tion at the New York World's Fair, 1939, shows Kodaclirome 35mm. film l" x 1^4" projected to 17' x 22' with perfect color rendering, clear definition, no grain, and a remarkable three dimensional effect. It is obtainable in 35mm. rolls and several sizes of cut film. Development at the Eastman plant in Rochester, New York, is included in the price. "Dufay color film, in both roll and cut film types may be used with almost any camera and developed anywhere. Lumiere and Finlay plates are used chiefly in lantern slide size or larger and are not difficult to develop.

Films and plates for black and white photography are too numerous and varied to mention. The manufacturer or an experienced photographer should be consulted as to the one best suited to your work. .

• 3.Smm. Kodachrome him is also developed at Kodak, Ltd., Wealdstone. Middlesex, England: Akt. Fabrik, Friedrirhshapener Strasse 9. Kopenick, Germany; Kodak- Pathe, S.A.F., Avenue Victor Hugo, Sevran, France.

A. How Various Lenses Are Constructed and the Approximate Speeds That Result.

1. It is easy to see why the price increases with the speed.

2. The illustration does not indicate the

greater size of a fast lens, but it does suggest the added weight.

Eastman Kodak Co., Rocheiter. N. Y.

The lens is the camera. In choosing a lens, sharp definition and good color correction are important. High speed is of value for only a few special uses. A set of lenses with different focal lengths is most advantageous.