I am helping shoot a series of interviews on a green screen with a sony f800. I have a variety of skin tones to shoot and am just wondering if people have advice for really nailing the exposure on both the green screen and the subject. The lighting is very flat. I have it with a 17inch monitor with a waveform and I have been keeping the lighter skin tones a bit under 70ire and the darker skin tones around 50. But I still feel like there is a lot of guess work on my part and i'm not sure how to fine tune it to be perfect as far as targeted exposure levels with the waveform and zebra stripes.
Thank you for any advice!