Filming inside the parks (But not on the rides!)

The general rule is that photographs and videos may be taken in any unrestricted areas provided they are for personal use. However, you usually may not use external equipment (lenses, lights, tripods, selfie sticks, etc.) and should avoid disrupting other guests. Cameras may not be used on most thrill rides, and depending on the park's loose article policy you may be kicked out of line if you arrive at the loading station with objects that cannot fit securely in your pockets. Each park has their own policies and I am not particularly familiar with Universal's, but my guess is that you will not be able to take a camera beyond the metal detectors but may use it in the queue before that point (though my impression is that they are right at the queue entrance). If in doubt, contact the specific park for more information.

For Dragon Challenge, I believe you can walk to the metal detectors (past the Weasly Car and the Interlocking Corkscrews) with a camera. When you get to the metal detectors you can go back to the lockers.

There should be more home grown Disneyland movies. The bizarre guerrilla filmed movie never released to the public. Couldn't it somehow get leaked?

@Aron
Well I could make one...

I was just at Universal Orlando this past September 2015 and as soon as you hit the metal detector they checked. I had my camera (small), cell phone and some change in secured pockets but it all had to be put in the lockers. They do not want to take any chance (or change...sorry for the pun)of something accidentally coming out and hitting someone else. Let me know if anyone else experienced the same.

I remember last year I was there with a friend and she had a small stocking hat on to keep her head warm and they would not allow that. So she took it off and stuffed it inside her jacket and that was not allowed. It had to go in the locker.

But they do allow you to wear prescription glasses which could also fall off your face. Go figure.

Their house ..... their rules.

They told me to tuck my hat on the Rip Rockit. On Dragon Challenge one time they told me to put my U-Express lanyard in a locker even though it was my second time in a row riding. There are no real set rules. For perscription glasses, I've had seat checkers ask me if I was good with them on.