be used in conjunction with these plates. (See Volume II for full description and methods of handling color sensitive plates and filters.)

661. Background

Background. The background is a very important factor. A white one should be employed when the majority of the subjects or objects photographed are dark, while if they are light a black ground should be used. These two extremes will be all that is required, and their method of use and application is described in Volume III, Chapter XX (Lesson Xiii. Modeling Rembrandt And Shadow Lightings) (Lesson Xiii. Modeling Rembrandt And Shadow Lightings), Floral Photography.

662. Support For Camera

Support For Camera. A tripod will answer every purpose for supporting the camera, yet a regular copying board, similar to the one described in Volume V, will be found a more satisfactory piece of apparatus for many still life subjects, and especially in the study of botany, but for all-around work the tripod will answer every purpose.