Megapixel Camera CheatsheetBy John Honovich, Published May 12, 2010, 08:00pm EDT
Determining how wide a field a view a megapixel camera can be tricky. Thankfully, IQinvision recently releaed a 'cheatsheet' to simplify solving this problem.
Both are good but I especially like the one page pdf. Print it out and keep it by your desk.
Even if you have never used a megapixel camera, this sheet is a good thing. You may not have used one but you certainly are going to do in the future. This sheet is a quick and easy to gauge how megapixel cameras will work in different applications.
With analog cameras, the decision was a lot simpler:
- 1 fixed camera
- Multiple fixed cameras
You would select a PTZ when the area became too big - parking lots, lobbies, courtyards, etc. Everything else, select fixed cameras to cover key chokepoints.
You never needed to be concerned about resolution. It was one resolution fits all so you made do with what you had.
The Megapixel Future
With megapixel cameras, you suddenly have a new selection problem. Do you choose a 1, 2, 3 or 5 megapixel? (Certain vendors already have 11 and 16 megapixel so expect even that to become more widespread).
For those of you who learned from Charlie Pierce, you will remember personal identification (object 1/10 the field of view) and action identification (object 1/20th the field of view). These identification levels map nicely to IQinvision's General Surveillance and Forensic Detail. (sidenote: Actually, I would prefer the use of Charlie's term - they are clearer and have the benefit of a generation of techs knowing them)
You can then use the IQinvision chart to determine which cameras and how many cameras you need to get either. You can also see what you would need to move from simply getting action identification to getting personal identification (something that was not practical historically).
Finally, if you factor in the price differentials in cameras you can start building an ROI case of moving from action to personal identification.
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