My projects are not very complicated, they are simply high resolution time lapses, this may effect what I'm about to ask. The manual states the following ways to scale a movie down:
Nest the composition (with smaller dimension) - 2nd best option
Resize the composition - highest qualtiy option
Crop the composition
Crop to region of interest
Render the composition at reduced resolution - worst quality option
1.) It does not say anything about changing the original composition setting's width/height value and then using the scale option within transform. Doing so sounds a lot to me like "resizing the composition" although the example the manual gives for "resizing the composition" is to resize the value in the output module and render at full resolution. For the best option are they specifically referring to the use of the output module? How would scaling down in the original composition compare to the other varieties, would it be similar to the nesting option?
2.) For many of my projects the dimensions don't scale down to 1920:1080 in whole numbers. In this case would it be best to nest the composition (or resize and scale like I described above) to an amount that would divide to my desired resolution in whole numbers and then resize the value in the output module? Or would it be fine to simply resize in output module assuming that's what they mean to achieve highest quality scale down.
You really can't beat the simplest method, which is to place the footage into a comp in its final dimensions, then scaling the footage to taste. AE does a great job of it.
If the footage happens to be in the same aspect ratio that you intend to deliver -- and you want to use the entire image -- it gets even easier. Under the Layer menu, navigate to the "fit the layer to the comp" command... I forget the exact wording. The keyboard shortcut is Cmd-Opt-f on a Mac, and I guess it would be Ctl-Alt-f on a Windows box.
Former Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA