Quote Originally Posted by Photo Engineer View Post

But, don't use a blue filter. Since a plain raw emulsion is blue sensitive, no filter will give you much higher speed.

Best of luck.

That is assuming that I am using 3 emulsions. 1 each with no spectral dye;a green sensitive dye;and a red sensitive dye. That is a possibility. But if I use a single Pan emulsion, I nead 3 negs. one each made with red; green and blue filters. No filter will give me a full spectrum negative.