（轉貼）攝影技考篇 - Color

What's color?
1. Does it signify something ideological?
2. or is it a form of identity?
3. or is it an expression?
4. or is it an expression?

Actually, color is a science.
‧ Even as science, there are also different “systematic approaches”:
‧ For example, you can see it as an energy path going from A to Z: If so, the components are:
  1. The originator.
  2. The modifier.
  3. The receptor.
‧ Or you can see it as cause and effect, then it can become:
  1. A physical science.
  2. A psychological science.
  3. The applications.

Color Sensitivity:
Color depends on the wavelength of light and on the way in which the human brain has become accustomed to interpret it.  Redness or Blueness are simply the wasy in which we recognize specific wavelengths.

B&W film or B&W digital photo does not actually show colour in this family way, but it does record all the dame wave lengths.  A B&W print displays the colours as different tones of grey.

Non Chromatic Family: Grey Scale B&W Photography

Actually, color can't be without light and vision. For example:

‧ In fact, we do not sense all color equally.
‧ For example, we have between 14 to 20 times less blue cones than the other two colors depending on which part of the eye.
‧ That means we are less sensitive to blue compare with the other colors.

Another example:

Vision will shift from a bluer tone to a browner tone as you grow old. It is a gradual process and your brain tries its best to compensate for that.

To compare with color and B&W, there would have different sense:

Color Sensitivity

B&W Sensitivity

Another Example of Color Sensitivity:

B&W picture occupies a special and unusual place in photography.  B&W photo gives surrealistic imagery, and able to be treated as means of artistic expression.
Also, it converts from real life into different grey scales wihch is known as grey tones.  One of the most basic techniques in controlling tones is to control the exposure.

Basically, in photography, we've zone system to control the contrast and color shape.  What's zone system?
Zone system is not a system for exposure calibration.  It is a system for controlling value reproduction with the result of printing in mind. A zone therefore is a print value or zone value you aim to achieve by proper exposure and development.  The key here is that it is all about reproduction and previsualization.  By using exposure, you place the subject in any zone you want and the rest of the scene will fall into place.  If you are using a photo-chemical process, you can also control zone placement
by controlling development. (Contrast in highlight will increase with increase development time, WHICH INCREASES THE DENSITY OF THE NEGATIVE, that
means moving highlight up by one zone or more. The reversal of pull development is also true.)

Otherwise, Zone system was invented by Ansel Adams for fine control over exposure, which is best suited to the photography of static scenes.  It assigns all the levels of brightness in a scene, and all tonal values, to a scale of ten steps.

VIII Highest Zone
IX Untextured White
VI Caucasian Skin
X Nearly White

There is a simple method to take a good Zone System picture

1. Make a quick sketch for recording the image
2. Measure the exposure value for each zone in candles-per-square-foot (c/ft)^2, by assuming a film speed of ASA 100 and a shutter speed of 1/125
3. Decide subjectively what are the important areas of the scene.  The immediate foreground is critical, for while it does not cover any significant detail to merit Zone III
4. By placing the foreground in Zone II,  everything will fall in its own zone. The contrast range in the subject is too great, a common problem
5. We have to compromise by sacrificing detail at one end of the scale unless something is done to alter the high contrast
6. By moving down everything one zone, the foreground becomes nearly black (Zone I), but the cliff highlights becomes a satisfactory Zone VIII

Though it was difficult to take all the steps, it would be funny in make photo processing.  Basic / foundation is very important.

Here is my photo sharing for zone system practices.  May be it wasn't good  enough.

Use a pencil to draw the product like NDS

Take a Color photo

Use photoshop changed the color in BW, so you may see what kind of different between I draw and photo. I would be funny to understand what's my weakness in color sensitivity. If we well done in B&W zone system, color zone system would handle easily.

Enjoy in your photography!

[ 本帖最後由假書僮於 2007-12-30 07:29 PM 編輯 ]

1 評分次數