Don't Use Megapixel if Subjects Are Moving

Published Nov 01, 2011 00:00 AM
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Don't use megapixel if subjects are moving - such is the implication of an independent international test program who warns that megapixel video subjects can start looking like a banana if they are moving. They claim their "conclusions from the results are fairly straightforward. Megapixel and HD cameras are great if the subject is not moving." This, quite clearly, fallacious assessment, is an unfortunate but direct result of the games that megapixel camera manufacturers continue to play.

There is nothing inherently blurry or problematic about using megapixel cameras with fast moving objects. However, manufacturers realized that if, by default, you slow the shutter at night the whole image looks brighter and displays less visible noise out of the box. Indeed, they quickly found that most naive users immediately concluded that the brighter, crisper image meant a superior camera (something our poll results confirmed).

On the other hand, when the shutter is slowed, moving objects can blur, sometimes very badly, resulting in worthless video. Here's an example of a traditional shutter and an aggressive slow shutter:

Now, this tester should be given credit for not falling for the first obvious trick of simply concluding that the brighter camera is the better one. On the other hand, criticizing megapixel because of manufacturer default shutter speeds is the opposite error. As we pleaded nearly two users ago, all camera tests and comparisons must normalize camera shutter speeds.

While manufacturers make up fancy names for their shutter speed setttings like 'Moonlight' mode or 'LightGrabber', there is no technological difference between the offerings. Essentially every professional IP camera allows for setting the maximum shutter speed. The big difference comes in the defaults, which can vary by nearly 500% in length - a massive difference.

Blurring is a real issue but it is primarily a function of shutter speed / exposure. Make sure you identify the default shutter speed and adjust appropriately. This will allow you to balance the amount of light you capture vs the level of blur you face.