Let’s say I am shooting a 23.98 35mbps project with the F330. I am not shooting any fast motion and most of the shots are interview talking head shots. Is there any need to use the shutter? Can someone give me a quick explanation or direct me to documentation as to when it is necessary other that dealing with fast motion. I did have to use shutter when shooting NTSC in Europe last year to eliminate ambient light flicker. Also, I have used it when shooting computer screens. My question is more in the direction of Documentary style production where there is almost no fast motion. Do I need shutter then? I have been shooting for many years and have used it for instance when capturing footage of a helicopter and I wanted to get that cool look with the blades. However, I have not noticed the need to engage shutter on basic "talking head type programs", am I wrong in that assumption?
If you'd search the archive here and at the Varicam site you'll find a lot of discussion about this topic, but the short answer is that yes, you should use shutter on at 180 degrees when shooting 24 or 30 fps; otherwise the shutter speed of 1/24th or 1/30th of a second creates more than the expected/usual motion blur.
In NTSC, even though you're shooting 30 frames per second, the interlace nature of it is making 60 fields per second, resulting in a 1/60th of a second shutter speed. This is what has established a "normal" and expected motion effect. By invoking a half shutter at 30fps, you are merely recreating what you'd consider normal. Now of course there are occasions, especially in low light where turning the shutter off would be helpful, and at that time it is certainly acceptable to do so, but remember to restore the shutter as soon as the light level allows.
The same holds true with slo mo effects.
In addition, the shutter is useful as you pointed out for special motion effects (helicopter blades, golf swings), computer screens (variable speed mode) and for eliminating flicker in 50 hz countries when shooting US speeds.
Don't take my word for it; shoot tests of motion at shutter on and shutter off and I'm sure you'll see what I'm talking about.
Set your shutter to 1/48. I think the other responder is right and with shutter OFF it matches the frame rate which is too slow. BUT...... if you read the SONY Shooting Tips #2 (the head and shoulders of the girl) Sony says to set the shutter OFF. I don't know why Sony says this.
Suffice it to say that Sony knows very little about the real use of their products. In the early days of video the engineers would always say to use more light, even though to do so ruined the effect or was counter to the creative intent.