Acting for film is extremely rewarding, but it is not for everybody. Even actors who may have performed onstage for ten years might find they don't like film acting and all that is required of it.
Actors who have done a lot of film or video work tend to be very enthusiastic and supportive as long as they are fed well and have a very clear expectation of what is required of them.
If you are working with actors who do not have a lot of experience in front of the camera, the best thing you can do is communicate very clearly, before the shoot, what it is going to be like.
For instance, believe it or not, people who have never been on a film shoot before have no idea how long it can take to get the lighting right, even if you have an experienced gaffer. They also don't understand why the sound guy will suddenly make the entire shoot stand still while he figures out a hum that they can't hear with their naked ears.
Experienced actors get used to all of this. But there are still adjustments as one progresses up through the levels of filmmaking and acting.
For instance, an actor may have a lot experience on camera, but only in commercials and industrials for which they only had half-day shoots. So, he or she might not realize what an 8-10 hour shoot is like.
Another example: An actor may have acted in 8 or 9 short films and had day parts in some features, but then have no idea what it is like to be cast as the lead or strong supporting character in an indie feature. Suddenly, this actor has to get used to the rigor of shooting five eight hour days in row, with scenes out of order from the script, and one of them a night shoot with only twelve hours off until the next call time.
As an actor, I know there seems to always be a learning curve at each new level I've progressed to.
