In Part One I of this article, we focused on sensor size—the major difference in the quality and price of video cameras. Now, let’s look at other features and specs that differentiate the quality of today’s video cameras and camcorders.
One of the major differences in camera systems is their adaptability to integrate into a postproduction workflow. Features for this are normally found in higher-end professional video formats, rather than the less expensive HDV and AVCHD formats found in consumer level camcorders.
For example, with professional level camcorders, such as Sony’s XDCAM system, the user can view recorded scenes immediately on the camera’s LCD monitor with no need to fast forward or rewind. One can then renew shooting without cueing back to the end of the last shot.
Proxy AV allows the user to quickly transfer small files to a laptop for immediate viewing, logging, selecting takes and cut-only editing. These files can be transferred faster than real-time to the studio, allowing editing to begin before the full-resolution video arrives.
As formats improve, so do the bit rates of the recording device. These range from 25 Mbps for the standard DV formats to 50 Mbps for high-end high-definition camcorders. Some more specialized camcorders also offer variable bit rates.
Manufacturers use improved circuitry to process images in more expensive cameras and camcorders. In a top-of-the-line digital multi-format camera, Panasonic, for example, uses 14-bit, rather than 12-bit, analog-to-digital conversion. It also has 38-bit digital signal processing and real-time gamma correction to enable the shooting of extremely "contrasty" scenes.
More expensive cameras also allow precise and independent adjustment of hue and saturation of colors, skin tone detail correction, and more flexible conversion between field and studio operation.
At the top of the range, for example with Sony’s CineAlta F23 camera, 4:4:4 RGB image capture and output is enabled over standard 4:2:2 sampling. This robust signal allows more precise green-screen composting, aggressive color correction and other postproduction tricks.
In the most expensive cameras, color values are never “interpolated” from neighboring pixels, allowing full resolution 1920 x 1080/60 progressive images.
There are many, many feature differences among high-end video cameras. The camera or camcorder should be chosen to fit both the budget and application. Though small, inexpensive camcorders serve well in many applications, although there are huge differences for discerning professionals who want the very best image quality and greater flexibility.
