Updated: 01/01/2016


Technical Addendum

 

 

 

Digital Camera

Adjustments

 

Although camera manufacturers use different terminology for camera adjustment functions, the most common DSP (digital signal processing) camera controls adjusted through the camera setup menu are:

The automatic iris As the name suggests, this manages camera iris or aperture to provide proper CCD exposure. Often, this automatically manages both the camera's electronic gain control and the camera's shutter speed to achieve maximum control over exposure.

The white balance control adjusts for color temperature variations. There are usually presets at 3,200K, 5,600K, and 6,700K.

The contour or detail enhancement function adjusts edge contrast between areas of different levels of contrast in a picture. You can only go so far in enhancing detail in an image without creating disturbing artifacts. For example, the images below show a normal picture on the left,  and overly enhanced version of the same picture on the right.


This adjustment may be further broken down into skin detail, which reduces the sharpness in skin areas (giving subjects a more youthful appearance — see examples below), and soft detail, which reduces excessively sharp detail that may be objectionable in areas of high contrast.

The knee manages the highlight compression of the video signal. Generally this is further broken down into subdivisions that further control the highlight rendition.

The gamma function controls the general brightness (luma or luminance) and the contrast curve.  This control allows an operator to set the "characteristic curve" of the camera, or the way in which it reproduces various tones along the black-to-white scale. The term gamma has slightly different meanings in film and in video.

The black gamma controls the contrast and detail in the shadow and black areas of the picture. This may be further subdivided into a black stretch control for enhancing shadow detail, and a black press function that increases contrast.

The matrix function manages the hue and saturation of the video to reproduce the most accurate color.

There may be a diagonal detail control that increases the contrast in the diagonal parts of the image. This serves to increase sharpness in these areas while reducing objectionable color moiré patterns.

Two  common DSP features include a zebra pattern (or zebra stripes), which is a black and white camera setup pattern that can be set to appear in areas of the picture that exceed acceptable brightness levels, and a SMPTE color bar generator, (note example on the right) used to adjust video equipment

Modern digital cameras have skin enhancing setup options available that can reduce, but generally not eliminate, the need for makeup. In particular, they can appreciably smooth out wrinkles and conceal minor blemishes. Some video engineers may not be anxious to use these techniques, since they degrade optimum video sharpness, color, and quality. Note the difference between the two photos below.


A more complete list of the possible camera adjustments can include:

  1. frame rate
  2. shutter percent
  3. gain
  4. gamma, pedestal
  5. black stretch
  6. knee point
  7. knee slope
  8. dynamic level
  9. saturation
  10. color correction
  11. white balance
  12. matrix table
  13. filters
  14. camera setups
  15. memory card setups
  16. number of users
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