I applied smoothcam to a clip and I went to adjust the settings in the Viewer's Filter tab. I set all three camera motion smoothness settings to 1. I then played with the auto-scale in an effort to reduce the "actual scale" as much as possible. I has Auto Scale set to 0.55 and an "Actual Scale" of 109%. I read on some forum that one way to reduce the actual scale is to use the razor blade to cut out the odd extreme frame that goes really strange. I went through the clip and every time I saw the black edges I would use the razor to cut out the offending frames. So I replayed the new clip from the start and found more instances of these bad frames where you can see the edges. Does anyone know why this happens? Also, sometimes when I would find a bad frame with black edges, once I made the first cut with the razor, when I scanned over it frame-by-frame to to the end of the series of bad frames, it would appear as if the bad frames had disappeared without me actually deleting them from the timeline. Maybe these are related? Any help would be appreciated - I'd love to keep the Auto Scale setting as low as possible to retain as much of the original image as possible.
Tim

I fly RC helicopters with the Canon 5DMII and the Sony EX1. I use stabilizing software every day for all of my footage. That's my background.

So, when you "cut out the offending frame" and then smoothcam looks at it, it has a hard time adjusting to the change or sudden shifting of all the pixels. Your "offending frame" is Smoothcam's way of cropping and shifting all the pixels in the image in an attempt to smooth the clip. The only way to smooth a clip is by shifting all the pixels, causing black borders when adjustments are made.

Other tips:

Smoothcam and stabilizers in general work ok on smooth, slow jiggles and bobbles, but they have a hard time with fast motion bobbles, often times distorting the image.

Smoothcam, oddly enough, doesn't work as well as a cheaper program called I-Stabilize. I-Stabilize handles ProRes and Apple Intermediate codecs well, renders and analyzes clips WAY faster than Smoothcam, and overall is much easier to get good results with.

Be sure your footage is deinterlaced if you're not shooting progressive. Progressive footage is easier to stabilize.