ROS2: Understand TF tree: camera_optical VS camera_optical/static

[AmitNativ1984]

Discussed in #4352

^{Originally posted by AmitNativ1984 February 15, 2022}
Problem:
I have created a stereo camera by setting up left and right cameras in the settings file, from which I want to calculate depth.
I use ros2 tf to find the baseline between the left and right cameras.
The camera_info->header.frame_id for left and right cameras, is left_stereo_camera_optical and right_stereo_camera_optical respectively.
However, looking in rviz, I see the relative distance between the optical frames is incorrect. Instead, the frame called left_stereo_camera_optical/static and right_stereo_camera_optical/static are positioned correctly.
This is a problem because camera_info reports the optical frame, rather than optical/static frame, and these are the frames used in tf lookupTransform.

Also, the TF tree looks strange. I would expect the optical frame to be the child frame of the odom_local_ned.

I would appreciate some help to understand what's going on.
Thanks!