Q: Often when I photograph my darkskinned friends they are underexposed and with flash I get greasy- looking high-lights. How can I overcome this problem? A: Dark skin requires more exposure than light. Technically, each person's skin has a different degree of light reflectivity, for which the built-in tolerance of the film compensates. But with extremes such as a face in shadow or darker than the average skin, underexposed results.

A meter does not necessarily give the right information to correct this underexplosure unless it's properly used. For example: If a person is standing in the sun with his or her face in shadow, the light shinning into the lens or the highlighted background will cause the meter reading to average in the light and shadow areas, resulting in underexposure on the face. The very same phenomenon happens when a dark-skinned subject stands against a light background.

The way to compensate for this averging quality of the meter is to move in close enough to exclude the light areas and take the exposure setting directly from the dark skin. As with the sun in back of a light-skinned model, the exposure can vary from one to two stops from the over-all scene. This would mean that for subjects back-lighted with the face in shade, or in the sun with dark skin, the setting could change from f/8 to f/5.6, or even f/4.

With flash, underexposure with glary reflected highlights occurs because the dark skin tones absorb more light and reflect less. Again, the solution is to open up a stop or more, depending on the darkness of the skin. Q: Because of my deteriorating vision, I am unable to secure as clear pictures as I used to get when I could see better. I have a precataract condition that's worsening, yet I hate to give up taking slides, which are such a source of pleasure to me and to the many organizations and school classes who depend on me for "free" entertainment and information.

I'm conscious that my slides don't seem as sharp even though they look good in the camera. Also, on my last trip to Morocco and Tunisia, many of my slides were overexposed, which was an additional disappointment. I have a 15-year-old Minolta SRT 101 with a Rokkor 1:28 lens.

My question is: Should I purchase another camera -- one requiring less adjustment before snapping? Or what other suggestions do you have? A: Your problem, even though more extreme than usual, is rather a common one with advancing age. The eye no longer focuses sharply, either far or near, and funny things begin to happen as you look through the viewfinder. There are solutions to this problem.

One is buy a diopter fitting for the camera eyepiece. These come in various strengths and simply screw into the viewfinder. Go to a reputable camera dealer who has a variety of diopter eyepieces and try looking through them -- don't use your eyeglasses when you test, because the fittings should approximate the strength of your glasses.

Or you might exchange your present f/2.8 lens for a faster one, such as a 1.4. The faster lens will give you a brighter, clearer image on which to focus. This is because with an SLR (single-lens reflex) camera you are looking at the image through the lens, and the bigger the lens opening the brighter the view.

Of course, the problem may also be the film you're using. A high-speed daylight film, so popular today, just doesn't have the resolution that Kodachrome has. Perhaps those sharp slides you remember were taken before the new, faster, softer emulsions became a fad.

If you want critical sharpness, try Kodachrome 25 or 64 on your next trip out. You'll be amazed at the difference. Of the two, I suggest the 64 as a good all-round film since it's a stop and a half faster than Kodachrome 25.

If none of these suggestions works for you, I'd strongly suggest that you're an ideal candidate for one of the completely automatic cameras that focus, set the exposure and even advance the film. You may look down on all this automation if you've done it yourself, but there is a use for this modern techology and I, like many other pros, use automation when needed. The picture is still your own even if the camera becomes a full photographic partner. A word of caution if you go the automatic route: Be sure to check that the batteries are fresh, and if you plan a long trip take an extra set with you. Q: What schools teach photography and television camera work? What related subjects would be required if I attend a fulltime school? A: A good over-all survey of the photographic field and its possibilities is in a handy paperback book called Opportunities in Photography , by Bervin Johnson and Fred Schmidt, published by Ziff-Davis Publishing Co. of One Park Avenue, New York, New York 10016. The book costs $4.95 and has a discount school price of $3.71. Not only does it cover all the job prospects, it also has an appendix of photographic schools.

An even more complete listing of more than 800 schools is in A Survey of Motion Picture, Still Photography and Graphic Arts Instruction , available in most public libraries or from Eastman Kodak, Department 454, 343 State Street, Rochester, New York 14650.

I would suggest that you write to the schools that appeal to you from these listings, asking for their brochures that detail their courses of instruction and costs. Besides attending a school of photography, you should also try your hand at it by looking for a summer job with a photographer or a photo studio. Many photographers have gotten started in just that way -- the apprenticeship route.

To be successful in photography you need to be strongly motivated and visually oriented. A good way to develop artistic appreciation is to visit museums, study photography and movies and practice using an analytic eye -- determine what you like and why, so you can develop a personal point of view.