exposure triangle


What is the exposure triangle?

The Exposure Triangle is one of the best-known concepts to “explain” how photography works. It can be found in books, on many websites, and even in the manuals of many camera manufacturers.

Unfortunately, it's also the biggest source of confusion in photography.

That’s the reason why we created this page. We want to show you alternatives to the Exposure Triangle that help you understand exposure better and faster.

Here is the better explanation


When photographers talk about exposure, they actually mean image brightness. An image can be:

under exposed

When the image is too dark.

well exposed

When the image brightness is perfect.

over exposed

When the image is too bright.


Exposure contains the word expose. So to understand, we have to ask ourselves two questions:

1. What is exposed?

That’s the sensor of our camera, or for film-photographers, the film.

2. What is it exposed to?

To the scene you want to photograph. So basically to more or less light, because the scene can be brighter or darker.

So light is the source of it all. Photography is Greek. Some people say it means painting with light, but it really means the light paints so the light is the artist and the source of our images.

Let me repeat that, because it is so important:


1. Scene Luminance

First and foremost, scene luminance, or light as you have learned above. It is the most important component of exposure because it is the source of our images.
Quite logically, the higher the light level in our scene is, the brighter the image will be.
For us humans that is sometimes hard to understand because our brain does a great job at presenting us pretty constant light levels.
In reality, the light level changes dramatically. A scene lit by the full moon is 100.000 times darker than a scene lit by the sun at noon. Or a scene in a regular gym when photographing your kids doing sports is 250 times darker than outdoors. In photography these varying light levels force us to make compromises.

2. Aperture

To get into the camera, the light that is reflected by the scene we want to photograph, passes through the lens. In that lens is a hole that is variable in size called aperture.
Again quite logically, the bigger the opening in the lens, the more light can enter the camera.
Compare that to a window with blinds. The more you close the blinds, the more light will be blocked and the darker the room will get. Analogical: the more you close the aperture, the less light will enter your camera, the darker your image will get.

3. Shutter Speed

After the light passes the aperture, it’s almost at it’s destination, the camera sensor. Before it can start exposing the sensor, it is blocked by a shutter.
To open it, we have to press the shutter button of our camera.
The amount of time the shutter is opened to expose the sensor to the light in the scene is called shutter speed. But the correct term would be exposure time.

With the closing of the shutter, exposure has ended!!!

Do you miss ISO?

ISO is the gain that is applied AFTER the shutter has closed and the sensor is not exposed to light any more. In fact it is a first step of image editing, because the RAW data the camera collected is being brightened by the cameras software.

So ISO is not a part of exposure, but rather very similar to what you would do in your editing software. And you wouldn’t call brightening your image in Lightroom, Luminar, or any other software part of exposure, would you?

where is the exposure triangle wrong?

That leads to massive confusion among beginner photographers, who think the camera settings are a magic mix, while in reality they are just a reaction to the amount of light we have available. When you understand that photography is all about light, everything else will be much easier to understand.

Now let me recommend learning how each camera setting affects your images.

Do you want to shoot images like these?

These images were all shot by me. My name is Wolf Amri, I’m a professional photographer and film maker.

On my youtube channel, I explain not only exposure, but everything else you need to know about photography. Explaining in a video is much easier than written because I can show you images, animations and examples on the way. So let me recommend watching my youtube beginner photography course.