Here’s a look at the 16 VGA cameras vs. one 5MP camera scenario.
Here is a look at progressive scan vs interlaced images.
Despite a decade of nay saying and multiple players coming and going, megapixel technology is now mainstream. However, only a few of the megapixel players appear to be investing in the product development, support and quality control required for long-term success. Further, even as megapixel has gone mainstream, misunderstandings and misinformation continue to hamper a clear understanding of this technology’s powerful potential.
The Pre-Megapixel Era of Equality is Over
Today, there are a number of megapixel network camera manufacturers who would have end-users believe that all cameras are created equal — and if you believe that, I have some outstanding beachfront property for you in Death Valley. The truth is, not all megapixel cameras are created equal, and that makes it difficult to figure out which camera is right for you. The Pre-Megapixel (CCTV) Era was much easier — you designed the system around the DVR since all cameras were, truly, pretty much the same. Whether you bought your CCTV camera from company X or company Y, you were more than likely getting a camera that used the identical system on chip imager made by company Z.
In the IP video space, things are quite a bit different, and more often than not, integrators and designers are now building their systems around the cameras, not the recording device. In the Pre-Megapixel Era, it was easy because you knew that if you wanted to recognize a face or read a license plate (forensic detail); you could only cover a 16-foot-wide area, regardless of what camera you used. So in the good old days, you chose the cheapest camera that you knew to be reliable. In modern times, camera resolutions vary considerably, so selecting the right camera requires a bit more thought because you do not want to buy a camera that has too much or too little resolution for your application.
As megapixel technology is increasingly among the range of choices for most end-users, it is important to clear up some of the more prominent misunderstanding or myths out there today. Here are three of the more common pieces of misinformation about megapixel cameras:
Megapixel Myth #1: When Megapixel isn’t Megapixel
So what are the differences between today’s cameras? There are a number of factors to consider. First, from a specification sheet perspective, we look at a camera’s resolution. Cameras today can vary from VGA to tens of megapixels, so one megapixel camera is not the same as the other. Some manufacturers have gone so far as to call a VGA camera a 0.3 megapixel camera. That’s a bit like calling your little kitty a lion — it’s not even close.
Let’s say you need to cover an area 64 feet wide by 48 feet deep at a forensic level of detail (40 pixels-per-foot). Taking some liberties to simplify this example (lenses don’t actually deliver a square field of view), you would need 64 x 40 pixels wide (=2560) by 48 x 40 pixels deep (=1920) or a total of 4,915,200 pixels (2560 x 1920). If you use a 0.3 “megapixel camera” (translation: VGA camera at 640 x 480), you would need 16 of them to cover the desired space. If you use a 5-megapixel camera, one will do the job (see the graphic above).
Now let’s calculate costs. If you choose a VGA camera that costs about $200, you will pay 16 x $200 = $3200. Divide the cost by the total number of pixels and you come up with $0.00065/pixel. Alternatively, if you select a high-end, reliable 5MP camera that costs about $1200, using the same calculation, we find your cost would be $0.00024/pixel which is 63-percent cheaper — and that’s before you consider installation costs like cabling, power and housings! What’s the point? Just because a company may use the term megapixel in its marketing does not make it a megapixel camera.
Megapixel Myth #2: HD the Next Megapixel?
Some companies’ second attempt to baffle you is to imply that HD (high definition) and megapixel are different — they are not. Megapixel means “million pixels” and a camera either has a million or it does not. It is pretty easy to determine. HD is a term used to describe anything that is higher than standard (D1) resolution (this fact verified by that unimpeachable source, Wikipedia) and is now typically associated with a widescreen format like 16 x 9, but does not have to be.
What are we driving at? An HD camera is not necessarily a megapixel camera, but a megapixel camera is always an HD camera. The easiest example to demonstrate this point is to look at an HD720P camera — is it megapixel? Let’s do the math. HD720P is 1280 x 720, or 921,600 pixels, which is not quite a million pixels, so technically this HD camera is not megapixel, although it is pretty close. On the other hand, the lowest megapixel resolution camera will always be higher than D1 and is therefore always HD. Megapixel was HD long before all the recent marketing trying to tell us HD is something new and wonderful.
Megapixel Myth #3: Interlaced is Not Very Progressive
The last Megapixel Myth to be beware of is the manufacturer that leaves off important details like what type of imager they are using. If someone talks about an HD1080 camera, they are only giving you half the story, is it HD1080p or HD1080i? The “p” stands for progressive scan, which delivers much higher quality video, especially when there is motion. HD1080i cameras, on the other hand, are “interlaced” cameras that stitch two low-resolution images together to make a high-resolution picture, which often results in poor image quality when there is scene motion. It is interesting to note that one network camera manufacturer that was previously quite outspoken on the limitations of HD/megapixel and the poor image quality of interlaced video, recently introduced an HD1080i camera that is megapixel and uses interlaced technology. I wonder what changed? What has not changed is that progressive scan is still superior to interlaced.
In the end, if you are in the market for an HD/megapixel camera, the best thing you can do is try before you buy. Take a look at the manufacturing quality and design elements. Are you looking for an inexpensive, plastic consumer-grade product designed with off-the-shelf housings/boxes so it is as cheap as possible, or do you want an industrial, rugged package that reflects the manufacturer’s investment in quality and durability?
When considering features, are you jumping on the bandwagon of the latest marketing hype or are the features those you really care about and will use? There are most definitely market-valuable features — like analog out — that save time and money on installations and enable you to integrate directly with public-view monitors and legacy CCTV systems. Or, there is On-camera storage that allows cameras to act as fail-over recording devices if there are problems with the network so you do not lose any video.
The important thing to keep in mind here is not to miss the forest through the marketing-hype trees. By trying before you buy you are evaluating and “feeling” the design, construction and features the camera offers against what you actually want for your application.
So, the truth about megapixel? It is here to stay, and if you choose a quality company, megapixel offers a lower total cost of ownership for most installations while providing end-users with image quality and performance that meet and very often exceed their expectations.
This article is a follow-up to Paul Bodell’s popular three-article series, "The Truth about Megapixel," which appeared exclusively on SecurityInfoWatch.com and is available by searching the site archives. Mr. Bodell is Chief Marketing Officer for IQinVision.