David Stump ASC RED Greenscreen Over Under Frames
Details of 11/07/2006 Shoot
Subjects were DSC Chroma Du Monde, DSC Focus Star, MacBeth Color Checker, and David Stump ASC “One Eyed Jack” HD exposure ball. Lens was a Cooke S-4 65mm S/N 65-0937. Focus distance to subject was 15 feet, greenscreen distance was 28 feet. Greenscreen was lit with 6 x 4 globe Kinoflo units at 45 degrees to screen at approximately 8 foot distance, using chroma green globes, no gels. The greenscreen used was a Composite Components Spandex Green 12’ x 12’ lit to EV 9.3 @ ASA 200.
Subjects were cross front lit with chimera 2K blond tungsten from 45 deg. left side f4.8. Fill from 1K tungsten on camera right to f 3.5. Cross backlight from 600w tungsten tweenie on camera left to f 2.8 and on camera right from tungsten 1K to f 3.5. Average color temp was 3100 deg. Kelvin, no color gels on any of the lamps.
I conducted a preliminary exposure test to determine how to rate the camera’s ASA which I determined from the test to assume at ASA 200. Greenscreen wedge test was evaluated in Adobe CS2 Photoshop which indicated that a green exposure of 58% was achieved at f4.8 while holding red level in the screen at about 8% and blue level in the screen at 26% (see attached chart) which I determined to be the optimum level of exposure and color difference for pulling mattes from the material.
Subjects were lit for f 4.8 @ ASA 200, 180 shutter at 24 fps, 1/48th sec. exp. time. Foreground exposure was metered with Spectra Cine Pro IV meter s/n 11752 calibrated 5/2006 by Nassar Zaidi of Spectra Cine. Foreground color temperature was metered with Minolta Color meter II s/n105677 calibrated 5/2006 by Nassar Zaidi of Spectra Cine. Greenscreen was spot read with Pentax Digital Spot meter s/n 103772 also calibrated 5/2006 by Nassar Zaidi of Spectra Cine.
Camera Gain setting was 5447 (standard neutral setting) and camera was left at it’s native 5000 Kelvin color balance. The native 12 bit bayer images were debayered and converted to uncompressed RGB 16bit tiffs in a prototype RedCine application developed by Graeme Nattress. The Redcine application added 2.2 gamma, black offset correction, some small white balance correction, and added a small contrast curve. No dead pixel correction was applied.