Metering Modes: Master Your Exposure

 The key to correct exposure is learning how to use the meter in your camera, but there are so many modes that it can be difficult to work out which one to use. Depending on your camera you may see options for spot metering, centre weighted, evaluative, matrix, etc. This guide will help you determine which mode is most suitable for different photo opportunities.

Understanding Metering

At its heart, metering is how your camera determines the correct exposure based on the light in your scene. It's a built-in light meter's best guess at what settings (aperture, shutter speed, and ISO) will give you a well-exposed shot. Different metering modes refine how this light is measured and can be the key to capturing images just as you envision them.

1. Spot Metering: The laser targeted option

Spot metering is the sniper of metering modes – precise, focused, and uncompromising. It measures light from a very small area (typically 1-5% of the viewfinder) at the centre of your frame. This mode is ideal when you have a specific subject you wish to expose correctly, ignoring the rest of the scene. It’s perfect for challenging lighting conditions, such as a backlit subject or scenes with significant contrast such as silhouettes.

Ideal For: Isolating subjects in challenging light. Think photographing a bird against a bright sky or capturing the details of the moon at night.

Limitation: Spot metering requires precision in your aim. Misplacing the metering point by even a small margin can lead to incorrect exposure, especially in mixed lighting conditions.

Real-World Scenario: Spot metering is perfect for shooting under a spotlight in a concert, where focusing on the performer’s face ensures they're well-lit against a darker audience. However, it’s less ideal in landscapes where the lighting is more uniform and you risk under or over exposing vast areas of your scene.

By taking a spot meter reading from the sky it's easy to create silhouettes like this.

2. Centre-Weighted Metering: The Balanced Approach

Centre-weighted metering takes a broader view than spot metering, focusing on the central area of your frame but also taking into account the rest of the scene to a lesser extent. It’s like having a balanced diet; it ensures the middle gets the most attention but doesn’t completely ignore the sides. Priority is given to the middle 60-80% of the frame, with a gradual decrease in sensitivity towards the edges.

Ideal For: Portraits and scenes where the subject is central. It's great for ensuring your subject is exposed correctly, with a gentle fall-off towards the edges.

Limitation: In scenes where important details or subjects are off-centre, centre-weighted metering may not provide the best exposure, as it prioritises the centre of the frame.

Real-World Scenario: Perfect for a classic portrait where your subject is in the middle of the frame against a complex backdrop. However, if you’re capturing a street scene with key subjects located at the frame's edges, this mode might overlook them, focusing exposure on the less important central area.

With a centrally positioned subject the "Centre Weighted" metering option is a great choice.

3. Evaluative/Matrix Metering: The All-Rounder

Evaluative or Matrix metering is the Swiss Army knife of metering modes, adept and ready for almost any scene. This mode evaluates the entire frame, using complex algorithms to determine the best exposure. It often prioritises the focus point, making it incredibly versatile for general photography. It’s your go-to for any situation where you want the camera to make an educated guess for a well-balanced shot. It’s especially useful in evenly lit conditions or when you're moving quickly and don’t have time to fiddle with settings.

Different camera brands have their own terminology for Evaluative metering, which might seem confusing at first. Canon and Sigma refer to it as Evaluative Metering. Nikon opts for the term Matrix Metering, Sony and Pentax go with Multi-Segment Metering whilst Fujifilm simplifies it to Multi Metering, and Olympus brings a digital edge with Digital ESP Metering. Regardless of the name, the fundamental concept remains the same: assessing the entire scene to make a balanced exposure decision.

Ideal For: General use across a variety of conditions. This mode assesses the entire frame, making it suitable for scenes with even lighting or when you’re on the move and need reliable exposure decisions made for you.

Limitation: In highly contrasted or backlit situations, evaluative metering might strive for an average exposure, potentially underexposing foreground subjects or overexposing skies.

Real-World Scenario: Shooting a landscape on a bright day, evaluative metering can balance sky and land beautifully. But, in a scenario where the sun is directly behind your subject, it might struggle to expose the subject correctly without manual adjustments or switching to a more focused metering mode.

Matrix/Evaluative metering which analyses the whole scene is perfect for landscapes such as this.

Mastering Metering: Practical Tips

•  Experiment: The best way to understand the impact of different metering modes is through trial and error. Take the same scene using all three modes to see how they alter your image.
•  Know Your Scene: Assess your lighting and subject. If your subject is small and in complex lighting, spot might be best. For larger, centrally located subjects, consider centre-weighted. And for quick, versatile shooting, evaluative is your friend.
•  Check Your Histogram: The histogram is a fantastic tool to evaluate your exposure post-capture. If you're consistently getting under or overexposed shots, your metering mode might need a switch. (see our blog post and video on how to use the histogram)
•  Custom Settings: Some cameras allow you to tweak how sensitive these metering modes are. Dive into your camera’s menu to see if you can fine-tune these settings to better suit your style.

Tweaks to get perfect results: Exposure Compensation and Bracketing

Understanding the technicalities of metering modes is one thing, but mastering the use of exposure compensation and bracketing with these modes can improve your results further:

•  Exposure Compensation: Allows for manual adjustment of the camera's exposure settings, essential when dealing with tricky lighting conditions. It's a quick fix to override metering decisions made by the camera.
•  Bracketing: Automatically takes several shots at different exposures (usually one at the metered value, one underexposed, and one overexposed), ensuring that at least one photo is perfectly exposed. Works excellently in high contrast or unpredictable lighting.

Practice is key

Grasping the nuances of your camera’s metering modes is a journey of discovery as each manufacturer has their own unique set of algorithms that determine the “correct” exposure. Regardless of brand, whether you're isolating a subject with spot metering, seeking balance with centre-weighted, or relying on the adaptability of evaluative metering, each mode offers unique advantages that, when mastered, can significantly enhance your photographic repertoire. So next time you're out with your camera, take a moment to experiment with each mode (your camera may have other modes that are specific to the brand). With practice and patience, you'll learn which metering modes work best for your type of photography and you’ll soon become adept at switching between them as needed. Remember, in photography, every little adjustment can lead to remarkable results. Happy shooting!