Q. How do you get the right perspective in pictures?

A. You can change the perspective of your photos by using a telephoto lens or by enlarging part of your negative. It is better to use a telephoto lens, because that will give you a larger image on your negative, resulting in a sharper blow-up.

How long a telephoto you need depends on the effect you want. Lenses of over 200 mm. focal length are heavy and expensive. A substitute is to use a teleconverter, which doubles the size of the image. This device is light and completely satisfactory for that occasional long shot. Binoculars can also be adapted to fit on your lens to give you that tele look.

If you do not have any part of this equipment, you can still get tele effects by blowing up the distant-scene part of your negative in the enlarger. For this purpose, use a fine-grain film, since you'll be using only a part of your film area.

A simple way to preview the effected you'll get by enlargement is to crop the area of the photo with two L-shaped pieces of cardboard. By enlarging or reducing this framing you will be able to visualize how your finished enlargement will look.

Q. How do I get the right exposure for a person silhouetted against the sky?

A. Move in close enough to exclude the sky and take a meter reading. Then move back to your original position and shoot the picture at this exposure. If you subject is too far away, take a closer-up meter reading from the back of your hand held at the same angle to the light as your subject and shoot at this reading.

Q. What filter do I need to get those wild dark-blue skies in my color pictures without changing other colors?

A. You'll need a polarizing filter. First determine the axis at which it will block out glare by looking at a reflection through it and slowly turning it around until the reflection is eliminated. Then holding it in that position slowly turn around while looking at the sky to determine the direction from which it will block out sky glare. Position you model or frame your scene in this direction and shoot with the filter on - and don't forget to allow for the filter factor by opening up 1 1/2 stops.