CX HK was referring to HKG and here I've left permitted liquids in my closed carry-on for a long time already. Just some newbies want to take a closer look since i've packed it to the max when going on long-haul with carry-on only. I take it out at all other airports though to expedite security check.

Haven't been back to SIN after getting a tablet. I'm shocked to read from kesler.go that they not only want the iPad out for security check, but as well out of the sleeve... A good example for just simply transferring rules intended for something else without knowing whether it makes any sense Taking the laptops out of the bag make it easier and quicker to see their printed circuit boards separated from chaotic cables and other items like dense batteries, which may look in combination like the "improvised" part of an IED.

But back to the topic: Agree with other posters that it depends on the crew and that it's usually OK as long as you don't use it in front of the crew. As well agreeing with FriendlySkies that no one bothers when using a camera in the privacy of the 744's 1A suite during take-off and landing or even a small bike-computer's GPS to record the flight-path... However, when flying in Y (which is unfortunately the majority), some FAs even ask me to even unplug my noise-isolating (unlike noise-canceling NO battery involved) earphones plugged via converter to the IFE - since they're in-ear, they have even smaller electro-magnets than the CX headsets...

I know as well some who forgot switching off their phones during an entire long-haul flight. Mobile phones scale their output from a few mili-Watts to 2 Watts. The maximum output is usually generated when trying to get a connection, which drains as well the battery much quicker than when having good connection all the time. Those ppl were able to tell me the story because their plane obviously didn't crash... I don't see any risks with cameras though - only when using the flash it might generate an electric pulse, but much weaker than any mobile phone. There is no conclusive evidence, so most are just being better safe than sorry.