It may be against the company's Ts and Cs of carriage (doubt that very much) and I'd want to see that in writing before I put my camera away
By flying you have already accepted the Ts and Cs. If you bothered to read them, you will find cabin crew can tell you to do pretty much anything and if you argue you get put in the restraints, a diversion, and you pay the costs...
From BA T&C, but almost all airlines are basically the same (emphasis in red added)...
7a) Our right to refuse to carry you
We may decide to refuse to carry
you or
your baggage if one or more of the following has happened or
we reasonably believe may happen.
...
7a7) If
you have not obeyed the instructions of
our ground staff or a member of the crew of the aircraft relating to safety or security.
...
11b) Diversion costs caused by unacceptable behaviour
If, as a result of your behaviour,
we divert the aircraft to an unscheduled place of destination and make
you leave the aircraft,
you must pay us the reasonable and proper costs of the diversion.
11c) Using electronic devices on board the aircraft
For safety reasons,
we may decide not to allow
you to use electronic devices when
you are on board the aircraft, including:
- mobile phones
- laptop computers
- personal recorders
- personal radios
- MP3, cassette and CD players
- electronic games or
- transmitting devices (for example, radio-controlled toys and walkie-talkies).
You must not use these items when we have told you that they are not allowed.
We will allow
you to use hearing aids and heart pacemakers.
So basically, the message is listen to your cabin crew, do as your told, and if you think they are going above and beyond ask to speak to the Cabin Manager, then do as s/he says.
The other general piece of advice is always read the contract before accepting it.