These days, the differences and prices between professional HD video cameras have become quite confusing. Sure, all professional quality cameras look good to the naked eye on controlled monitors, but there are significant variations in quality that dictate price.
Among the key defining ways that digital HD cameras differ is in sensor size. Currently, there are three leading sizes: 1/3-inch, 1/2-inch, and 2/3-inch. Three of the larger 2/3-inch sensors are found on the most expensive and sophisticated cameras—including digital cinema cameras. A single one-third inch sensor is found on low end professional cameras.
All things being equal, larger image sensors enable higher sensitivity, lower noise, and wider spatial resolution. They also result in shallower depth of focus for selective focus effects, which could make smaller, cheaper digital HD cameras better for outdoor, documentary style shooting.
For example, Sony’s new XDCAM HD camcorder, the PDW-700, uses three 2/3-inch type CCDs. Other XDCAM HD camcorders use 1/2-inch type CCDs. As Sony wrote in a FAQ about these camcorders: “Note that in real-world comparisons of actual camcorders, ‘other things’ are hardly ever ‘equal.’ ”
Sony said it introduced the 2/3-inch XDCAM camcorder to meet customer demand for higher-end production equipment that also delivers the workflow advantages of tapeless recording. The PDW-700 2/3-inch camcorder uses a 50 Mbps version of the MPEG-2 Long GOP.
Panasonic, in its high-end AK-HC3500 HD television studio camera, also has three 2/3-inch sensors, backed by a 38-bit digital signal processor and a 14-bit A/D converter. The company’s Varicam, designed for digital HD cinematography, offers a higher standard of precision color, detail, and gamma processing to ensure optimum picture quality that is repeatable and transferable to all Varicams.
The high-resolution demands of digital HD cinematography have “pushed the envelope” of HD camera performance. Most digital HD acquisition works within the ITU-R BT.709, standard, which specifies 4:2:2 sampling and Y/Cb/Cr encoding. The Sony F23 cinema camera exceeds this with full 4:4:4 RGB image capture and output. It uses the HDCAM SR recording system, which features full-bandwidth, 4:4:4 RGB color sampling. Sony said this results in “superb tonal gradation.”
Red Camera seeks to trump others with its Mysterium Super 35mm cine sized (24.4×13.7mm) sensor, which provides 4K (up to 30 fps), 3K (up to 60 fps) and 2K (up to 120 fps) capture. This is with wide a dynamic range and color space in 12 bit native RAW.
At 4K, that’s more than five times the amount of information available every second and a vastly superior recording quality. Mysterium boasts greater than 66db dynamic range thanks to its large 29 sq. micron pixels. That’s 12,065,000 pixels.
In the coming weeks, we’ll look at factors that differentiate HD camcorders at various prices and configurations.
