Well I think I have mastered the cropping filter for my needs except for one problem which is very strange.
I setup a crop filter in the middle of a 16x9 clip and set the height and width percentages to 4x3 ratio (think I used 60% x 45%). The resulting clip is just what I want.
Now for the fun .. I previewed the crop filter in the little preview window. As the clip is playing deeper into it's timeline, the height and width percentage numbers begin to change and get larger. by the end of the clip they are close to 100% in both width and height.
I tried the stationary check box and a few other things, but it does not stop the numbers from changing.
So, is there a way to keep the clip size constant for the duration of the clip? These changing height and width percentages mess up my crop of the clip!
