stabilizing without zooming

fp615 wrote on 2/27/2012, 5:36 PM

I will try to explain...
I just received a mail where the editor says that the camera that shot all the details during a music concert was badly setup and the images are not good. He asks for the images I shot for entertaining myself.

I shot with a gh-1 and a full manual lens, a 50mm f1.7 to have better light but I shoot handheld at 1/50! So the images are a bit.... shaky...

Since the final video will be on dvd and the images were shot in full-hd, I was looking for a way to have the images stabilized but no zoom applied, since the video will be cropped on the timeline later...

Any help is welcome.

Thanks

Comments

Serena wrote on 2/27/2012, 5:49 PM

Any stabilization process can only stabilize data that is within a common frame, and of course that frame is smaller than the camera frame. The worse the shake the smaller the stable frame relative to the camera frame. Deshaker can fill the edges by interpolating data from adjacent frames, which can work well with a fairly constant background scene. It can't do this well when the surround has a lot of action. I can't comment on Mercalli.
Of course the best results are achieved using high shutter speeds (much shorter than 1/50).
Quite possibly your client might prefer to do the stabilization, if your footage is usable.

amendegw wrote on 2/27/2012, 6:23 PM

The nature of stabilization requires that the image be zoomed. The final image can display as minimally zoomed depending upon how the borders are filled. As Serena mentions, Deshaker employs a clever method of filling the borders by looking at adjacent frames. It's very good, but not perfect because occasionally movement near the edge of the frame creates some weird effects.

Mercalli is even worse. It either zooms the image or creates a blurred image in the borders (looks really crappy, imho). However, if you have the right footage (no pans or zooms and little motion in the border area) you manually fake out the stabilizer in Vegas. When Mercalli stabilizes, the first frame of the stabilized footage is full frame (i.e. no borders). One can capture an image of this first frame and mask out all but the borders - thus building the border in Vegas. Several months ago, I put together the following demo of Mercalli, zooming & border filling.

...Jerry

Laurence wrote on 2/27/2012, 7:29 PM

I've stabilized without zooming using the Deshaker script, but that only works with a static unchanging background. A sea of live moving concert goers wouldn't work.

tim-evans wrote on 2/27/2012, 7:55 PM

I use deshaker without filling the borders and then I use a mask to cover the frame movement. Works real well for me.

Chienworks wrote on 2/27/2012, 8:44 PM

I can think of two things to contradict your premisis.

1 - if the shake is from shooting at 1/50, then it's likely the images themselves are blurred and there is no deshaking process that can fix it.

2 - Don't worry about whether it zooms or not. When rendering the output to SD there will be ample resolution available to crop as desired.

fp615 wrote on 2/28/2012, 1:50 AM

Thank you everybody for your answers.

The project is not a paid work, nobody gets money. It was a concert of friends, hobbist musicians, that once-in-a-lifetime rented a bit theater to play in front of a public...

As I said my camera was not supposed to be used so I shooted trying to learn how the lens reacted in various situations. Fortunately I didn't zoom (it was a prime lens :-) ) and didn't pan except to frame a new shot. Fortunately I stopped recording just a few times otherwise syncing could be very difficult.

The only problem are that little shaky footage that may be very visible when edited with other 3 cameras on tripod... So I wanted to stabilize them...

As far as I understand, deshaker is the way to go, with no zoom and with automatic border reconstruction... Should set it up asap on my workstation.

Thanks again
Francesco

riredale wrote on 2/28/2012, 5:09 PM

I suspect unless the footage is really crappy then no one will object to a bit of shaking. Just look at TV shows like "Law and Order" where camera shake is exaggerated to make the action appear live.

As for DeShaker, I love it. Lots of adjustments and flexibility possible. I never zoom in (causes loss of sharpness) but instead rely on a modest amount of steadying, edge filling (with before/after frames) and then a 4% mask to cover any remaining faults. The result is, to me, very satisfactory.