The difference between DC and DV

DC (Digital Camera) is a digital camera that is used to take a single still photo; DV (Digital Video Camera) is a digital video camera that is used to capture dynamic video images.

Simply put, DC and DV have different uses and different focuses. However, with the development of the two types of products, there is currently a tendency that DC's dynamic video recording function is becoming stronger and stronger. In DV, there are also models capable of shooting 2 million, 3 million pixels, or even higher-precision static photos. Sanyo C Series DC/DV combo stuff. However, such products are only a small part of many product lines, and the market performance is not very satisfactory. So where is the difficulty of DC shooting dynamic images or DV shooting still images?

DC's difficulty as a DV is that it is difficult to achieve high resolution first, followed by the cooperation of photovoltaic systems.

Let me talk about the first point: It is difficult to achieve high resolution. Although the number of pixels in a digital camera is as high as several million, the number of pixels in a single image for dynamic video recording is only several hundred thousand, but dynamic video recording requires several tens of frames per second. The amount of data is very large. The digital camera's image processing chip is designed specifically for the processing of still pictures. It is often difficult to handle dynamic streaming files because DC and DV's image processing chips are dedicated chips and their "high efficiency "From a "feature-specificity", to take into account both sides, either use more powerful processors or sacrifice processing efficiency, while the former means expensive and the latter means low energy. On the other hand, huge amounts of data require huge storage space, so mainstream DVs still use tapes because, even with the high compression ratio of MPEG-4 compression, 512MB memory cards can only store more than 10 minutes of high precision. Video.

The second point: the cooperation of photoelectric systems. When taking a single photo, you can zoom and focus in advance. Accurate is the first requirement. For accuracy, you can even give up a little speed. When shooting a moving image, zooming, focusing, and image capturing are performed at the same time. It is required that the cooperation of the photoelectric system be not only accurate, but also faster, and even the requirement for “fast” exceeds the accuracy. Therefore, DC and DV have different requirements for the optoelectronic system, and it is difficult to take both sides into account. Therefore, although many DCs can now shoot video clips, they cannot perform zooming operations in the middle of the shooting. Many low-end models even lock the focus distance after the video is started.

DV as the DC's difficult point is still the first thing to consider is the resolution, due to differences in people's visual experience, the requirements for dynamic image accuracy is much lower than the static image, the standard PAL format and NTSC video signal, if converted into pixels To express that, the accuracy of a single frame is less than 300,000 pixels, and the video signal of VGA level (640x480, 300k pixels) is already considered to be high-precision, even if the HDTV is HDTV, the single frame is only 2 million pixels (1920x1080). Pixel), so the current mainstream DV is still 800,000 pixels. As far as DC is concerned, the current 3 million-pixel model has gradually withdrawn from the mainstream market, and home products have already reached 5 million pixels.