Matlab image acquisition exposure value

How is the exposure time calculated from the exposure value that you set? Right now I am setting it to -10, but I'm not sure what the actual exposure time is.

Thanks.

Answer 1

[Walter Roberson]

Exposure value does not indicate the exposure time directly. Rather, an EV of -10 means to expose the picture about 1024 times longer than would otherwise be the case. See http://en.wikipedia.org/wiki/Exposure_value