DIGITAL VIDEO CAMERA PARAMETERS
Now let’s talk about some parameters of digital video cameras that can still be used as selection criteria.
Number of CCD
Perhaps this is the parameter, at a glance at which two or three years ago, the class of a video camera immediately became clear. Now, the mere fact of having three CCDs in an amateur camcorder says almost nothing. For cameras with three matrices, using a special prism, the image is divided into three primary colors, and each color is transmitted to its own CCD matrix. It is clear that in cameras with three CCDs in most cases an optical stabilizer is used. Only in recent years, Panasonic began to produce 3-CCD cameras with electronic stabilizer, then this “initiative” was picked up by Sony.
To save on the production of video cameras and reduce their cost, manufacturers began to reduce the size of the matrices while increasing the number of pixels on them. The result was not long in coming – some new 3-CCD cameras began to cost about $ 700, but they obviously didn’t shoot too much money. Therefore, the number of CCDs alone doesn’t mean much now – only the presence of three CCDs and an optical stabilizer in the camera can serve as the basis for a choice, but now there is (more precisely, still here and there) only one amateur video camera that meets these requirements , – Panasonic GS400. Indeed, today the quality of shooting provided by it is the highest among portable amateur cameras.
The number of pixels of the CCD matrix
Disputes over the importance of this parameter among lovers are eternal. This issue does not cause any discussion among professionals, since the number of pixels in professional cameras has not changed for many years and will not change for existing television systems (it is quite difficult for professionals, more precisely, it is impossible to prove the need to increase the number of pixels).
The reality is this: the number of pixels needed to fix the video image depends ONLY on the television system and amounts to ~ 415,000 for PAL, ~ 350,000 for NTSC. For HDV-cameras, the number of pixels depends on the resolution supported by the camera and, of course, several times higher than for SD camcorders.
If the parameters of the video camera indicate approximately 800,000 and a larger number of pixels, then this definitely indicates only that the type of image stabilizer in the camera can be electronic or the number of pixels is increased for the sake of being able to take high resolution photos. Such a large number of pixels in the CCD has nothing to do with video quality.
If the number of pixels in the SD camera is more than 1,000,000, then this means that the camera allows you to take pictures (only pictures!) With a resolution determined by the number of pixels in the CCD and not the television system, and save such pictures to a removable memory card ( Memory Stick, SD, MultiMediaCard, etc.). In addition, modern cameras use matrices with a large number of pixels (more than 1,700,000) to form one pixel of the final image from information from four neighboring pixels, thereby trying to minimize the negative effect of a large number of small pixels. To do this, manufacturers install quite powerful specialized image processing processors in the cameras, such as Canon DIGIC DV, for example.
If the specification on the camcorder indicates the number of pixels equal to that necessary for fixing the image (see above), then this indicates that the camera has an optical stabilizer – but such cameras, with the number of pixels of 420,000 (PAL) and costing up to $ 2000, manufacturers now simply do not offer us.
The conclusions are quite simple: you need to understand that the quality of photographs of a digital video camera with the maximum possible number of pixels in a CCD (today it is four million real pixels) will be worse, and noticeably worse than that of a digital camera close in parameters. Unfortunately, in pursuit of a growing sales market, camcorder manufacturers are constantly increasing the number of pixels in the CCD, but at the same time, the matrix size is left the same or even reduced, since increasing the matrix size increases the cost of the camera. The calculation is made on an ignorant buyer, who really in most cases believes that the more pixels, the better. The result, however, is often the exact opposite.
Since the area of the matrix remains the same, the area of an individual pixel decreases, therefore, the light flux incident on it decreases and, accordingly, the real sensitivity of the camera decreases. Manufacturers, of course, coquettishly hint at progress in technologies that improve the sensitivity of the matrix and reduce its level of intrinsic noise, but technology improvements equally affect matrices of all sizes. For some reason, in professional cameras, the same manufacturers do not reduce the matrix, despite the improvement of technology.