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. Personally you are going to want a frame rate that is going to use all available light as efficiently as possible. You should do a few test videos in that environment prior to the actual shoot. Your spot meter should be on so the available light in the room does not overpower the sensor. I would set the ISO at around
Probably 2.7K superview 30FPS would work well in low light or perhaps 2.7K 24FPS (assuming no slow motion is warranted) this will allow use of the 4.3 and stretches it to 16.9 to keep your footage in video format.
If this is a one time shoot, I strongly suggest that you shoot a test video first and view it on a desktop/laptop or whatever to insure the quality of the video.
You didn't specify what camera you are using so I am guessing here but you should also consider other settings as well. First would be Protune. Since you are using FCP you will likely do your own color grading. In that case I would use Protune in "flat" and make adjustments in post.
White balance in this case will be trial and error, or you could use "auto" but give the camera a chance to normalize to the correct setting on each touch of the record button. Or, you can try it at 5500 or 6500 both are good in cool lighting like incandescents and fluorescents.
ISO should be a consideration as well. Lower ISO's will result in darker footage but the video will be less noisy. If you are using a Hero 4 you should try an ISO of 400, 200 and 100 to see what is best for your lighting situation. Again, practice!
Sharpness, should be set at low or medium and adjusted in post.
Exposure, this should be left at +0.0 or perhaps +0.5 but you need to play with that setting.
You should have a plan on how to test these. Plan your settings in advance, maybe right down two or three combinations and try them, view them and you will be prepared before you shoot the actual video for best results.