Use the Dissolve Curves window in the Dissolve menu to edit the rate at which the dissolve changes. There are two curves: one represents the outgoing shot and the other represents the incoming shot. These curves are plotted on a graph that shows Time vs. Percent Visible. When curves are at the top of the window, the frames at that point in time are 100% visible. Curves near the bottom correspond to 0% visible frames.

By default, each curve progresses in a linear fashion from one corner of the window to the opposite corner.

To modify the dissolve curve:

1. In the Edit menu, click Dissolve to display the Dissolve menu.
2. Enable Interact In or Out to specify whether you are modifying the outgoing or incoming frames of the dissolve. You can also work on both curves simultaneously.

   
   

   (a) Interact In/Out buttons  (b) Adjusting the Bezier handle  

3. Click one of the keyframes and drag the Bezier handle to adjust the rate at which the dissolve takes place.

   You can change the start or end visibility to any value between 0-100%; however, you cannot adjust the time at which a dissolve starts or ends in the Dissolve Curves window. To do this, return to the Edit menu and use the Dissolve slider.