Tutorial: Improving Video Color Quality

The alternative to CMOS is the older standard, CCD, and three-CCD solutions. Many people know the term CCD, but what is it? Well, again, it’s not a know-or-fail thing, but it helps to understand the complete workflow. The CCD is a solid-state chip that turns light into electric signals. In a full-frame device, all of the image area is active, and there is no electronic shutter. A mechanical shutter must be added to this type of sensor or the image will smear as the device is clocked or read out. The sensors respond to 70% of the incident light, making them far more efficient than photographic film, which captures only about 2% of the incident light.

Most common types of CCDs are sensitive to infrared light, which allows zero lux (or near-zero lux) video recording. Many CCDs, like CMOS sensors, use a Bayer mask over the CCD. Each square of four pixels has one filtered red, one blue, and two green. The result of this is that luminance information is collected at every pixel, but the color resolution is lower than the luminance resolution.

Better color separation can be reached by three-CCD devices (3CCD). Each of the three CCDs in these devices is arranged to respond to a particular color. Another advantage of 3CCD over a Bayer-mask device is higher efficiency (and, therefore, higher light sensitivity for a given aperture size). This is because, in a 3CCD device, most of the light entering the aperture is captured by a sensor, while a Bayer mask absorbs a high proportion of the light falling on each pixel.

CMOS is allowing a cheaper entry into the HD and HDV realm. This is why technologies that enable the HDV movement are available at an affordable price, unlike those that enable the HD CCD movement. Neither technology has a clear advantage in quality. CMOS can potentially be implemented with fewer components; they use less power and provide data faster than CCDs. However, CCD is a more mature technology and is, in most respects, the equal of CMOS.

Choosing the Right Camera
All cameras have their advantages and disadvantages. It doesn’t matter if they are a camcorder, dockable, or box (industrial) camera. The typical camcorder is the video professional’s bread and butter. Camcorders are used in probably 90% of the industry because you can go to tape instantly or to a hard drive in some cases. Along with going to tape, they provide FireWire and analog outputs. As mentioned earlier, with the emergence of new technology, we are seeing prices drop, allowing an easier movement into the HD world.

Another trend in the camera movement is to go away from camcorders to dockable cameras. Dockables offer the advantage of changeable recording formats. Maybe you have an event that requires a videotape recorder (VTR) back or camera control units. Obviously, dockables offer greater flexibility in these situations. They aren’t the cheapest route to go up front, but one camera can do the job of three or more camera formats. So in the long run, if you can afford this solution, it can pay for itself relatively quickly.

If the dockable price is too high or you want to go for a smaller-sized camera, the box (industrial) camera is a great option. You can set these up to be controlled remotely or in a studio configuration. Their prices, in most cases, are affordable, and you can more than likely use the lenses you already have. The major drawback is that there is no camera back or VTR that is already on board or that can be attached. But then again, you’re not format-dependent. You can use a VTR of any format, and you can also hook up a CCU to give you more control over the black levels and color saturation.

With so many camera options, what format should you use and what is best for the web? Well, you can use the three main formats: DV, HDV, and AVCHD. It really depends on what your shoots are now and how you want to position yourself for the future.

Now, HD streaming is still small but growing. With more people getting cable modems that can handle higher bitstreams, HD is becoming more attractive. Granted, we are a long way from the days of postage-stamp-sized video, but wouldn’t you love to see a great-looking 1080 video stream at full frame rate? It’s coming, but who are the first players going to be?

If the cost of HD still scares you and you don’t do enough other projects that can justify a full-blown HD camera, then the HDV route is probably the best way to go—just go progressive and skip the interlaced route. Keep in mind, however, that a progressive HDV camera like the JVC HD200 shoots the same resolution (1280x720) as a non-HDV HD camera like the Panasonic HVX200. Most TV and computer monitors are going away from cathode ray tubes (CRT). If you need to do interlaced video, go ahead and change from progressive to interlaced in postproduction. You will be happier in the long run.