iso noise

Hey, I was reading my 20d manual....I know weird, who does that!. footnote at bottom of page 49, talkin about higher iso speeds and ambient tempertures will have more noise. I was wondering what higher temps they were referring to? I did not know this, how is temp related to iso?
gary

The temperature is color, as set to the Kelvin scale. It affects white blalnce

Sorry Southswede, but in this context color temperature/white ballance is not what they're talking about.

What they mean is if the air temperature is high you'll get more noise on your picture. My best guess is because when the sensor is warmer there are more things flying around inside it on the molecular scale, so you get more noise. It's called thermal noise, google probably can give you better information than I can about this.

I think in this case the manual is referring to actual ambient temperature. The sensor noise is dependent on the temperature at which it operates and will be worse (easier to see)at higher ISO settings. In other words, the noise will be higher on a hot day then a cold day. Dennis

thanks for the info... I guess this would mean a very hot day...like around 90*
Maybe we'll have to ask canon for a build in heat fan like on cpu's
gary

Try not to leave your camera in a hot place like the inside of your car, etc.