I remember back in 1978 when the then fairly new 3.9m Anglo Australian Telescope recorded faint pulses of light from the Vela pulsar, PSR 0833-45 which at the time made it the faintest star ever observed at mag 25.2.
Now some 33 years later it can just about be done with a 16" - 20" scope and an off the shelf CCD camera, all be they pretty good ones
The other thing to note here though is that our AAT was then the third largest and perhaps the best telescope in the world at the time and deffinitely a world leader.
Top effort boys, sure beats having to get hold of a 4m telescope and a fair bit less expense
Mike