Image quality is rather hard to define.
It means different things to different people. So much depends upon a
photographer's personal standards, his or her expectation based on
experience and the purpose for which a picture is taken. Quality that
may seem excellent to the average hobbyist may fall far short of the
mark for a professional photographers dealing with a national
advertising campaign. However, the following points cover the most
important aspects of image quality for anyone. If they are constantly
kept in mind and improved upon, quality will automatically get better.
Below is some tips of controlling the camera lenses, sharpness,
exposure, ligthing and composition.
Sharpness - Unless a blurred
effect is wanted for some reason, a photograph should be sharp, clear
and full of detail. A number of factors must be properly coordinated to
achieve this kind of quality, the most obvious of which is accurate
focus. This factor may depend in part on having a lens that is clean
and free from dust and greasy smudges and a viewfinder that is equally
clean. If you can't see your
subject clearly, you can't focus accurately. Then, too, the camera and
lens must be held motionless during the exposure, and the shutter
speeds should be high enough to stop any possible movement in the
Exposure - Incorrect exposure can do almost as much to undermine image
quality as lack of sharpness. With the excellent auto exposure system
built into today's cameras, there wouldn't seem to be a problem getting
accurate exposures. But for these devices to work properly, you must be
sure that the camera battery is good, the correct shutter speed and the
manual override feature (if any) is properly set, and the exposure
control is turned to automatic. If you are using flash, be certain the
shutter is set to the right speed for synchronization.
Composition - To be of high quality, a picture should be composed in a
pleasing or attention-getting manner. First, make the subject large
enough within the frame. This involves camera to subject distance, the
proper focal length lens, or both. In addition, the subject should
relate to its surroundings in an effective way. Here we are concerned
with camera angle, distance, and perspective. Experiment with these
various factors until the image looks best to you. Another important
point is to try to eliminate anything in the scene that does not
directly contribute to a picture's effectiveness.
Lighting - Although not an optical or mechanical consideration,
lighting is an important picture element in both quantity and quality.
Harsh, contrasty lighting may be all right for a few subjects, but
completely unsuitable for others. The same reservations apply to soft,
shadowless lighting. Furthermore, any subject los different when the
direction of the light is changed - from the front to the side, for
example or from a high angle to a low one. Always try for the type of
lighting that best serves your subject.
Freedom from defects - Even if careful attention is given to all of the
above points, image quality will still be poor if careless defects are
allowed to creep into the picture. Dust spots, scratches and chemical
stains will spoil otherwise excellent pictures unless care and
cleanliness are part of every picture making step.