Q - I have some old snapshots which I want to copy. They are faded and some of them have yellowish stains and restore contrast to the pictures?

A-You ins and restore contrast to the pictures ?

A - You can eliminate or at least cut down the yellowish stain effect when copying by using a yellow or orange filter. Match the filter color as near as you can to the color of the stain and don't forget to allow for the difference in exposure. Contrast can be increased when copying faded prints by increasing the development time of the negative or using a more contrasty paper when making the print.

Q - About the new copyright law that guarantees the photographer the rights to his picture even if permission for its reproduction has been granted. What effect will the new law have on photo contests the require the original negative or slide and exclusive rights to the winning entry?

A-I've obtained a ruling from Robert Cavallo, the legal representative for the American Society of Magazine Photographers (ASMP). His advice is that when you send in the slide or negative it should be clearly marked with a copyright symbol, your name and the year. In an accompanying letter state that you are granting certain rights for contest promotion only and that you want the original returned after such use. Include a stamped, self-addressed envelope. If it's a legitimate contest they'll go along - if not you're taking a chance even entering.

Another way out is to send a dupe and state that in case you win the original will be available.

In any event remember that the copyright law guarantees that the photograph is yours and you should control how it is used.

Q - I have a Kodak Retina camera which you mentioned was a "classic." How much would it be worth to a collector?

A-By classic I meant its usefulness as a trip camera because the lens folded back into the camera body.

The Blue Book Price Guide published annually by Photographic Memorabilia, P.O. Box 351, Lexington, Mass. 02173, lists various models of the Retina as having current market values of from $40 up to $125 depending on the model.