Intro. Exposure Triangle
Introduction to the Exposure Triangle
The Exposure Triangle is the three working elements of a developed film frame/digital image. These three components work together to capture light and document that data in a way that allows us to view the image in accurate color and brightness.
The first component is ISO. You can read the full write up of ISO here, but to break it down simply, the ISO is the film speed (or digital variation of film speed) and this is how sensitive the fim is to light. If it’s a low number it is less sensitive so 100-200 is slow, and least sensitive, you use this when there is A LOT of light, you need 100-200 ISO when shooting outdoors. AND Higher ISO when shooting indoors, the film is more sensitive to light so it will be properly exposed in lower lit scenarios. High ISO 800 indoor lighting, dark lighting even higher - digital cameras can often go up to 256,000 ISO. Traditional fim does not go anywhere near that high.
Low ISO More Light Needed = everything in photography is about balance
Higher ISO Less Light Needed = Indoors
The second component is shutter speed. Shutter speed is how fast your shutter opens and closes. You can read the full shutter speed write up here. The shutter is the thing that allows the light in! As you can see in the illustration above you need a slower shutter speed to let in more light and a quicker shutter speed to let in less light. 1/125 second is the lowest I like to go when photographing people in lower lit spaces. you’ll see it written as a fraction or as a complete number - the complete numbers are in seconds. 1/2500 would be if you’re outside in bright light.
the third is aperture. Aperture is how wide the lens opens to let light in. You can read the whole aperture write up here. Aperture uses f/stops to explain how wide the lens is opening. The terms are often used interchangeably. I shoot a lower number f/stop 1.8 indoors low light because the hole is bigger. I shoot 5.6 or as high as 11 outdoors because the hole is smaller and lets in less light. Oftentimes I think of the components as opposites because it’s about maintaining balance, Bigger hole needs less light bigger hole is smaller number. These things get confusing until you really understand them. so focus on one component at a time. Leave your shutter speed at a fixed number and iso at a fixed number and see what happens when you adjust just your aperture.
Lots of these aspects can be done with a cell phone camera now so you can still utilize this knowledge with a basic camera, you just have more control when shooting in manual mode on a DSLR or Mirrorless camera.