Q - As a teacher, I often find myself wishing I could make slides of photographs in magazines to show my classes. How can I do this and what equipment will I need?

A - The simplest way is to use a closeup lens over your regular camera lens, so you can focus in closer and fill the frame with your copy. A good light source is a small strobe because it has a color-corrected, constant light output. The trick is to take the strobe off the camera. You can do this with an extension cord, and position it off to the side to avoid light reflections.

Keep your light always at the same distance and your exposures will be the same, regardless of how near or far your camera is from the copy. You can determine the f-stop by dividing the guide number of the strobe you're using by the distance between your light and the copy. If your guide number is 30, and your distance is two feet, your f-stop will be f-16.

Q - I am a free-lance photographer, and recently I sent a photo-story with original transparencies to an agency in Rome, Italy. It hasn't returned my material in spite of numerous requests. Is there any organization that could help me or advise me as to how to recover my material?

A - Associated Photographers International, Box 206, Woodland Hills, Calif. 91365 may be able to help. They have members all over the world and may be able to follow up your Rome agency contact.

You shouldn't send original transparencies to any market unless you know from previous experience that it is reliable or until you have a purchase order for a sale. If you want to speculate, it's far better to have dupes made and send these with the understanding that the originals would be available when a sale has been confirmed.

Q - Twice I've taken rolls of film with my Kowa 66 camera that had blank film in the middle of the roll even though it cocked as if it were taking a picture on all frames. What's wrong?

A - Camera ills can't be diagnosed long-distance. Take your equipment to a qualified repair shop or to the manufacturer. The problem could be any number of things, but but from your description, it could be the film advance mechanism.