Nikon D3100 Video Settings?

I'm trying to film videos on my new Nikon D3100 but when I'm in manual mode and i'm changing my shutter speed or ISO it does appear to change the video appearance at all. The only things that seems to change the look of the video at all. Changing the settings does, however change the look of the stills as it should. Am i doing something wrong or does the camera lack the capabilities to change video settings?

Changing ISO and shutter speed will mostly affect the brightness of your image. If you want to have a brighter image the first adjustment you should make while in manual mode is the aperture of your lens (if using an autofocus or kit lens make sure the lens is also set to manual mode MF) Your aperture will be limited on each lens with an f-stop rating. A low f-stop means the aperture will be open more and allow more light in. A high f-stop means a smaller opening and less light (generally higher f-stop values are used when filming outdoors). All of these changes can be made while in live view in the D3100. A general rule of thumb is to have your shutter rate be double your frame rate. If you are filming 30fps then your shutter rate should be at least 60 (although I think the D3100 has a minimum shutter rate of 60 anyway).