• Camera fixed on tripod
• Its crucial to place the tripod on a surface, where there will be no vibrations
• Camera has to have a clear line sight to the scoreboard
• Use maximum zoom (even digital), but keep the whole scoreboard in the frame
• Use manual exposure, not auto exposure. Choose darker picture in order to have more contrast between digits and the scoreboard, therefore making digits more visible. Setting manual exposure makes sure that exposure will not change due to nearby LCD screens displaying ads. If available, apply ND filter
• Use manual focus
• Choose between 50/60hz to make sure that digits are not flickering depending on the refresh rate (Hz) of the display.

IP security camera that supports RTSP is a very cheap and flexible solution. For 150-200 EUR you can buy a camera with remote pan, tilt, zoom, focus, contrast control, which makes it possible to use PoE, attach camera to a distant position (for example to ceiling) and at any point of time adjust the video frame remotely. Keep in mind that RTSP protocol will introduce up to 400ms of input latency.