Edwin Yang
The Simple Way to Learn Exposure Triangle
Updated: Dec 20, 2022
I quickly write this article after receiving an interesting question on instagram. For me personally, this is essential for starting doing photography. Don't be intimidated by the phrase, it's quite easy to be understood and it will get better the more you implement it on your daily photoshoot.

Obviously, since they call it triangle, these are the three elements affecting the exposure of your photos:
Aperture
Shutter speed
ISO
Aperture
Exposure: The smaller the aperture number (i.e f/1.4), the more light captured by the camera.

Depth of field: the smaller the aperture number, the more bokeh your photos will be.

Shutter speed
As easy as how quick your camera open and close to capture the photos.
Exposure: The slower the shutter speed, the brighter the photos will be.

Motion: The quicker the shutter speed, the more sharp and defined the photos will be, and in contrary, using the slow shutter speed to moving objects will resulting the image look blurred.

ISO
Exposure: the bigger the ISO number, the brighter the photos will be.

Grain: the bigger the ISO number, more noise will be captured by the camera as the camera tries artificially to brighter the image, thus the noise.

How to balance
There's no exact way to tell which is correct and which is not. By default, I left my camera with this setting:
Aperture: f/4.0
Shutter speed: 1/250
ISO: 200
But that's not set on stone. Let's bring some real life case to the table and break it down.
For example, I'm about to shoot this table setup photo with a lot of food spreading on it.

Since it's outdoor, I don't have to worry about lack of light.
Since it's not a moving object, I also don't have to worry about playing with shutter speed.
What I need to make sure is, all the objects are well captured without leaving some parts blurred.
So, the first priority is the Aperture. If you forget the theory, click here to go back. I set the Aperture to f/5.6.
From there I can balance out the light by playing with the rest (ISO and shutter speed).
Let's use another example. A picture of me pouring coffee to the glass.

Aesthetically speaking, the best output is, I could capture every single drip of the coffee.
So, my priority here is the shutter speed. Click here to revisit the theory. I set the SS to 1/1000
With me bringing the shutter speed that low, naturally the whole photos will get dark. This is when we will see what's next to compensate the dark between ISO and Aperture.
If you notice, the laptop still looked sharp, that's because I use f/5.6. In this case, I crank up the ISO to 1600, because I don't mind a little bit of noise.
If you want less noise and don't mind if the laptop behind looked more blur, you can use lower aperture (e.g. f/2.8), so you can still use ISO 800 or maybe less.
Recap
Below is the cheat sheet so for starter you know what to do with all those number in a glance.
