shutter speed noise

[mandab99]

I have done a bit of experimenting today and found that noise not only comes from using a higher ISO but from using slower shutter speeds too, is this why indoor photos produce more noise because slower shutter speeds are needed for correct exposure? I understand why a higher ISO produces noise but dont know why a slower shutter speed does so too???

[Wayne]

This is usually only an issue in long exposures, like several many seconds and more. It also depends on how your body handles long exposure NR, many DSLR bodies have a long exposure NR setting you can adjust or turn on/off. The noise is attributed to the heat generated in the sensor when it is active for longer periods.

[mandab99]

Yeah the series I took was between 5 and 25 seconds. Thanks for explaining further Wayne.