Liam Hall
Veteran
was told point blank that cameras NEVER go in the over heads..
Technically true, if it's not in a case it has to under the seat in front. If it doesn't fit, well you're screwed. Ultimately, it's up to the cabin crew to determine what you can and can't do as they are responsible for onboard safety. No point arguing, just have a back-up plan if you can, and if you can't, be prepared to take the pain when it comes your way.
I stick my FS7 in a roller bag, which while it's a legal size it's overweight for most airlines. I've been stopped at the gate many times, but always been able to blag it. My luck will run out soon enough...