Camera metering modes are an essential aspect of photography, helping photographers achieve proper exposure in their images by determining how the camera measures light and sets the appropriate combination of shutter speed, aperture, and ISO sensitivity.
Different metering modes are available to accommodate various lighting conditions and shooting scenarios. The concept of “18% gray” is closely tied to metering in photography. The idea behind it is that an average scene reflects about 18% of the light that falls on it, regardless of the scene’s actual brightness or color. This serves as a baseline for determining proper exposure. When a camera meters a scene, it’s attempting to calculate settings (shutter speed, aperture, ISO) that will result in the captured image’s average brightness being close to this 18% gray level.
- Matrix (Evaluative) Metering: This mode analyzes the entire scene and divides it into multiple zones. The camera then calculates the optimal exposure based on the brightness values in these zones. It’s a versatile mode suitable for a wide range of situations, as it considers various elements in the frame.
- Center-Weighted Average Metering: In this mode, the camera gives more emphasis to the central area of the frame while calculating exposure. It’s particularly useful for portraits and situations where the subject is centered and well-lit.
- Spot Metering: Spot metering measures the light intensity only in a small spot at the center of the frame (typically around 1-5% of the viewfinder area). This mode is great for situations where you want precise control over the exposure, such as when the subject is backlit or in high-contrast lighting conditions.
- Partial Metering: Similar to spot metering, but with a slightly larger area (around 10-15% of the viewfinder area) being measured for exposure. This mode is useful for capturing subjects against bright backgrounds.
- Highlight-Weighted Metering: This mode is designed to preserve highlight details in the image, making it suitable for high-contrast scenes where maintaining details in bright areas is crucial.
- Average (Standard) Metering: In this mode, the camera calculates the average light intensity from the entire scene, without giving any particular emphasis to specific areas. It’s a basic metering mode that can work well in even lighting conditions.
- Center-Only (Partial) Metering: This mode meters the center of the frame and ignores the rest. It’s useful when you want to expose a specific area while ignoring the surroundings.
- Backlit (or Exposure) Compensation: While not a metering mode per se, exposure compensation allows you to manually adjust the camera’s calculated exposure. This is useful when the metering mode might be misinterpreting the scene’s lighting, such as in strongly backlit situations.
In the early days of photography (the 1800s), the concept of exposure measurement was rudimentary. Photographers relied on trial and error to determine the appropriate exposure settings. Light-sensitive materials like collodion plates and early films had limited dynamic range, making precise exposure crucial. As photography advanced (1930s-1940s), early reflectance meters were introduced.
These handheld devices allowed photographers to measure the intensity of light reflecting off a subject. However, these meters were separate from cameras and required manual input of settings. In the mid-20th century (1950s-1960s), manufacturers started integrating exposure meters into cameras. These meters often used a selenium cell, which produced a current proportional to the amount of light falling on it.
These early built-in meters usually offered basic averaging of light and dark areas in the scene. In the 1960s and 1970s, center-weighted and spot-metering modes began to appear in more advanced cameras. These modes allowed photographers to measure light in specific areas of the frame, providing more control over exposure. Spot meters, for instance, were particularly useful for situations where precise metering was necessary, such as backlit subjects or high-contrast scenes.
As camera technology evolved, manufacturers introduced more sophisticated metering modes like matrix (evaluative) metering (1980s-1990s). Matrix metering divides the scene into multiple zones and evaluates the light intensity in each zone. This allowed cameras to take into account various elements in the frame, including subject distance, color, and composition, to determine exposure. With the rise of digital photography (2000s-present), metering technology became even more advanced. Digital cameras allowed for instant feedback on exposure settings, which in turn facilitated the development of more complex metering algorithms.
Highlight-weighted metering, for example, became feasible due to the processing power of digital cameras. Modern cameras often offer a variety of metering modes, each designed to handle different shooting conditions. These modes are backed by sophisticated algorithms that analyze the scene and calculate exposure settings accordingly.
Cameras might also offer exposure compensation and auto-exposure bracketing, further enhancing a photographer’s control over exposure. The history of metering modes showcases the continuous effort to provide photographers with tools that enable them to capture accurately exposed images in a variety of lighting situations.
As technology continues to advance, it’s likely that metering modes will continue to evolve to meet the demands of photographers seeking more creative control over their images.
When shooting HDR images, the two metering modes you will generally be using are either the Evaluative/Matrix (Scene-Based) Metering Mode or the Spot Metering Mode. However, choosing a metering mode really depends on your personal preference and your own workflow.
The Evaluative/Scene-Based Metering Mode is safest when shooting HDR images in Aperture Priority because your camera will balance everything out and find the median exposure based on the entire scene. When shooting HDR images, we generally have 3 different exposures: a dark exposure, a median exposure, and a bright exposure which will capture the details and dynamic range of the scene. The Evaluative/Scene-Based Metering Mode is a simpler option when first shooting HDR images, but is also great in the Manual Mode.
- Highlight-weighted metering is a camera metering mode that prioritizes retaining highlight details in a scene, particularly in high-contrast lighting conditions. Unlike traditional metering modes, which aim for overall balanced exposure, highlight-weighted metering calculates exposure settings to prevent overexposure in bright areas. This mode is particularly beneficial when capturing scenes with strong backlighting or scenes containing bright light sources. By preserving highlight details, photographers can maintain intricate textures and subtle tonal variations in the brightest parts of the image. [Back]
- Auto-exposure bracketing (AEB) is a photography technique where a camera automatically captures a series of images at varying exposure settings, typically including one correctly exposed image, an underexposed image, and an overexposed image. This technique is particularly useful in high-contrast scenes where achieving a balanced exposure for both shadows and highlights can be challenging. By capturing a range of exposures, photographers can later choose the best image or use post-processing software to blend the bracketed shots, resulting in a final image with a wider dynamic range. AEB is a valuable tool for landscape, architecture, and HDR (High Dynamic Range) photography. [Back]
- “DSLR Metering Modes Explained” https://livesnapcreate.com/dslr-metering-modes-explained/
- “What Are Metering Modes? A Practical Overview” https://www.slrlounge.com/in-camera-metering-modes-tutorial/
- “Understanding Metering and Metering Modes” (UPDATED ON APRIL 22, 2023) https://photographylife.com/understanding-metering-modes
- “Exposure Meters” http://www.earlyphotography.co.uk/site/meters.html
- Peterson, B. (2017). Understanding Auto Exposure Bracketing (AEB) for HDR Photography. Retrieved from https://www.digitalphotographyschool.com/understanding-auto-exposure-bracketing-aeb-for-hdr-photography