Q - What's a "normal" focal length for a 35mm camera and a 2 1/4?

A - This keeps coming up. The normal focal length is equivalent, or close to, the diagonal distance of the film size. This would make a normal lens for a 35mm camera 50mm, and for a 2 1/4 x 2 1/4, 80mm. But today so many photographers have gone to the wide-angle that a 35mm lens on a 35 camera seems normal.

Q - Is there an easy-to-read and understand encyclopedia of photography? I'm tired of looking all over for bits of information.

A - Yes. Finally Eastman Kodak has gathered all those "how-to" books and tech manuals together and put them into one basket, called the "Encyclopedia of Practical Photography." It's being published in a 14-volume set through November of 1978 by Eastman and the American Photographic Book Publishing Co. (AMPHOTO).

The first volume A to Ba, is now available in book shops and photo stores for $11.95. It starts with "A and B Roll Movie Film Editing" and bows out with "Baby Photograph." In between are sections on advertising, aerial and animation photography (on the practical side), and aberration, actinic and anamorphic (on the technical). Also included are brief biographies of people like Abbe, Ernst and Abney, and Sir William de Wiveleslie, known only by few, and Adams, Ansel, of whom everyone has heard.

At the end of subject categories there are helpful lists for further reading as well as cross references, so you can go deeper if you feel the need. For the practical-minded (and what photographer isn't?), there are a lot of cute tips on how to solve picture problems that may have driven you up the wall.

For example: To keep fish from swimming out of focus range in an aquarium, simply insert a piece of window glass to confine the swimming subjects to a shallow focus area. Or to keep copy flat when it is valuable and you don't want to stick pins into it or tape onto it, use a piece of weighted cloth tape to hold it down.

By all means, take a look at this first volume of the "Encyclopedia of Practical Photography." If you don't want it - well, Christmas is coming up, and your favorite photographer might.