Debunking Arecont Rep's Megapixel vs Analog CalculatorBy John Honovich, Published on May 09, 2011
One of the most common and dangerous fallacies in IP video surveillance today is pixel / resolution equivalency. For example, many vendors will tell you that a 3.1 MP camera is equal to 10 analog (or SD IP cameras) because a 3.1MP camera has 10 times the number of total pixels. CV Reps, an Arecont rep firm, has taken this to a dangerous level by emedding this fallacy into a spreadsheet [link no longer available].
In CV Reps's spreadsheet, you "insert the number of megapixel cameras in the project. You can then see the number of analog cameras required to deliver the same resolution/total pixels to the project as well as the estimated cost of both. " The image below provides an excerpt from the spreadsheet demonstrating their assumption that (1) 3.1MP camera is equivalent to 10 analog cameras.
The problem with this assumption is that real world test results do not bear out that a 3MP camera is worth 10x an SD camera. Here are 3 excerpts comparing an Arecont 3MP, a Sony 720p and a Bosch SD camera. The results are much closer to a draw than a 10x advantage.
The heart of the problem is the assumption that pixels are the sole driver of visible quality. This clearly is not correct. Our tests show repeatedly that lighting variantions and lighting deficincies can be equal or more important determinants of overall visual quality / details captured.
This calculator provides a false measure of accuracy and precision that belies the fundamental limitations of megapixel cameras.