Q. I tried, with some trepidation, your suggestion about shooting color slide film through a red filter. To my surprise, I was quite delighted with the results.

I took some pictures of the sun low on the horizon causing sparkling lights on the waters of a reservoir. The red cast gave a strange and almost eerie look to the scene. I had no trouble with exposure, since both my SLRs have through the lens metering.

Now I'm interested in some other special effects. What have you to suggest?

A. There are some great ways to go, but first a word of caution: I assume that you have been able to get exactly the results you want in non-special-effect shooting. Whenever I become involved in special effects, I always make a frame or two in the normal mode, properly exposed and without filters. This gives me a way to compare and see just how special the new effect is.

For still pictures, I don't try for "Star Wars"-type animation. I try for something different, out of the ordinary, but always pleasing or interesting.

Recently I have been testing the Schneider B + W series. I tried red and gray gradation filters (top dense and fading toward the center and clear at the bottom), some neutral density filters, a Spectra filter, a soft-focus filter and, of course, a polarizing filter. I also used my Tiffen enhancing filter. Everything was shot on cameras with through-the-lens metering systems, so exposure was not a problem.

The red and gray gradation filters were great and lots of fun. The red top gave some added drama to both sunrises and sunsets. The gray-topped filter was wonderful for toning down the bright white sky on a super-clear, bright day. It balanced sky and water perfectly.

My experiments with the Spectra filter (made to give a rainbow effect around light) were not successful outdoors. I found that I needed a bright point of light to get the best results. Streetlights and bright reflections work well.

The soft-focus filter was terrific. The center of the picture is sharp, but the edges drop into a misty, almost supernatural look. This filter takes some getting used to, but I was pleased with the results, especially at dawn, in low light.

But there are other ways to go besides using filters: Try some low-key portraits. Darken a room, put your subject in the middle of it, put your camera on a tripod and set the shutter on bulb or time. Open the shutter and with an ordinary flashlight "paint" the face of your model with light.

Then, while you have this set up, try some lighting with just a camping lantern or an aluminum shop light. Use a slow film and shoot in black and white as well as color. Low-key portraits lend themselves to black and white.

And, one of my favorite stunts, use your slide projector as a light source. Make a cardboard tube to fit over the lens and you have a spotlight. Then, while you're working with your projector, try projecting a slide onto your subject. I have some special slides I shot just for this exercise. You'll be surprised how strange a person's face can be with a scene superimposed over it.

Q. I recently inherited the job of photographic expert at my office, probably because my boss knows I have a camera (a Minolta Freedom 90). I have to copy documents, pictures and charts on slide film so they can be projected at sales meetings. We have a single-lens reflex camera with a 35-70mm zoom macro lens.

The problem is that I don't have a budget for fancy equipment. This project is important enough to spend a little money, so please, some inexpensive advice.

A. My personal feeling is that if this is a long-term project, you should spend a little money on a proper copying stand. For as little as $250 you can get a solid stand, with lights, that is durable and will last a long time.

That failing, you can go another way: Mount your SLR on a tripod and make your own copy stand easel. A flat board, such as a kitchen cutting board, works well. Find a spot near some windows and mount the board to a wall or other vertical surface. Attach your documents to your easel with removable transparent tape.

Set your camera on macro, focus and shoot. Focus is critical, since you probably will be shooting at slower speeds. In fact, I recommend you use a cable release to ensure camera steadiness.

For film, I would suggest you use either Fuji Velvia, Kodak 100HC or Agfachrome 100. Be sure that you bracket exposure, since daylight intensity varies from hour to hour.

Write Carl Kramer c/o Weekend, The Washington Post, 1150 15th St. NW, Washington, DC 20071.