Q. What is the REAL difference between using a discount photo developing service and the more expensive manufacturers' processing?

A. In most cases, there's not much difference. I've had manufacturers lose rolls of film and I've had drug stores do the same. In all fairness, the losses were few and far between.

In many cities most of the processing is done by large organizations that can handle service logistics. Occasionally you find that one chain of stores has its own processing facilities, but most do "farm them out."

If an organization is big enough to handle processing for several chains, amounting to dozens or even hundreds of stores, it will have the capability of doing lots of fast, quality work.

Shop around, try several. Ask the store managers who processes their film. Do some comparison shopping. Also, watch for processing specials. I never rush film in immediately. I check for specials first.

In many areas, one-hour color developing and printing stores have opened, mostly in shopping centers. They're a bit more expensive, but generally do high quality work. FOOLING THE CAMERA

Q. Somebody lied to me! When I bought this camera I was told it was fully automatic. Now I've gotten the pictures back from my skiing trip and many of the best action shots are weak-looking and light. The ones inside the lodge are OK, but the slopes' stuff stinks. What happened?

A. Don't get mad, get some advice: There are situations where there is just too much light, especially for some of the automatics. If you use a fast film, snow scenes and beach scenes can overwhelm your exposure system.

So, you must "lie" to your camera.

If you're using ASA 200 film, move your ASA setting to 400. This will allow less light to be available to your film. If you're using ASA 400 film, move the ASA setting to 800. Just don't forget to reset your ASA when you get out of these super-bright situations. PHOTO CAREER

Q. I'm a high-school junior and am very interested in becoming a news photographer. How should I prepare?

A. The main thing is to take pictures. You never can make enough. Just be careful that you don't "burn" film. Learn from doing.

What to shoot? Anything that moves, and most things that stand still. Work for your school newspaper, year book and/or literary magazine. Take portraits and shoot sports, meetings and any other situations that come up. In college, you must do the same thing. (Oh yes, today it's almost mandatory that you have some college background). Plan to beat a path to the door of your local newspaper. Become a "stringer" and start to collect those printed credit lines.

Stay up to date with technical developments; the tools of your trade are changing rapidly.

And be sure you do some processing and printing, both in black- and-white and color. There are some great teachers around.