
Originally Posted by
Janke
To avoid the "pumping" of brightness between scenes, light the paper with some stray light, preferably an "enlarger" lamp. (A lamp used in old-type photo enlargers, it has a color temperature close to 3200K, as the projector lamp.) Or, you can use an ordinary household 60W bulb, reflected from a light blueish paper, to get the correct color of stray light. No fluorescents!
This will reduce the contrast, improve the blacks, and minimize pumping. If your stray light is too strong, you can crush the blacks a bit in edit.