A light meter, also know as an incident meter, is a handheld device that helps to determine the light falling on a specific subject.

A light meter reads light falling on a subject and helps you know the accurate speed and aperture required to capture the exposure effectively.

Nowadays, a light meter is a pretty handy thing to carry in order to get your light right when filming a scene. It helps you to get your shooting into perfect parameters.

Each new camera has a built-in light meter and that makes things a little easier. But that isn’t going to help you out with filming a professional scene, where you’re dealing with multiple types of light.

A light meter has a great impact on filmmaking and photography. Let’s take a dive into light meters and everything you need to know about using your light meter.

Light Meters – What You Need To Know

First, you need to understand the three basic aspects of a light meter:

  • ISO,
  • Aperture or f/stop, and
  • Shutter speed.

These parameters allow a light meter to accurately define what would be the most perfect shutter speed and f/stop to use for a given subject.

The intensity of light in a scene is measure by the light meter and it provides exposure information. To take a light meter reading you would measure from the content’s point of view back to the camera.

It is said that the light is the most important thing in creating a fantastic scene and it can be a very tricky thing to grab control of light if you don’t know what you’re doing.

Of course, with time, an experienced cinematographer will learn to sculpt light. But even veteran directors of photography use light meters.

how to use light meter

A light meter will be a major help in determining the correct exposure and lens choice for a particular scene. And, yeah, your camera is a great aid in sculpting light to suit you, but experienced filmmakers will use the full range of tools available to them.

With your camera, you obviously have the built-in waveforms, histogram, zebra monitors with a variety of scopes, and more. But using the might meter is extremely easy for determining the right exposure to get the lighting set up in a certain scene.

A light meter will help you take away all of the guesswork, especially when shooting a professional narrative film.

At first, you’ll need a little practice to start with learning the various readings a light meter (or incident meter) gives you.

From there, you will need to set the aperture according to the exposure of the image. This will help you with positioning your lights and how to angle the actors appropriately to be lit in the best way possible.

Exposure

The first thing you need to understand about these variables is if you start by setting your camera back to its most basic functions: shutter speed, ISO, aperture, etc.

Exposure will define how light or dark an image will be, and this is a key component of what a light meter tells you about your scene.

how to use light meter

Step 1: Set Your ISO

Setting your ISO is the very first thing. The ISO which has been set on your camera must be set on your meters as well.

Also, check that the meter is set to daylight. Many people think that ISO is a tool to tell the exposure. It only affects the manner that it changes the sensitivity of the sensor to light.

It does not change the amount of light that is exposed. Only shutter speed has the ability to change it fully.

If the ISO is dialed it can completely give information to the light meter which will give proper exposure at the same time. The ISO finds your camera’s sensitivity to light. The higher your ISO is the more sensitive it is to light.

The lower the ISO is the clearer pictures will be – they’ll have much less grain. The higher the ISO number, the more graininess you’ll have in your image.

how to use light meter

Step 2: Take The Reading

Hold your meter in front of your subject. And check to see where the light is coming from. First, you need to find the light then carefully place your meter in front of your subject, not to the camera.

Now press the metering button to measure the light in the scene. Set the reading in your camera’s exposure setting. You must set your camera in manual mode.

There are many people who ask why shouldn’t you use your camera meter instead of buying an expensive handheld meter. Your handheld meter will take a more accurate reading than your camera meter.

The problem is your camera meter takes the reflected light and then it takes a reading according to the amounts of mid-tones. The percentage of grey will, therefore, change in every shot.

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Step 3: Aperture

Inside your light meter, there’s a component called an iris. It is roughly circular and is comparable to the aperture in your camera.

The larger the aperture will be the more light is let through it, the smaller the aperture the less light is let through. It varies in size.

The aperture is listed as a fraction. The system of the aperture will be hard to understand for a beginner if he/she did not learn the maths behind it. The smaller the number, the larger the aperture will be.

For example, 2.8 is a large number and 22 is small. These numbers are also known as f stops or f numbers. And sometimes written down as f/5.6, f/2.8, f/16, f/4, etc.

  • Set your camera in manual mode and dial the aperture of your choice.
  • Select your camera’s program mode and then shift the aperture.

Step 4: Shutter Speed

If you open the shutter, light will travel and hit the sensor. The more the shutter is open, the more light will hit the sensor. And, likewise, the more you close the sensor, the less light will make it to the sensor.

A slow shutter speed will let light in for longer. And the fast one would let less light in. It is measured in seconds.

  • Press on the control button,
  • Select your shutter speed,
  • Now finally Press to shoot your scene.

I hope the above has brought some knowledge and clarity to your use of the light meter in filmmaking.

We hope this article on how to use a light meter has been helpful to you. What are your experiences with using a light meter? Let us know in the comments below.