مرشحات تستخدم للأفلام الملونة وكذلك للأفلام الأبيض واسود .. كتاب التصوير علم وفن

Third, filters are used for color films as well as for black and white films

These filters can be used with all types of films as they perform their function without disturbing the color balance.

(a) Ultraviolet filter (U.V.Filter): This filter has no color, has no filter coefficient, and does not require exposure adjustment. All that this filter does is prevent most of the ultraviolet rays from entering. We notice that distant scenes appear blue in color images, and in black and white images they appear with a white hazy tinge. This is what is called the air perspective as a result of the scattering of ultraviolet rays in the atmosphere due to the effect of dust and moisture, or to increase the reflection of rays in places that have sand, water or ice. We can get rid of part of this aerial perspective by using this filter. Many photographers constantly put this filter on each

lens to protect it

(b) Haze filter: It is similar to the previous filter, but it is slightly stronger and is preferable to be used with color films. Its color tends to the color of straw, that is, it tends to be yellow and does not need to be overexposed.

(c) Polarizer: Light waves vibrate in all directions, and this filter does not allow these waves to pass except those that vibrate in a certain direction or level.

This filter is used for:
- Make the blue sky darker, especially in color films, as this is the only way to do so. As for black and white films, this can be done by other means, such as a yellow or orange filter, etc. To make the sky completely black in black-and-white movies, the polar filter can be used in combination with a standing red filter.

the sun

list in this direction

The base of the thumb and forefinger of the polar candidate is the knowledge of the sky that will become the list

Prevent reflections from non-metallic objects such as glass, water and polished objects. The reason for this is that the light, when it is reflected from polished non-metallic objects, is polarized, meaning that all its waves become oscillating in one plane. If we put a polar filter in the way of these reflections, it is possible to control them either by allowing their passage, reducing them, or preventing them from passing by a large percentage.
It is noted that the filter coefficient for this filter is variable according to its position in front of the lens, so we adjust its position first in front of the lens until it gives the desired effect, then we measure the exposure through the built-in exposure meter in the camera, which automatically takes it into account. But if the camera does not have an exposure meter, then the filter is removed from the camera (there is a mark on the frame) of the filter and placed in the same position in front of a separate exposure meter and the reading is noted and then put back on the camera carefully so as not to change its position. Usually the filter coefficient ranges between 2 and 8 any aperture to three Increase slots with note placement

We depict (D) a neutral density filter: these filters are gray in color and therefore absorb all colors in one proportion and do not change the color balance. There are several densities of this filter and their purpose is to reduce the amount of light falling on the film. For example, if the camera has a fast film and we want to open a wide pupil or a slow shutter speed for some purpose, and the amount of light does not allow us to do so. In this case, there is no solution but density filters. These filters are available in several densities, the best of which is a type with a density of 0.6, which requires an increase in the exposure of two holes, and a second with a density of 9. And it needs to increase the exposure of three slots. Using the first type is a film whose speed is 400 ISO, and 40 ISO becomes as if we are dealing with a film whose speed is 100 ISO, and so on.