The Side Effects of High ISO Videography

I'm often still a little shocked at just how light sensitive the Alexa really is. When I'm at my cart evaluating images shot with a fast lens at ISO 800, they are often far brighter and better defined than what you see on-set with your own eyes. When the gaffer is wishing he had 40 watt open face lights, you know you're in a brave new world. Working at such a low foot-candle becomes challenging in new ways and as I've discovered, there are a few fascinating side effects.

Red Eyes in Motion Picture - an effect that used to be very difficult to achieve on film is now far easier. For better or for worse.

When your key light source is a scant 3 foot-candles, the human eye naturally dilates considerably to accommodate such low light. When you have a source close to the lens such as a ring light and your subject's pupils are in this state, you can very easily end up with eyes that look like something like this (model on the right) -

Alexa v3 @ ISO800, Cooke S5 @ T1.4, 2.75 Foot-candles