Best Shutter Speed for 24P Green Screen shooting?

[citizenspain]

With a 1/60 shutter speed on a Panasonic DVX-100A shooting 24P green screen tests, fast movements blur into a green color which gets keyed out in the posting process (ex. I had an actress stand still and wave her arms up and down quickly - her arms disappear when I key out the green). I have the screen evenly lit and am able to get a pretty good image in Final Cut Pro, aside from the diappearing arms.

Does anyone have any tips for a scenario like this? I just want to be ready for various problems that may arise when I move beyond standard screen tests.
Thank

 

[Scottdvx100]

If you change the shutter speed then you're likely to get strobing and an image that doesn't match your background.
Try working with your settings so you get a gradation on any blur. Right now you're clipping too hard. FCP isn't the best at keying.

 

[Policar]

Unless you want some special effect a la Gladiator or Saving Priate Ryan, in 24p, you should be shooting with a shutter speed of about 1/48th-1/60th of a second. Some 16mm cameras run at 1/60th while some run at 1/48th and I can only assume the same holds true for 35mm cameras. Of course, some cameras have adjustable shutter angles, and the "shutter angle" is inherently SLIGHTLY different from "shutter speed" in the way in which the frame is exposed.

The fix here is to use a good keyer like Keylight. There are other cheaper (and arguably better) keyers, too, but I don't know what they are since I don't use them. With software like Keylight, you can easily capture motion blur or even translucent objects. I've greenscreened water (not ENTIRELY convincingly due to issues with a lack of refraction) before. And it was pretty painless--easier than keying in FCP. I think there are some great keyers for a few hundred dollars so it really might be worth looking into one of them for your project. Otherwise, shooting with a shutter speed of 1/1000th of a second or something WILL work, but your footage will have bizarre motion issues you won't want to deal with. They can probably be fixed with motion blur software, but that's an iffy idea in the first place and a far more complex fix than just using good keying software.