[Tig] fast camera in wind tunnel

[Jim Houston]

On Jan 15, 2007, at 1:27 PM, Rob Lingelbach wrote:


>
> This gave rise to two other questions: what kind of exposure do
> you get at 2 million fps?

So it is about .5 microsecs per frame.
You need an exposure 12 stops better than a 1/500 sec shutter.


CCDs fill up fast with light, it is the drain time to read them that  
slows them down.
So as long as you want only  one set of images from a row of sensors you
can make a very short exposure and get useful info.

The 2 million fps name is just marketing nonsense.

It is just a 500nanosecond multi-frame camera.
It can't produce 2 million frames.  How many frames it can do
isn't clear. Some film 2 million frame cameras can do 200-500 frames
at a time.  Others can only do 25 film frames.

> Do you have to light the object at
> a brilliance almost unheard of for the camera's sensors?

Yes.  high power strobes are fine.  There are other ways as well.

Jim H.