Light Metering Basics: Using an Incident Meter

Summary

In this video, the presenter introduces incident metering, a fundamental technique in photography and videography for measuring light. The video explains how the lumisphere, an unbiased light meter, works by measuring the light falling onto its dome. The presenter demonstrates how to use the meter to set lighting ratios, crucial for creating different lighting effects. They adjust key and fill lights to achieve a two-to-one ratio, showcasing the process with a model. The video also covers the concept of f-stops, explaining how they quantify light and are used to calculate lighting ratios. The presenter's practical examples and tips make incident metering accessible, even for those unfamiliar with the concept.

Takeaways

• 🌟 Incident metering is a basic form of light metering that measures the light falling onto a white dome called a lumisphere.
• 🔍 The incident meter is unbiased as it does not consider reflectance or the color of the subject, only the amount of light falling on the dome.
• 📏 The meter provides an f-stop reading that indicates the amount of light available for a given scene.
• 💡 Adjusting the light source's intensity can change the f-stop reading, allowing for precise control over lighting ratios.
• 🎥 Lighting ratios are crucial in cinematography and describe how much brighter or darker one light source is compared to another.
• 🔧 The incident meter can be used to set up lighting ratios by measuring the key light and adjusting the fill light accordingly.
• 📉 When retracting the lumisphere, it can isolate a single light source, allowing for more accurate readings of that specific light.
• 📸 The script discusses butterfly lighting, a technique that creates a subtle shadow under the nose, often used for beauty shots.
• 📈 Understanding f-stops is essential for quantifying light and calculating lighting ratios; each f-stop represents a doubling or halving of light.
• 🤔 Memorizing the f-stop scale can be aided by recognizing that each stop is either double or half the previous amount of light.
• 🎬 The incident meter is a practical tool for filmmakers to set lighting ratios and ensure consistent lighting across different shots.

Q & A

What is incident metering?

Incident metering is a method of measuring light that involves using a device, like a lumisphere, to measure the amount of light falling onto its dome. It is unbiased because it doesn't care about the subject's reflectance or color; it only measures the light that reaches the meter.

What is a lumisphere?

A lumisphere is a small white dome used in incident light meters to measure the light falling onto it. It is designed to provide an unbiased measurement of light.

How does incident metering help in setting lighting ratios?

Incident metering helps in setting lighting ratios by allowing the user to measure the amount of light falling on the subject and then adjust the light sources to achieve the desired ratio. For example, if the key light measures at f/2.8 and the fill light at f/2, that's a 2:1 ratio, with the key light being twice as bright as the fill.

What is an f-stop and how does it relate to light measurement?

An f-stop is a unit used in photography to describe the amount of light that reaches the camera sensor. Each f-stop represents a halving or doubling of light, with a lower f-number allowing more light and a higher f-number allowing less light.

How can you remember the relationship between f-stops and the amount of light?

The relationship between f-stops and light can be remembered by knowing that each stop represents a halving or doubling of light. For example, going from f/2 to f/4 halves the light, while going from f/4 to f/2 doubles it. The scale can be memorized by starting with f/1 and f/1.4 and then doubling the previous number to get the next f-stop.

What is the difference between a key light and a fill light?

The key light is the primary light source that defines the subject's appearance and establishes the overall lighting mood. The fill light is a secondary light source used to soften shadows created by the key light, providing more even lighting.

What is a lighting ratio and why is it important?

A lighting ratio is the relative measurement of the brightness between the key light and the fill light. It is important because it helps to create depth and dimension in a scene, as well as to set the mood and style of the lighting.

How can you adjust the incident meter to measure a single light source?

To measure a single light source with an incident meter, you can retract the dome and cover the head of the meter, then point it towards the light source you want to measure. This isolates the light from other sources.

What is butterfly lighting and how is it achieved?

Butterfly lighting, also known as Paramount lighting, is a style where the key light is positioned high and slightly in front of the subject, casting a shadow under the nose that resembles the outline of a butterfly. It is typically achieved with a soft light source and is flattering as it creates a soft shadow and even lighting.

How can you use incident metering to create menacing or dramatic lighting?

To create menacing or dramatic lighting with incident metering, you can turn off the key light and measure the light levels with the fill light only. This can create a darker, more dramatic scene by reducing the overall light and increasing the contrast.

What is the significance of the number 5 in the context of stops and light measurement?

In the context of stops and light measurement, a difference of 5 stops means that one light source is either 32 times brighter or 32 times dimmer than another. This is because each stop represents a doubling or halving of light, and 2 raised to the power of 5 equals 32.