A User's Guide to Digital Video Surveillance

VIDEO QUALITY


The manufacturers of the CCD's (which is the main guts of the camera) primarily make 2 or 3 basic grades of product in terms of camera lines of resolution. There is a standard resolution for color cameras (which people quote as anywhere from 330 TV Lines to 380 TV lines) a high resolution for color cameras (which people quote as anywhere from 450 TV Lines to 480 TV Lines) and a new standard some refer to as “high definition” (which it is not true high definition – with quotes of anywhere from 520 TV lines to 550 TV lines).  For black and white a 420 line and 600 lines are similarly standard and high resolution, respectively.

The more lines of resolution in the picture, the higher the quality of the picture should appear. You will find many companies will quote a higher number of lines to gain a marketing advantage, when in fact the information is incorrect. The CCTV camera business is dominated by 2 companies that control more than 95% of the CCD market; Sony and Sharp. It was very similar to the television tube market, which despite the name on the set; it was either a “Trinitron” tube from Sony or a Black Stripe tube. These companies make a limited number of CCD’s for the surveillance market.

In our opinion, Sony offers a much higher quality picture and richer colors than Sharp. There is a significant price differential to go along with it. In fact, in our opinion a standard resolution Sony CCD appears better than a high resolution Sharp CCD.

This brings us to another issue. You will see some websites or companies publish specifications that are much higher than others. Be suspicious, as they should pretty much be the same; since the majority uses the same identical components and all they do is assemble. Some unscrupulous individuals will also try to sell you product represented as one component when in facts it's another.  The 2 main components of the CCTV camera are the CCD and the Integrated Circuit (IC). So they may use a Sony CCD and a cheap IC. This is one of a handful of concerns.

This is a problem since the consumer has no way to easily identify whether it's a Sony or Sharp CCD or it's a standard or high resolution. It all comes down to credibility. Since the CCD’s and IC’s are commodities most pay similar component costs. Accordingly, suspicion should be placed on anyone selling dollar bills for 75 cents, meaning a similar product is being sold by one company well below the price point of the rest of the market. The only way to be able to truly identify the specifications of a product is if it is a well-known branded product and not a “blank box or “brand-x.” The Internet creates part of the problem as just about anyone can hang up a shingle and promote themselves, as someone even if they are working out of a basement.

CCD quality is but one concern. We talked about earlier lux ratings. Even a high quality CCD has certain limitations. As such, you need the proper CCD for the job. Lower lux CCD’s are more expensive and when you get into the area of day/night CCD’s they can be significantly more than standard CCD’s but not prohibitive.

CMOS cameras or digital cameras are referred to in terms of megapixels and are very uncommon as of this date due to the prohibitive costs associated with equivalent product to those of the CCD. There is a lot of confusion with respect to CMOS cameras. Probably the cheapest cameras in the market and the most expensive cameras in the market are CMOS cameras. There are CMOS cameras like your webcam that are made into CCTV cameras, which are inferior in quality in every respect and there are high megapixel digital cameras, which can cost in the $1,000’s, which are not necessarily much better. They are at opposite ends of the spectrum. CMOS cameras and the underlying IP camera technology have a long way to go.
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