Birmingham New Street has 13 platforms and visibility isn’t the best in this station as it is so dark inside the station and you can’t really take photos. The two ends of the station are fine and you can see most of the trains but on cold days it isn’t very appealing to stand outside – but on hot days it is perfect. On cold days you just choose your platform and you just see whats on your chosen platform the only way you could get around this issue is if you had a camera that has a big optical zoom.
There are plenty of things to do and to eat and drink at the station outside the platforms in Grand Central and the Bull Ring. The tram stop is right outside the station if you go out via New Street.
I would recommend this station for trainspotting if you just agree it is impossible to see all the trains that arrive and depart from the station.