Multi-vision filters can increase your pleasure by multiplying an image three, five or six times.

These screw-on lens attachments are not really filters at all, but lenses with prismatic surfaces that form individual images.

With a five-sided or six-sided multi-vision lens, a picture of the moon becomes a galaxy of moons. Photograph fireworks and they fill the sky.

A manufacturer called Hoya has multivision lenses in four varieties. A three-parallel face lens produces three side-by-side images. Another three-face splits the image into three sections, and a five-and-six-face prism keeps the original image centered but also reflects an additional four and five more repeats around the edge of the frame.

These attachments work best with your normal 50mm lens, but you can vary the images in the center of your picture frame and the telephoto will spread them farther out to the edge.

A feature of these multi-vision lenses is a double-ring mount with a crank handle: By turning the handle you can change the position of the images to produce the best composition.

There are a number of techniques you can use with these devices.

You can multiply the image. For this adaptation it's best to use a strong central figure in your composition and a plain background.

Outdoors, take a low camera angle to silhouette the subject against the sky. You also can use a plain wall, indoors or out, or a very distant scene as background.

For variation, choose a slower shutter speed than usual (1/30th of a second is good) and rotate the ring during the exposure. (Be sure to compensate for the slower speed by stopping down the lens.)

Night shots, especially with colorful neon lights, also can produce dramatic effects. For these, try both the fixed focus and also the rotation of the ring.

The fly in the ointment is that because these are precision-ground lenses, they're not cheap. For starters, try out the lenses in the camera store before you buy, and decide which effect you like best.

Q. You wrote about sending a note along with photo contest entries granting certain rights and stating that you want the original returned.

Can you do that when the contest rules state specifically that everything becomes the property of the contest sponsor?

Can you depend on your request being honored or even read?

Some contest rules state that the photo submitted will not be returned. You are not even told to send return postage. Would you enter such a contest?

A. The new copyright law categorically states that the photographer owns the picture that he or she takes unless they are an employe or have entered into a work-for-hire contract.

As legal owner of the picture it's your option whether you want to sign your rights away. I can't speak for the contest promoters: Some are legitimate and some are ripoffs.

But you sure can send your own contract. It's a good idea to send return postage if they don't agree and ask for a signed copy if they do. I don't know if they will honor or even read your request-but if they send back a signed piece of paper then you have a contract.

If the contest ststes that the original will not be returned, then I wouldn't enter that contest. By original, I mean the original transparency or negative, not a print.

In summary, use common sense in entering contests. If the prize is worth the gamble, enter; if not, don't. But you should be aware of your rights-even if some of the contest promoters aren't. :FOR YEARBOOK STAFFS-There's a new photographic "Yearbook/Newspaper Calendar" to help high school staffs produce a better product. The calendar gives a day-by-day reminder of what needs to be done and features a monthly photo with how-to-do-it information. It corresponds to the school year from September 1979 through August 1980.

The "Yearbook/Newspaper Calendar" is available for $6.25 from Box 210, Los Olivos, Calif. 93441.