Here are a couple of images to show the differences I am seeing between reaper's default settings and psycho's "widescreen" settings.
psycho's recommended settings:http://members.cox.net/markbooth/PsychoSettings.jpg
As you can see, the dotted white lines on psycho's settings have a much wider aspect. But when I attempt to animate with those settings, the window that opens for the frame rendering is EXACTLY the same size as with repear's settings. Granted, I only let it go for a few frames before stopping it but I don't think the window will magically get wider at some point.
Also, if you look at the image for reaper's settings, the innermost white dash rectangle is, apparently, the area that will be framed. With psycho's settings, the innermost rectangle is cropped too tightly while the second largest rectangle seems to exactly match the image size of the still (1280x720 jpg) that repear provided. Which white dash rectangle gets used? Or, do both (all) of them get used? And, more importantly, why does blender open up a 1.5 aspect window for psycho's settings too?
To experiment a bit, I did try setting the size to 1280x720 and setting the x and y both to 1. That resulted in white dash lines exactly matching the framing that psycho's settings displayed. And, when I click ANIM, the frame window that opens appears to be 16:9. But, at that size, it wasn't exactly hauling butt to build each frame.
If these things only took a couple of hours to render, I'd experiment away with glee. But given the extensive rendering time, I'd sure like to better understand what the final output might look like before I get started.
Again, any and all help is appreciated. I think it will be interesting to see just how fast I can get it done on my PowerMac. I've got a dual processor G5 running at 2.7GHz. I sure hope blender takes advantage of both processors.