Why do you want to compress the density range of the original when printing and copying? How should it be compressed?

You wouldn't understand if I told you.

When the density range of the manuscript is too large, the sensitivity of the scanner and the electronic version to the part beyond the density range decreases, and the color separation layer becomes flat. According to practice, the density range of the manuscript is 0.3 ~ 2. 1, that is, the contrast is 1.8. The original density difference of color reversal film is controlled within 2.4. If the contrast of the original image is less than 2.5, reasonable compression will be achieved and the effect will be ideal. If the contrast of the manuscript is greater than 2.5, even if the gray-scale compression is carried out during copying, too many layers will be lost, and the merger will be serious and the effect will be poor.