Understanding Light in Photography. Part One: Intensity

Summary

This video script introduces a new series of lighting tutorials, emphasizing the importance of understanding light properties before using devices like flashes. The host covers the four key qualities of light: intensity, color, direction, and quality. Demonstrations using a desk lamp and an LED light illustrate how light intensity affects exposure, and the inverse square law is explained to show how distance impacts light intensity. Practical examples and a quiz are provided to help viewers grasp these concepts, with the goal of improving their photography skills.

Takeaways

• 📚 The video is part of a new series on lighting tutorials, focusing initially on understanding the properties of light before using specific devices like flashes.
• 🔆 The four main qualities of light discussed are intensity, color, direction, and quality.
• 💡 Intensity of light refers to how much light is hitting the subject and can be adjusted by the power of the light source or the distance between the light and the subject.
• 🔄 Understanding 'stops' in photography is crucial, as they measure changes in light intensity and camera settings, doubling or halving the light with each stop.
• 🔦 Different light sources have different power levels, and 'full power' is relative to the specific light being used.
• 📐 The inverse square law explains how light intensity changes with the distance from the light source, with exposure changing in stops as the distance is halved.
• 📷 Practical application of the inverse square law includes adjusting camera settings or light power when changing the distance to subjects or including more subjects in the frame.
• 👥 When lighting a group, the inverse square law can affect exposure unevenly, with those closer to the light receiving more light, causing a need for adjustments.
• 🌟 Fall-off describes how light decreases rapidly when the light source is close, affecting the evenness of exposure in group shots.
• 🔄 To evenly expose a group, moving the light source further away and adjusting its power can help, as the light becomes more even as it spreads out.
• 🎥 The presenter emphasizes the importance of understanding these lighting principles for practical photography scenarios, such as parties or group photos.

Q & A

What is the main focus of the video series introduced in the script?

The main focus of the video series is to teach lighting tutorials, starting with the understanding of the properties of light before moving on to the use of specific lighting devices like flashes.

What are the four qualities of light that the video series will cover?

The four qualities of light to be covered are intensity, color, direction, and quality of light.

Why is it important to understand the properties of light before using a flash?

Understanding the properties of light is important because it provides a foundational knowledge that helps in effectively using a flash and achieving the desired lighting effects in photography.

What does the term 'intensity of light' refer to in the context of the video?

The intensity of light refers to the amount of light hitting the subject, which can be adjusted by the power of the light source or the distance between the light source and the subject.

How are changes in light intensity measured in photography?

Changes in light intensity are measured in 'stops'. Doubling or halving the light is considered a one-stop change.

What is the inverse square law and how does it relate to photography?

The inverse square law states that the intensity of light is inversely proportional to the square of the distance from the light source. In photography, it helps in understanding how changing the distance between the light source and the subject affects the exposure.

How does the distance between the light source and the subject affect the exposure in photography?

The closer the light source is to the subject, the brighter the subject will be. Conversely, moving the light source further away will result in a dimmer exposure. This relationship is governed by the inverse square law.

What is 'fall-off' in the context of lighting for photography?

Fall-off refers to the rapid decrease in light intensity as the distance from the light source increases, resulting in a less even exposure, especially noticeable when the light source is very close to the subject.

How can one evenly expose a group of people in a photograph using lighting?

To evenly expose a group, one can move the light source further back and adjust its height as needed, or adjust the flash power and camera settings to compensate for the light fall-off.

What is the practical application of understanding the inverse square law when taking a group photo at a party?

Understanding the inverse square law allows a photographer to adjust their lighting and camera settings appropriately when the number of subjects in the frame changes, ensuring even exposure for all subjects regardless of their distance from the light source.

How can changing the camera settings help maintain the same exposure when the light source is moved further away?

By adjusting settings such as ISO or aperture, a photographer can compensate for the reduced light intensity when the light source is moved further away, thus maintaining the same exposure level.