In article , Paul
wrote:

But, why have a 6 minute limit?

tariffs.

What if for example you are shooting an
interview, a speech, a music/theatrical scene, etc. or even a 'special' home
movie? Why the restriction? Surely it's not to allow the sensor to cool
down if you can start recording again immediately?

the sensor does not heat up. someone on dpreview used one of those
infrared temperature measuring devices after using live view for over
an hour on a d3 and found no significant change, nor any effect in the
images produced. furthermore, if it really was due to heat, the camera
would block the user from taking a second 5 minute movie immediately
after the first, and it would also limit live view to no more than 5
minute intervals.

the real reason is that a 'video camera' is taxed differently, so by
limiting it, it doesn't qualify as a 'video camera.'