I am running ROS Noetic inside a docker contianer (using the one provided by sterelabs) and I am seeing frame drops. The video feed of the left/image_rect_color topic hits ~ 20 Hz but is unstable varying quite a bit. When I use rostopic hz I am seeing max delta_t of 0.5 s with average fps of 20 Hz.
I have another USB camera runnung using cv_camera ROS node and I get perfectly smooth 15 fps with that.
When I use the camera without the ROS wrapper I get a good feed (ZED_Explorer)
The final frequency depends on the configuration of the Wrapper.
The resolution of the ZED image is high and this can affect the final performance of ROS.
I recommend you tune the configuration to obtain the required performance.
So it turns out the issue was related to my docker container running jetpack 5.1.0 and the ZED BOx running 5.1.1. Once I updated my container to the correct version, the performance is much better