# ISO sensitivity rating



## sowboon (Jan 12, 2009)

Hi,

I have a CMOS sensor with sensitivity of 600mV/lux.sec. How to calculate or convert it to ISO number?

The frame rate are available in 15fps, 30fps, 90fps. 
How to determine the exposure time in term of second?

Thanks for your reply.


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## davebmck (Jan 12, 2009)

The sensitivity is a measure of the sensor's sensitivity to light.  It has nothing to do with the iso number.  The camera is capable of being set at a number of iso settings.  You need to look at the specs on the highest and lowest iso settings available on the camera.

The frame rate is how many pictures the camera can take in one second.  It really has nothing to do with the shutter speed, except for the fact that the shutter speed needs to be fast enough to allow the frame rate.  Obviously, you can't take 15 frames in a second if your shutter speed is set at 1 second.


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## elemental (Jan 13, 2009)

Is this for still photography or videography?


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## frXnz kafka (Jan 13, 2009)

elemental said:


> Is this for still photography or videography?


Judging by the framerates, I'm going to guess videography


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## Garbz (Jan 13, 2009)

The sensor doesn't have an ISO rating, the system does. You would need to know everything about the system including the amplification, and ADC process to calculate ISO.


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## TamiyaGuy (Jan 13, 2009)

I'm not too sure about the sensitivity (I suspect Garbz is right, though ), but for video cameras, just like still cameras, there is no one specific exposure time; it has to adjust depending on the strength of the light source. However, the exposure needs to be shorter than the amount of frames captured per second. The exposure can be 1/1000s, but it can't be 1/20s if filming at 30FPS.


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