Days are getting shorter, so this is a good time to focus our own light on the scene.

Flash is easiest but doesn't capture the atmosphere. Try normal room lights, lamplight and candlelight for a more artistic look. With today's fast films and a little friendly help from your lab, you can shoot with available indoor light almost as easily as with sunlight.

What makes thes low-light picutes possible is a laboratory technique called pushing, which is simply a fancy name for over development. It consists of developing longer in the regular developer for black and white or adding development time to the first developer in the color process.

Pushing has been made much of recently in popular magazine articles. It seems that each new story outpushes the last. But it isn't a new idea at all.

Photographers used this technique when they were shooting by the seat of their pants. They would say, "This scene looks a little dark, so I'll expose longer." Then they would inspect the film during development and decide just how much longer they needed to develop to correct for their underexposure. In other words, they were pushing their film by overdevelopment.

Today, however, all the guesswork has been taken out. We do it by the numbers -- ASA numbers that is. (ASA stands for the American Standards Association rating of film sensitivity.)

If the film is rated at ASA 400, we can change to ASA 800 on our film speed-setting dial and double the sensitivity, or to ASA 1600 and make it four times as fast. Of course, we're not changing the film at all; we're just playing with numbers.

But these numbers work. All we have to do is mark the new number for the lab, or for ourselves if we do our own developing, and increase the developing time accordingly.

Most black-and-white developers have the various ASA development listed on the instruction sheet, and there are additves, such as Factor 8, that can be mixed with the solutions to increase the ASA.

Color developers work the same as for black and white, but in their case, only the first development time is increased for pushing. The rest of the process remains the same.

Conservative Kodak will double the ASA of all E-6 process color films on request but they will not monkey with their color negative Kodacolor and Vericolor, explaining that these can be corrected for either one stop over or under exposure in the color prints.

Photo Specialities, BOX 60445, Los Angeles 90060, claims that they can push Ektachrome, Kodacolor and even Dodachrome three stops and you won't be able to tell the difference from normal processing. They make an added charge, as does Kodak, for this special handling.

A tip for those of you who do your own E-6 developing is that Kodak recommends an additional two minutes in the first developer for doubling the ASA, and an increase of five minutes over normal for a two-stop difference (that is doubling the ASA twice.)

How far you push your film depends on how good a gambler you are. The odds keep changing as the numbers go up.

Some of the factors you have to juggle are increasing loss of shadow detail, globs of grain, color shift and reciprocity failure -- which means the film just poops out. When you start pushing film beyond a certain point, you're on your own. But if you hit, you can come up with a winner. Q. What's the best way to take color photos of a fashion show? Should I use flash or the lighting that's there? A. The choice will depend on how much light there is. Ask beforehand what the lighting plans will be. If you can't do this, then go prepared to shoot either way.

Take alsong some ASA 400 color film for the spot-lighting and a flash attachment in case the light is too dim. If you have a choice, and there is sufficient light, shoot with the fast film to preserve the atmosphere of the show. Choose a spot from where you can shoot as the models are coming toward you rather than across, so you can stop the action. Also watch for that instant when they hold still while showing the costume for motion-free shots.

If there isn't sufficient light, an auto-flash unit that adjusts the light for the distance is best. It will permit you to shoot while the models are in motion. Q. How can I get the correct exposure on a candlelit scene with my through-the-lens meter? A. First compose your scene in the viewfinder just the way you want it with the candleflame in the picture. Then shift your viewpoint so that the flame is not in the picture and take a meter reading of the scene. Use the setting shown by your exposure meter to shoot the original composition including the candle. Q. What's the best equipment for closeups of flowers? A. You can use closeup lenses, bellows, extension tubes and macro lenses. For sharpest closeups use the fixed-focus macro lenses. I like the 55mm Micro-Nikkor, but with the 105mm Micro you can move back farther. Bellows extensions are unwieldly: you really need a tripod. With a micro lens, be sure it has a feature that automatically adjusts for the closeup exposure difference.