HG/T 2620-1994 Method for determination of sensitivity and average slope of color motion picture films HG/T2620-1994 Standard download decompression password: www.bzxz.net

Chemical Industry Standard of the People's Republic of China
HG / T 2620 -- 94
Method for determination of the sensitivity and average slope of color motion picture films
Issued on April 13, 1994
Ministry of Chemical Industry of the People's Republic of China
Implemented on January 1, 1995
Chemical Industry Standard of the People's Republic of China
Method for determination of the sensitivity and average slope of color motion picture films
Subject content and scope of application
HG / T 2620 - 94
This standard specifies the method for obtaining the sensitivity and average slope of color film positive film and the test technical conditions. This standard is applicable to the determination of the sensitivity and average slope of color film positive film used for making color film copies by the base and positive method, and is also applicable to the determination of the sensitivity and average slope of color positive materials used to make slides. 2 Reference standards
G.B11500 Geometric conditions for photographic transmission density measurement GB11501 Spectral conditions for photographic density measurement GB/T15061 General rules for photosensitivity measurement of silver salt photosensitive materials Part 1 Exposure conditions for samples applicable to incandescent tungsten light and simulated daylight
3 TerminologybZxz.net
3.1 Sensitivity
Quantitative expression of the sensitivity of photosensitive materials to light radiation energy under specified exposure, processing and testing conditions. 3.2 Sensitivity balance
The ratio of the sensitivities of the red, green and blue photosensitive layers of the color photosensitive material. 3.3. Average slope
The tangent of the angle between the line connecting two specific points on the characteristic curve of the photosensitive material and the horizontal coordinate, divided into the upper average slope and the toe average slope
3.4 ​​Average slope balance
On the characteristic curve of the red, green and blue photosensitive layers of the color photosensitive material, the maximum and minimum values ​​of the three upper or toe average slopes.
4 Test method
4.1 Sample preparation
The sample should reach equilibrium at a temperature of 23±2℃ and a relative humidity of 50%±5% before sampling. 4.2 Exposure 4.2.1 The photosensitive instrument adopts a non-intermittent dimming type. 4.2.2 The light source should comply with the provisions of 3.3.4A light source of GB/T15061. During exposure, a filter that simulates the spectrum absorption of the color intermediate film mask (MASK) should be added between the light source and the light window, such as the Kodak 1700 combination filter approved by the Ministry of Chemical Industry of the People's Republic of China on April 13, 1994 and implemented on January 1, 1995. The spectral transmission distribution of the Kodak 1700 combination filter is shown in Table A.1.4.2.3 of Appendix A. The standard light source should comply with the provisions of 3.5 modulator of GR/T 15061. 4.2.4 Exposure time
To avoid the failure of the reciprocity law, the instantaneous exposure time should be selected between 1/10 and 1/100 s. 4.2.5 Exposure control
The exposure amount applied to the sample should be such that a complete characteristic curve can be obtained under the processing conditions specified in 4.3. The uncertainty of the amount of light used to determine the film sensitivity should not exceed 0.03 logarithmic units. 4.3. Processing
After exposure, the sample should be processed within 2 hours to avoid latent image decay. The sample should be processed according to the formula and process recommended by the film manufacturer; if the manufacturer does not recommend a formula and process, it should be processed according to the general processing specifications.
4.4 Density measurement
Measure the optical density of the washed sample. A photoelectric densitometer with red, green and blue color filters should be used. The geometric optical conditions of the densitometer should conform to the relevant provisions of GB11500 for diffuse transmission density. The spectral conditions should conform to the relevant provisions of GB11501 on standard A state density. The measured density is the A state diffuse transmission density. 4.5 Drawing of photosensitive characteristic curves
With density as the ordinate and the logarithm of daylight as the abscissa, draw three photosensitive characteristic curves for red, green and blue, respectively, as shown in Figure 1.
5 Measurement of sensitivity
5.1 Determination of the reference point of sensitivity
HG/ T 2620 94
Figure 1 Schematic diagram of the sensitivity characteristic curve of color motion picture positive film G
On the three sensitivity characteristic curves of red, green and blue, mark the density points whose density values ​​are equal to their respective minimum density (fog density film base density) plus 1.0: Mr, MgM (see Figure 1). These three points are the reference points for obtaining the sensitivity of the three photosensitive layers, and their corresponding instantaneous optical disks are H, Ha, H respectively.
5.2 Calculation of sensitivity
HG / T 2620 -94
The sensitivity of the three photosensitive layers of color film is calculated according to formula (1): S
Wherein: S—sensitivity;
Hm——the amount of warm light corresponding to the reference point of the whole light, unit: lux.5:10-
Specified constant
When H is taken as H., the sensitivity of the red layer can be obtained (S); when HM is taken as Ha, the sensitivity of the green layer can be obtained (Sc); when HM is taken as H, the sensitivity of the blue layer can be obtained (S)3.3 Calculation of sensitivity balance
Taking the sensitivity of the lowest layer as the base 1.0, calculate the other The ratio of the sensitivity of the two layers to the sensitivity of the lowest layer, and then write the ratio (Sk: S: Ss) in the order of red and blue, to express the sensitivity balance green
Measurement of the average slope
Take the reference point M of the sensitivity on the sensitivity characteristic curve of each tea as the center, and divide it into upper and lower sections for measurement. The calculation of the upper average slope
is shown in Figure 2. In the upper part of the characteristic curve, find the corresponding point S whose horizontal coordinate is 0.5 units higher than the corresponding exposure logarithm of the sensitivity reference point M. The slope of the straight line connecting M and S is the upper average slope, which is calculated according to formula (2): Gs
Where: Gs
Upper average slope;
-Dt ... Calculation:
-upper average slope balance
The maximum value of the upper average slope in the three photosensitive characteristic curves of red, green and blue; The minimum value of the upper average slope in the three photosensitive characteristic curves of red, green and blue. ! Toe average slope balance
HG/ T 2620 -—94
The difference between the maximum and minimum values ​​of the toe average slope in the three photosensitive characteristic curves of red, green and blue is the toe average slope balance, which is calculated according to formula: (5):
In the formula: G,
-toe average slope balance;
-the maximum value of the toe average slope in the three photosensitive characteristic curves of red, green and blue; the minimum value of the toe average slope in the three photosensitive characteristic curves of red, green and blue GTmle
Figure 2 Schematic diagram for obtaining the average slope
HG / T 2620 -—94
The difference between the maximum and minimum values ​​of the toe average slope in the three photosensitive characteristic curves of red, green and blue GTmle
Figure 2 Schematic diagram for obtaining the average slope
HG / T 2620 - 94
Appendix A
Spectral transmittance distribution of Kodak 1700 combination filter (supplement)
Additional notes:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China, and
This standard is under the jurisdiction of the First Film Factory of China Lucky Film Corporation. This standard was drafted by the China Film Science and Technology Research Institute, and China Film Equipment Corporation and the First Film Factory of China Lucky Film Corporation participated in the drafting.
The main drafters of this standard are Mou Xiufang, Ji Jiaqi, Yue Zi, and Tang Zhijian. People's Republic of China
Chemical Industry Standard
Method for determination of sensitivity and average slope of color film
HG/T 2620 94
Editor: Chemical Industry Standard Editorial Department
(Institute of Standardization, Ministry of Chemical Industry)
Postal code: 100011
Printing: Institute of Standardization, Ministry of Chemical Industry
Copyright: All rights reserved. Printing without prior notice
Bonus B80×12301/16 Number of printed sheets: 12000 First edition: December 1994 First printing: December 1994 Number of printed sheets: 1 — 500
Cost: RMB 2.90
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