وحدة قياس شدة الاضاءة. الدرس الأول: التعريف بواحدات قياس الفيض الضوئي وشدة الضوء والتحويل بينها

A strong key light and a weak fill light means a more contrasty image and vice-versa 4:1 ratio: Higher contrast resulting in a low key image
RASHID, , Page 539-540, Part 23 Thus light becomes more directional, focused thus turning into hard light

It is therefore crucial to get yourself equipped with the techniques of lighting, the nature of light and its effective uses.

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وحدة قياس شدة الضوء
A light ratio of 3:1 is desirable for
استضاءة
As the distance is doubled, the light spreads farther and a larger area is required to absorb the same quantity of light
جهاز قياس شدة الإضاءة
Artificial light is also used in fashion and glamor photography where it has to be balanced with the naturally available light
A proper balance can clearly bring out the contours and features of the subject while reducing undesirable shadows RASHID, , Page 223, Part 13
Similarly, different light ratios can be applied to obtain different results in an image The light rays in orange emanate from the source and fall on the card

Henry Semat,Robert Katz 1958 , , america: University of Nebraska - Lincoln, Page 673.

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وحدة قياس شدة التيار
Boylestad, , Page 131, Part 5
شدة الاضاءة ووحدة قياسها
Lighting is a unification of both art and science
وحدة قياس شدة التيار
Lighting Ratio A lighting ratio is simply the ratio or a balance between the intensity of two different lights
A combination of a strong key light and a weaker fill light allows more shadows thereby enhancing the contours and the contrast in the portrait The correct lighting setup can help you get astonishing results and a poor setup can totally ruin the shot
The Inverse Square Law comes in handy when adjusting the distance between the light and the subject In order to control these, a soft-light source is employed as fill-light

1:1 ratio: The key light and fill light of same intensity result in even lighting, thus producing soft high key image.

استضاءة
The photographer takes the reading of light intensity from each light source and thereafter adjust the intensity of light for each source to effectively put lighting ratios to action
وحدة قياس شدة الضوء
In a situation where the key light is absent and only a fill light is used, the portraits tend to appear flat
وحدة قياس شدة التيار
Boylestad, , Page 103, Part 4