Q. How can I get around the rising cost of film and processing? I can't take as many pictures as I used to. A. Everyone has the same problem. Typical of the rising cost if Kodak's 17 percent increase this year. But here are six ways to save on film and processing:

Watch for sales. Often a brand of film is sold as a loss-leader to attract customers. Sometimes you actually can buy film for less than the retailer's cost.

But in bulk. Most stores will give a discount if you buy 10 rolls or more.

Even if you use only an occasional roll, the rest can be stored in the refrigerator. Color film will keep in the cold at least until the expiration date and almost indefinitely if stored in the freezer. But it needs time to warm up before use: if refrigerated, it needs several hours; if frozen, overnight.

Roll your own -- not as hard as it may sound. Film loaders on the market hold 100 feet of film which can then be wound into reusable film cassettes. Since the length of a 36-exposure roll of 35mm film is about 5 1/2 feet, a 100-foot roll gives 18 rolls. Photo magazines like Popular Photography and Petersen's Photographic advertise sales of both loader and stock film for about what you'd pay for the same number of factory rolls.

Try other brands. Sure, you may be sold on a certain package; the manufacturer counts on this for repeat sales. But many independent brands such as Snapp's Jack Rabbit, Fox Print, Carl's and Photo Corral are all the same 3M product. In fact 3M film is sold under 40-odd labels; all of them are standard E-6 for slides or C-41 for negative color.

Skip fast processing. You can save up to half the cost of film development and printing by using the normal rather than the speed-up processing. If you don't need the service, why pay for it?

Another way to save on color prints is to order the prints at the same time the negatives are being developed.

Mount your own pictures. You no longer need an expensive hot-mount press for exhibition prints. There are sprays like Vacumount and Scotch Photo Mount (both 3M products) that can be sprayed on the back of the print and then pressed onto the mounting board by hand. (If you want to be sure of good adherence, spray the back of the print as well as the board.)

As you shop around, you'll find other ways to save on film costs. The film industry is big ($2.1 billion in photo-finishing sales alone in 1979) and highly competitive. Fotomat plans to enter the independent film market and Sakura products; with this added to the big three of Kodak, Fuji and 3M, competition for consumer dollars will increase. Q. At a historic re-enactment, I tried to photograph a cannon firing. One of the cannoneers told us to compose, and open up our shutters, then hold the shutter open until the gun went off.

What he didn't tell us was about the minute or so deafness from the blast.

Despite my body's violent recoil at the noise, I did get a picture of the flame erupting from both the front and the touchhole in the rear. The only problem with the picture was the off-color skin tone of the cannoneers. Next time I'll use a longer lens and wear earplugs. A. The earplugs and longer lens are a good idea. For better skin tones, Type B (Tungsten) film is color-balanced for the reddish glare of cannon fire.