As a filmmaker, writer, actor, or casting director, you've got an affinity for dramatic scenes; scenes that steal the show; scenes that show off your actor's thespian chops; scenes that you imagine as the "Oscar Clip" you'd use should you be nominated.
But often times, our affinity for the dramatic in the casting room isn't always the best choice when assessing its' effect on the overall arc of the story that's being told in your production.
Yes, it's true a short film or feature is a collection of scenes- but all of these scenes must tell a linear, coherent and emotionally believable story. When actors get excited, or sad, or upset, these emotions must be part of some larger scheme, and must logically escalate into a plausible emotional climax, rather than simply be inserted in the middle of two seemingly normal and non-eventful scenes.
So filmmakers- the next time you're in a casting facility, casting your next masterpiece, be sure to select actors that act out your material realistically, and treat the scene their auditioning for as a natural progression from the scenes that came before it. And actors- the next time you're in a casting room and don't know how dramatic to make a scene, be sure to ask the director more about your character and his or her circumstances so that you can deliver a realistic performance that can ultimately add authenticity to the entire production.