The Exposure Contraption

“Exposure” is one of those photography fundamentals that sounds simple, until you try to actually explain it. Most photography students are first introduced to the exposure triangle, a diagram showing ISO, shutter speed, and aperture at each corner. The idea is that changing one side affects the others, and together they determine how bright or dark your photo turns out.

It's a tidy little graphic, but I've always found it unhelpful in practice. A triangle doesn't move, tilt, or react. It made sense only after I already understood exposure. Worse, it completely ignores one of the most important parts of the process: the amount of light in the scene to begin with.

Enter the Exposure Contraption

Instead of a triangle, this simulation turns exposure into a physical scale, something that literally balances light. On one side sits the light itself, represented by a glowing source that changes from bright daylight to dim indoor light. Next to it is ISO, which acts like a "light multiplier," amplifying whatever light is available. On the other side are aperture and shutter speed, both of which control how much of that light actually reaches the camera's sensor.

When both sides of the scale are balanced, you get a properly exposed image. When the scale tips, you're either letting in too much light (overexposure) or not enough (underexposure). Suddenly, the abstract relationship between these settings becomes visible, even tangible. You can see how a slower shutter speed or a wider aperture can "lift" a dim scene back into balance, or how bright sunlight requires you to close down the aperture or speed up the shutter to keep things even.

What I love most about the Exposure Contraption is that it gives light itself a spot in the exposure equation. The exposure triangle assumes that light is constant, when in reality it’s the entire reason these settings exist. You don't adjust ISO, aperture, and shutter speed in a vacuum, you adjust them in response to light.

By visualizing exposure as a scale to balance instead of a static shape, the Exposure Contraption helps bridge that gap. It shows that getting a good exposure isn't about memorizing rules, but about feeling the balance between available light and your camera’s controls. And when that balance clicks in your mind, you stop guessing and start predicting how each setting will behave before you even take the shot.

The triangle explains exposure in theory, but the Exposure Contraption shows it in motion. And I think for most learners, seeing that balance swing into place makes the concept finally make sense. I hope it gives you a different and helpful perspective on the very important topic of exposure!