Study of Compared Color Temperature of Color Correction Filter from Luminaries for Motion Pictures

Abstract

The research is to study a light filter adjusting the color temperature of comparative light which is blue light frequency or (Color Temperature Blue: CTB) of number 201 Full CTB, 202 Half CTB, and 203 Quarter CTB by using with Fresnel Lens Lamp from 1000 W Tungsten–Halogen (T-H). Then, the measured value was compared with the calculated value from McCamy formula. The result found that, in the case of non-filter, the CT of T-H Light was 3060K of the measured value and 3067K of the calculated value. To change the CT, in the case of altering the number 201 filter which could change the CT from 3200K to 5700K, it could be measured the CT of the light from 3060K to 5258K with 7.754 % of the deviation, and the calculated value of the CT of the light changed from 3067K to 5259K. In the case of altering the number 202 filter to change the CT from 3200K to 4300K, the measured value changed from 3060K to 3910K with 9.069 % of the deviation, based on the calculation of 3067K to 3916K. In the case of 203 CT-change filter, the value was measured from 3060K to 3430K and its deviation was 4.722 % from the calculation of 3067K to 3439K. The causes of CT value of the deviation light in this research were in the measuring step, and the calculation. For the measuring step, the filters from various production companies contained different properties to change the CT, and the measuring instrument were not held steadily while studying. For the calculation, the CIE-1931 was needed for the basis of the measuring steps from moving the measuring instrument while measuring the value resulted in the deviation in the calculation step. Consequently, the research selected the properties of the Color Correction Filter of Blue Light Frequency or CT Blue: CTB which could bring the result to use an option of other light filters for measuring CT value of the color light frequency.