Stabiliser Expand

[tc_leeds]

How does the "Expand" feature in the Stabilisation section work?

TC

[jkb]

As I understand it, when you stabilise, you could end up with black edges/corners as it may crop the image to be able to align each of the video frames.

By Expanding, you effectively zoom into the image a bit to remove these.

Jill

[tc_leeds]

Hi Jill, That is what I understand it to mean but always thought that the zoom required to accommodate the stabilisation was an integral part of the choice of the option selected.

Tony

[Igor]

Hi Tony,

Yes, the stabilisation mode automatically decides how much zoom is needed to effectively stabilise a video frame (even if you set the Expand to "0").

However sometimes (rarely) small black bars may appear on the edges in case of strong shaking in a frame. In this case, the Expand option will help to correct a frame.

Also if even the "Strong" stabilisation mode doesn't help to stabilise a video frame (or if you want a perfect stabilisation!), the Expand option gives the stabilisation algorithm more screen space for more effective stabilisation. Try values between 5-10 for the Expand option.

Consider another mode - Camera Lock, if the movement in the frame is small (shooting handheld, but the operator tries not to move a camera, not to turn a camera). In this case, stabilisation will be ideal, as if you were shooting from a fixed tripod.

I've checked many video files from different sources, from different cameras. Normal or Strong modes do a good job for 95% of shaky video files without using the Expand option.

In the following promo video, I've used Strong mode for a stabilisation of the 1st video (Expand = "0", by default) and Camera Lock mode for the second video: 
https://www.youtube.com/watch?v=oWu-IlXTDvE

P.S. Jill, thanks for your comment!