Toe (AB): This part of the slope of the curve is very small, almost parallel with the abscissa. Racing Flags Black after exposure density and exposure value does not exist a positive relationship. Exposure increase is much more sensitive to the value of the density values increased very little. This part of the curve, also known as the underexposed part. Part, without the exposure of photosensitive material after imaging processing will produce density, as shown in point A shown. Custom Wind Flags
This density is known as the fog density. Racing Flags
Linear part (BC section): exposure in this part that is proportional to the value and density value, so the characteristic curve as a straight line. Straight line portion, also known as the exposure correct part. This part can correct demonstration of the different brightness of the scenery. Shades of the image entirely in proportion to display. The straight portion of the main part of curve, must take full advantage of it.Racing Flags
Shoulder (CD section): After exposure to a certain value, the exposure values continue to increase, while the density increases less.
This part is also known as the overexposed part. Swooper Flags Wholesale Prices
Reverse part of the (CD section): With the increase of exposure, the density values not only do not rise, but tends to go down, so that the characteristic curves bent downwards, Racing Flags this part of the curve known as the reverse part is a special sensitometric phenomenon.
With increasing exposure, the maximum density called the maximum density in the Dmax. The maximum density reflect the top of the Bei (Figure D points).
Photosensitive materials of different film types have different requirements on the Dmax. If you can not reach the technical indicators, will directly affect the quality of the image.
(3) photographic light source. The camera ideal light source is sunlight. Plate camera in the room, therefore, the choice of spectral and color of the light source must be close to the sunlight.
① the spectrum of light. The light source of light of various wavelengths of light intensity is different. Wavelength as the abscissa, the relative energy of various wavelengths of the size of the vertical axis, you can draw the energy of light radiation wavelength distribution curve. Figure 2-95.
Figure 2-95 xenon light energy distribution Cheap Swooper Flags
The light spectrum is a very important characteristic of the light source a variety of features. Photomechanical light in the wavelength range of 400 ~ 700nm, and its spectrum is continuous spectrum should be close to daylight.
② the color of the light source. There are two aspects of the meaning of the color of the light source, Racing Flags a direct observation of the light source of the human eye to see the color perception, which is known as the light source's color table to represent the color temperature; the other is the light source in the object objective results, pass color coefficient.
The color temperature of light sources in general is the absolute temperature of the blackbody radiation effect as a standard of absolute black body heated to a temperature of color and light color is basically the same, absolute black body when the absolute temperature, the color temperature of light source. Absolute temperature is equal to the temperature plus 273 degrees Celsius. Or 0 ° C + 273 K,