Spot the mistake ...

[SmartWombat]

Ah, no, not the colour cast from the sodium lights, the other one.

When you're photographing TV images, it helps to understand how TV works.
Here in the UK we use the PAL standard, 25 frames per second made up of 50 interlaced fields per second.
So if you shoot at 1/50 second the screen will be about 1/2 brightness because you'll only capture the odd or even lines of the picture. If you shoot at 1/25 second then you will get both the odd end even lines.

But if you shoot at 1/60 second then there will be a dark band because it's faster than the refresh rate of the image.


OK, if you live in America that's all back to front.
You use the NTSC standard with uses 30 frames and 60 fields per second, not 25/50.
So you need to use 1/30 or 1/60 for proper exposure.

If I forget what country I'm in and user 1/50 in the USA then I get bright lines on the screen instead of a properly exposed image.