"Live camera to screen" refers to sending a live camera feed of the presenter to one or more screens, generally located above the stage, so that all those in the audience can see clearly. This is generally used in larger venues, and brings about its own challenges.
When organising camera to screen, a number of factors affect the camera operator's ability to record or capture the images they to, so these need to be discussed ahead of time.
The distance between the camera and the presenter influences whether or not the camera can be operated from a tripod or on-the-shoulder, and the amount of light available.
We generally record audio from the sound-desk rather than from an on-board microphone, and this can be done through either a cable (not practical for moving camera situations) or via wireless transmitter. Specialist lenses may be required if the focal distance is quite long, in order to get the size of image desired, as well as a camera riser to give height, in order to get the correct angle.
At the control end, is generally a vision mixer, audio mixer, and lighting mixer, all working as a team to combine all elements as a whole.