What is a high speed video camera
What's so special about a high speed video camera?
A high speed video camera is designed around a specialized image sensor optimized for the unique requirements of high speed imaging.
Like many things, the design of an image sensor involves many trade-offs: light sensitivity, noise, size, and readout speed are the main ones. Each of these trade-offs interact with the others. It just isn't possible to take great slow motion videos with a sensor optimized for still photography. Similarly, you can’t take great stills with a sensor optimized for high speed video.
All existing consumer and prosumer cameras use sensors optimized for the still end of the spectrum and it is a good choice for that market.
Readout speed is the primary difference between slow motion sensors and other sensors. Our sensor reads data out at ~1 GByte/sec. It’s necessary for high speed video, but comes at a price: higher power, more image noise, complicated interfaces, and a complicated image processor designed to handle all that data.
A global shutter is the second difference. A global shutter exposes all the pixels simultaneously, just like an intra-element leaf shutter in a still camera. All consumer and prosumer cameras with a CMOS sensor have a rolling shutter. Just like a focal plane shutter, different pixels in the image are exposed at different times. This is what causes the jello effect or the bizarre distortion in the image below. So, why don’t all cameras have a global shutter? It’s a tradeoff: global shutters are more expensive, higher noise, less sensitive to light, and lower resolution. Rolling shutters work OK as long as there isn't a lot of motion, but with a high speed camera, we want a lot of motion.
I want 4K, and faster and cheaper
Ahh … don't we all. For now we think this the optimum price/performance point for an introductory product.
Higher performance is always possible, but it always comes with a non-linear price. Cars are an example of this. To first order, a car's acceleration correlates best to horsepower. If you like fast cars, horsepower is the first specification you look at.
Now consider two examples: A Honda Civic has about 140HP and costs $18K. Thats $128/HP. A Ferrari 458 has 605HP and costs $233K. That's $385/HP. If you have to have the very fastest and can afford it, the Ferrari is great, but millions of drivers love their dependable and affordable Civics.
For high speed cameras, the sensor readout rate is like horsepower in cars. If you want high resolution and high frame rate, it's the first spec you look at. Here's how we stack up: The edgertronic readout rate is 945MB/sec and costs $5495. That's around $6/MB/sec. An 4K Phantom camera readout rate is 12GB/s readout rate and costs about $250,000. That's around $21/MB/sec. Just like cars, there's what we dream about owning, and what we can afford. The edgertronic provides a high level of performance at a price many can afford.
What can you do with a 5 microsecond shutter?
Some things are fast moving: A bullet traveling 100 feet per second will move 0.06" in 5 microseconds.
Some things are very bright and can't be captured with a high speed flash. The flash arc of an overloaded circuit breaker is one such example. Only with a high speed shutter can you capture these types of events.