Many photographers, both amateur and professional, feel the price-pinch as the cost of cameras and film keep going up while purchasing power goes down. The amateur may look calculatingly toward his camera and wonder if it can help pay part of the freight.

And so there's been a rash of new books, newsletters and workshops designed to cater to the need for cash. Some of these efforts are sincere, and some are rip-offs.

Readers of this column have asked for advice on how to turn a hobby into something more substantial, or how, through the sale of pictures, they can help defray the expenses of a trip. Others have raised the question of a tax exemption to help offset the cost of photographic gear. Let's take a look and see what the reality is.

Ron Engh, a professional photographer who publishes a bi-monthly photo-letter listing stock photo markets, says the majority of his clients are amateurs: they're "plumbers, farmers, salesmen, teachers, doctors and housewives" -- all with a talent for photography. Over a thousand of these picture enthusiasts subscribe to his publication listing photo requests from the editors of books and magazines. (A courtesy copy of Photoletter can be obtained by writing to Photoletter, Osceola, Wisconsin 54020.)

A step up to the pro scale is Associated Photographers International, an organization of 15,000 free-lance photographers in the United States and other countries. A monthly newsletter spreads information and inspiration among the members, who wish to improve technical skill and acquire pay-off business acumen. (Write A.P.I. Publication Office, 21811 Sherman Way, Suite 101, Canoga Park, California 91303 for information).

These two publications may offer suggestion, but neither they nor any other group can do it for you. In photography, as in any creative field, you have to go on your own -- and the competition is tough.

A good survey of the field of photography, its possibilities, problems and profits, is outlines in a book called Selling Your Photography, by Arie Kopelman and Tad Crawford, published by Saint Martin's Press, 175 Fifth Avenue, New York 10010. At $13.95, this book is well worth the price if you're serious about stepping into pro photography. It tells you how to find the markets, gives a full business guide to pricing, contracts, taxes, insurance and the legal aspects of coypright, releases and the risk of lawsuits.

What are the kinds of pictures that sell, and to whom?

It depends on the quality. Just because your family is impressed is no reason the editor will be. They will compare your shot with thousands of others -- so it better be that good.

The way to tell how good your pictures are is not to listen to friends and relatives but to be objective. Compare your shot with what you see published; leafing through any magazine will give you samples. If this comparison reassures you then go ahead and try sending it in for publication.

A good way to get the best results is to picture the subjects that mean the most to you. If the subject is kids, then concentrate on them in all their varied actions and expressions. If it's pets, then learn how to attract and hold their attention. And if you're partial to pretty pictures of scenery and sunsets, shoot as many as you can and try to improve each one.

Although the competition is stiff, at times anyone can come up with a superb scene or a cute candid. That's the democratic aspect of photography. Sometimes just because you're there at the right time an unusual picture can be taken that the world's best photographer couldn't take -- because he is she wasn't there. And this is another reason you can compete with the pros. If you have good 35-mm equipment and know how to use it properly and develop your eye, you can make a unique statement -- just because you have your camera with you.

The new copyright law passed in 1978 recognized the uniqueness of a photograph. Every picture that you take can be copyrighted -- even if you stand in the same spot and machine-gun a scene. Each click of the shutter is in some way a different scene. With the aid of this law you retain all rights to your photograph and can sell "use" rights only. That means you can specify to a publication that you are selling one-time use rights for a fee after which your photographs is returned and you can sell rights again -- and again.

The ability to re-sell a photograph is how you can get full value from a unique scene. Some pictures have been sold over and over again -- and returned to the photographer. This means that if you shoot one prize-winning picture you can repay all your equipment costs in a fraction of a second.

So whether you're a hobbyist, advanced amateur or practicing pro, the camera in your hand can with a lucky click earn enough to pay for itself -- if you just keep on trying.