ISO, Shutter Speed and F-stop explained as best I can
For a more intermediate explainer check out my blog
ISO, Shutter Speed and Aperture are the holy trinity of camera inputs. Understanding them is the number one thing you can do to help your photography that doesn’t involve interpersonal skills.
WHat they do
ISO - The sensitivity of film or a digital camera sensor.
Shutter Speed - How fast light is allowed to pass through a camera on its way to the film or sensor.
Aperture - The opening of a lens that will allow light to hit the film or sensor.
In this studio session I wanted to emphasize grain so I shot on 400 speed film and pushed the film using natural light instead of studio lights.
How they work
Shutter Speed and ISO can be explained well with old analogies I like about water.
Shutter speed is like the valve on a water spigot. If you open it quickly and close it quickly relatively little water will come out compared to if you left it open. The same thing is essentially happening with light pouring into your camera.
The mirror on this DSLR camera moves out of the way and the curtain shutter opens and closes to allow light to hit the sensor.
Aperture on the other hand correlates with the diameter of the hose or pipe the water is coming from. A drain pipe will let much more water through it than a garden hose.
ISO can better be explained like audio or music when you get more volume and can hear music better as you turn up the gain on a stereo, but noise is generated that may be unpleasant to hear. Adorama has a great breakdown here. And as for film, Richard Photo Lab in California explains it this way, “The higher a film stock's ISO is, the bigger the silver crystals are. That means a higher speed film will have more visible grain, while a slower speed film will have a finer grain.”
200 ISO Kodak ColorPlus