What is exposure?

We simplify image exposure as a definition of our image being too dark or too bright.An image contains two major components: the chrominance and the luminance.

The chrominance represents the colors and the luminance the brightness of an image.So Let’s just focus on the luminance part as it’s the defining factor for our exposure.

A film scene will always have something in the frame that is either completely white or completely black and a range of grey tones inbetween. This is what we call the total tonal range of our image.Imagine our tonal range as a scale that goes from black, 0% to white, 100%.What we want is to measure for a specific grey area in our image to be at exactly 18% grey.if we match this everything else will fall into place reproducing the image of our scene in camera as we perceive it in real life.Thus Acheiving overall correct exposure.

The exposure golden triangle

The exposure triangle explains the relationship between shutter speed, ISO and aperture. You are always trying to capture light in a sense, when creating your image. Whether you’re shooting old school film or with a mirrorless camera, or even your smartphone these three factors are at the center of every light capture, or what we now defined as exposure. Every time you try to take a picture a combination of these three key factors.


In very basic terms, ISO is simply a camera setting that will brighten or darken an image. It is how sensitive your sensor becomes to light. Higher ISO number more sensitive, Lower ISO numbers less sensitive to light.


Aperture can be defined as the opening in a lens through which light passes to enter the camera.


Shutter speed is the length of time camera shutter is open, exposing light onto the camera sensor

On set tools to help you calibrate your exposure

Light Meter

A light meter is a device used to measure the amount of light.A light meter is a tool that helps you navigate between your camera settings by measuring the strenght of the light on set.

Grey Card

A gray card is a middle gray reference, typically used together with a reflective light meter, as a way to produce consistent image exposure and/or color in video production, film and photography. A gray card is a flat object of a neutral gray color that derives from a flat reflectance spectrum.

In Camera tools

Exposure Meter

Exposure meter, also called light meter, is an in camera photographic auxiliary device that measures the intensity of light and indicates proper exposure (i.e., the combination of aperture and shutter speed) for film or image sensors of a specific sensitivity


A histogram is a graph showing the distribution of light in an image. ... A histogram shows you the number of pixels of each brightness in your image. The scale along the bottom of the histogram goes from left to right, from 0% brightness (black) to 100% brightness (white).