Re: Film Dissolve vs. Video Dissolve

Sure...of course old-fashioned film dissolves were (are?) done using an optical printer in which both a A-roll negative shot and the B-roll negative shot are combined onto a 3rd negative roll of film using the opening and closing of the optical printer's projector aperture.

According to the ENCYCLOPEDIA OF VISUAL EFFECTS cookbook it can be mimicked in Shake by using a Brightness node running from your A-roll FileIn attached to the first input of a Screen node and a second Brightness node running from your B-roll to the second input of the Screen node to screen comp 'em together. Basically you mimic the optical printer aperture by starting the A-roll brightness node off at 100 percent, then reducing it to 0 and doing the reverse on the B-roll Brightness node (fade from 0 to 100 percent). The Screen node basically keeps the final ouput from being clipped. They also show a nifty trick of automating the second Brightness node with the linking expression "1-Brightness1.value"

Definitely pick up a copy of the book (mine's already dog-eared; it's a perfect resource for relative Shake newbies like myself).