Optimum exposure for home studio?
 

I have built a home studio to do some instructional videos (a person behind a desk demonstrating with hands how to do a task) and was wondering what is the optimum shutter speed and aperture I should try to obtain? So far I have 4 - 500w (2 x 250w bulbs) lights on stands with white umbrellas. I use 2 to light the subject and 2 to light the green screen. With gain at 0, my exposure is 1/60 f/5.6. I am going to go buy another light that I will use to light the back side of the instructor to make them pop a little along with getting better chroma key separation.

I can alway switch to silver umbrellas or change one of the 2-250w bulbs out to a 500w bulb to get 750w total out of each light, if I need more light. What do you think?

I'm asking because as a still photographer, 1/60 isn't that fast of a shutter speed to be capturing any movement and an aperture lower than f/5.6 may give me too narrow of a depth of field. I know I don't want to change my ISO (gain) as that would affect my output quality.

As far as 1/60 sec. shutter...that's pretty much standard unless you need to freeze the action. In video, you generally don't want moving objects to be razor sharp because it creates an unnatural looking strobe effect when played back. And, unless you are using 2/3 inch chips in your camera, the smaller chips on your video camera will have a wider depth of focus than your still cameras. My suggestion would be to find the sweet spot on your camera's lens and light for that.

If you haven't used halogen lights in a small area before, they can heat up a room pretty fast, so if you do need more intensity, the silver umbrella sounds better than a 500 watt bulb in a small area without good ventilation.

Curt,
You are going to have to get used to video numbers a bit. 1/60 of a second is fine for standard movement unless you want to slow it down without out any blur. You could go with a faster shutter but normal movement will stutter a bit. You may find this acceptable up to a point but maybe not. The camera doesn't change the number of frames it records just the exposure time so shorter shutter speeds have larger gaps between frames and the added sharpness becomes more apparent.
As for video lenses most of them look best between 4 and 5.6. Some consumer HD lenses actually can't go past F8 as it costs too much to design them properly. Often in video we try and shoot F wide open to minimize the depth of focus since the video sensors are so small. You should experiment and see what you like with your rig,

Thanks for the feedback, I just have to learn to separate my still knowledge as it is making me do too much thinking/second guessing when it come to video

Curt.... a still photographer's film background will serve you well, but as you have noted and heard, shutter speeds and F stops can be a little different with video. For example, with the current crop of prosumer cameras it is very difficult to establish a nice DOF - which spawned a small cottage industry of folks making 35mm adapters which allowed you to film off a ground glass using 35mm lenses (it all has to do with image size on the sensor in these cameras).

I think you will find 1/60th to serve your needs just fine.

You are well advised to add a hair/rim light to provide additional separation for your chroma key, and for a nicer overall look to the video.

Chris