3 Key Differentiators in Megapixel Camera TestingBy John Honovich, Published on May 20, 2009
3 important differentiators among the cameras I am currently testing:
- Effective or 'true' resolution: The stated pixel count (1.3MP, 2MP, etc) is proving to be a misleading metric to judge cameras. More pixels often do not mean better image quality. This is a critical element as better image quality (the ability to see smaller details) is the key driver in the use of megapixel.
- Bandwidth consumption variation: I see wide variances in how much bandwidth is consumed, both depending on the scene and, more interestingly, between manufacturers. Some manufacturers are using 2Mb/s for a given scene while other need 6-8Mb/s. This could be a major factor in choosing cameras as the differences in storage could be quite expensive.
- Handling low or changing bandwidth levels: Some cameras have significant problems with insufficient bandwidth. The image will break up almost entirely under these conditions. It is essential that surveillance cameras are robust to lower bandwidth. While it's obviously understood and accepted that with less bandwidth, either frame rate or quality will suffer somewhat, the connection and the basic image must remain.
These are certainly not the only 3 issues - just issues that generally receive less attention. Additionally, I am still in the process of investigating CPU utilization.D Finally, low light/WDR remain important issues for megapixel as they do for all surveillance cameras.