ISO

ISO has different meanings in film cameras and digital photography.

• Also known as film speed
• ISO always comes at the cost of details, sharpness and dynamic range

Film Photography

• ISO refers to film sensitivity in film cameras
• Higher ISO - more sensitive to light
• Film photography has grain, in the highlights

Digital Photography

• ISO in digital photography refers to applied gain
• Gain is applied after recording raw data
• Digital photography has noise, in the shadows

ISO Response Curves of Digital and Film Cameras

Related:

• Reciprocity
• Reciprocity Failure (in Film)