Logo Printed Wine Box Color Correction Process, How To Calculate And Modify The Exposure Time?

Logo Printed Wine Box color correction process, how to calculate and modify the exposure time?

 

To calculate and modify the exposure time according to the sample, it is necessary to first know the change value of the three factors that cause the exposure time change in the color process (namely: the density of the color correction filter, the number of sheets and the density of the sample, etc.) in the exposure time, and then calculate the new exposure time according to these values.

 

(1) The effect of the change of color filter density on the exposure time Generally speaking, the effect of magenta and green color filters on the exposure amount is basically the same, and the exposure time needs to be increased or reduced by 10% for each increase or decrease of 10 densities. The yellow filter has little effect on the exposure amount, and the exposure time is only 10% difference when the difference is 40 densities. The following two tables are obtained for reference when calculating exposure time. Effect of density change of magenta and cyan filters on exposure time

 

(2) The effect of the change of the number of color filters on the exposure time is generally good at the light transmittance of the new color filter, and the exposure amount of each filter is 10% different. If the filter is old and the surface is brushed, the light transmittance will decrease, and each filter will have a difference of 15% or more exposure time. The influence of color filter number change on exposure time

 

(3) The influence of the density of the sample on the exposure time If the exposure time is too much or too little, the exposure time should be modified according to the amount (percentage) of the density is too much or too little, according to the data in the table. Sample density size (dark light) to modify the exposure time, the following two examples to illustrate the calculation method when modifying sample exposure.

 

Example 1: The original sample filter combination is 604000.

Exposure time: 10 seconds

Number of color filters: 2

After the sample is judged to be magenta, it is estimated that 20 density magenta filters should be added. The sample density is low, and it is estimated that the exposure will be increased by 10%.

 

Therefore, the modified filter combination is 606000

Look up the table, increase the density of 20 magenta should be ×1.2

The number of filters has not changed

According to the table, the density should be less than 10% ×1.1

Therefore, the exposure time is changed to: 10(seconds)×1.2×1.1=13.2 (seconds).

 

Example 2: The original sample filter combination is 403000

Exposure time: 15 seconds

Number of color filters: 2

After the sample is judged: the color is yellowish 30 density, green 15 density, the sample light is lighter 20%.

 

Therefore, the modified combination of the filter is: 403000+300015703015-151515551500

The revised changes are:

Yellow filter increases density by 15 ×1.05

Magenta filter reduces density by 15 ×0.85

Add two pieces of filter ×1.2

Then the exposure time should be modified:

15 (s) ×1.05×0.85×1.2=16 (s)