Canon Explains Exposure
It might seem counter-intuitive, but the more expensive your digital SLR camera is, the fewer automatic controls it offers. Once you get to a certain camera tier, such as a full-frame digital, you won’t find the same automatic modes that are essential in consumer-level models that cost less than $700. You’ll need to make some decisions about ISO, aperture, and shutter speed.
Canon has published a web tool, cleverly titled “Outside of Auto,” that explains and illustrates how changes to those settings will affect your final photograph.
Because these settings are inherent to all photography, they apply to any make of camera, such as Nikon and Sony, Holga and Leica, iPhone or Samsung. And yes this applies to film as well as digital.