# Change camera zoom in real time

Hello.

I am trying to simulate a PTZ camera in Gazebo using this package and i was able to change pan and tilt in real time by using a position controller.

However, I have no clue about how to do the same with the focal length in order to emulate the zoom of the real camera. I was thinking about changing the fov parameter in real time, but it does not show when i run rosparam list, and I do not believe it would make any change in the simulation model right away.

Does anyone have any idea about how to approach this? Or if it is even possible in gazebo?

By the way, i am using ROS Indigo and Gazebo 2.2