How to film backwards (maintain Yaw throughout mission)

To make sure I avoid the propellers in my video I am trying to set up a mission in Tower to have my 3DR Solo always point the camera backwards, i.e. set Yaw to 180 relative degrees for the entire mission. I’m trying to follow an undulating river, so an ROI won’t work for this. A couple of questions:

  1. What exactly does the “Relative” checkbox mean when you set the Yaw as a waypoint? I assumed it would mean “relative to the heading of the vehicle”, but I’m getting results that make me question this.
  2. When I set the Yaw, it only seems so apply up until the directly following waypoint, and then it resets the Yaw to the direction of travel. Is there a way to apply a Yaw-setting for an entire mission?

What is the closest thing to a manual for the Tower app anyone has found? Personally I am writing down all the lessons I’ve learned about how the app works from trial and error. Lacking an app manual, has anyone started gathering such notes from users to compile into a web page or similar?

Many thanks,
Andreas

Relative to original heading.
Absolute to magnetic north.

Means if the original heading is 85 degrees from north, the 180 will be added to the 85 for a heading of 265 relative to the original heading (where it is pointed).

Wherever north is to the river, the craft will be pointing due south with absolute selected.

Thank you.

Is there any different trick to do what I want, i.e. always point the camera straight backwards, regardless of vehicle heading?

I don’t own a Solo but if the gimbal is controlled via servo channels (as opposed to MAVlink or other serial), you could try DO_SET_SERVO…

Oh, so that what the “servo” value is for. =) I was trying to figure that out the other day. I’ll look into that and see if that gets me anywhere.

Thanks!

I coincidentally posted a similar (but not identical question) about the same time as this one: Region of disinterest?, although that is more about vehicle orientation than camera gimble orientation. I am curious if anyone has thoughts on that.

Well, the servo was a dead end for my purposes. The Solo gimbal won’t rotate 180 degrees.

To keep the propellers out of the video I guess it’s down to post production and cropping.