Exposure Compensation: How does the camera work?

[tmyuen]

I think I understand the use of EC, but I'm just wondering how it actually works within the camera. Say, I set EC to +1, does the camera adjusts (extends) the exposure time? or adjusts (raises) the ISO value? or uses some other tricks to give an effect of higher exposure value?

[Lindolfi]

Depends on the setting of the camera. Aperture Priority (Av on Canon) adjusts the shutter time, while Shutter Priority (Tv on Canon) adjusts the aperture. In Program mode (P on Canon), both are adjusted, while in Automatic mode (green rectangle on Canon), there is no exposure compensation, but only in this latter mode, ISO can be adjusted, depending on the light conditions.

The other camera brands have similar settings and behaviour. Hope this is of use to you

[atvinnys]

tmyuen

check the rest of the forum, there are a couple of thread on this...(for instance
In-camera exposure compensation (EC) vs. EC during RAW conversion)

Cheers
Vincent