Red Dumonde Chart
Click on image to view larger picture.
Red Dumonde Test
Last Tuesday (11-15-2006) David Stump ASC was over at the RED facility and did a series of test shots last week with the RED prototype; "Frankie".
Tests included latitude testing and a greenscreen shot.
About the test chart shot:
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.
About the Dumonde chart:
Multi-Tasking, Multi-Standard Charts! Whether used in production or in post, new ChromaDuMonde charts generate precise hexagonal-shaped displays for HD, SD and NTSC television images. After gamma is set using the charts’ precise crossed grayscales, colorimetry can be set to HD, SD and NTSC standards by positioning the charts’ 24 color signals in their boxes and intermediate positions. While designed for HD TV calibrated offsets are provided for the purists who want to know the theoretical colorimetric differences between the systems.
Today's DPs, producers, digital/special effects technicians and camera operators increasingly view DSC charts as necessities for optimizing their high performance cameras, and the production value of their images. ChromaDuMonde is the latest addition to DSC's family of production-friendly CamAligns.
In Engineering ... Use ChromaDuMonde to evaluate and adjust a video camera’s color matrix and gamma with a waveform/vectorscope. Charts are especially useful for accurately reproducing skin tones, custom and difficult colors - purple and turquoise, and other colors which occur at prism crossovers.
In Production ... Check and adjust cameras on the fly, and immediately see the effect of any hue changes on surrounding colors. When producing "green screen" and other digital/special effects, ChromaDuMonde charts provide precise information about how camera hue adjustments are affecting the full gamut of color reproduction. Image quality and consistency can be enhanced by recording chart information to tape or film, and using it in post as a baseline production reference. For scene-to-scene consistency, record a few chart frames with every lighting change - to facilitate/expedite color-correcting, matching footage, and digital/special effects. Chart information provides a foundation for users’ creativity and innovation!
Tests included latitude testing and a greenscreen shot.
About the test chart shot:
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.
About the Dumonde chart:
Multi-Tasking, Multi-Standard Charts! Whether used in production or in post, new ChromaDuMonde charts generate precise hexagonal-shaped displays for HD, SD and NTSC television images. After gamma is set using the charts’ precise crossed grayscales, colorimetry can be set to HD, SD and NTSC standards by positioning the charts’ 24 color signals in their boxes and intermediate positions. While designed for HD TV calibrated offsets are provided for the purists who want to know the theoretical colorimetric differences between the systems.
Today's DPs, producers, digital/special effects technicians and camera operators increasingly view DSC charts as necessities for optimizing their high performance cameras, and the production value of their images. ChromaDuMonde is the latest addition to DSC's family of production-friendly CamAligns.
In Engineering ... Use ChromaDuMonde to evaluate and adjust a video camera’s color matrix and gamma with a waveform/vectorscope. Charts are especially useful for accurately reproducing skin tones, custom and difficult colors - purple and turquoise, and other colors which occur at prism crossovers.
In Production ... Check and adjust cameras on the fly, and immediately see the effect of any hue changes on surrounding colors. When producing "green screen" and other digital/special effects, ChromaDuMonde charts provide precise information about how camera hue adjustments are affecting the full gamut of color reproduction. Image quality and consistency can be enhanced by recording chart information to tape or film, and using it in post as a baseline production reference. For scene-to-scene consistency, record a few chart frames with every lighting change - to facilitate/expedite color-correcting, matching footage, and digital/special effects. Chart information provides a foundation for users’ creativity and innovation!
