Digital cameras and ISO sensibility

[mat]

Hello,

When we talk of real films, I understand what ISO means, but what does it change on a digital camera ?

[thien]

The exact same thing. You gained on the speed and you loose on the grains, in the digital lingo: noise.

[nainconnu]

The result is the same, but ISO adjustments does not mean the same on digital cameras. On a digital camera, the sensor (CCD or CMOS) has a unique ISO setting. For example, on my Nikon D100, CCD sensibility is 185 ISO. Inceasing ISO on a digital camera boosts (increase gain) the data of the sensor perception. That's why you get noise with high ISO values. This noise does not look the same as on high ISO films but is interpreted similarly.

Hope I'm not too obscure!