Mirrorless Metering Explained
- Sonia - Chief Parrot
- Apr 18
- 5 min read
Updated: Apr 22
Metering for Bird Photography
Metering is the camera's way of reading light - and light is everything!
Many years ago I heard a saying 'you're not photographing an object, you're photographing light' and its really stuck with me.
It's a good little note to have at the back of your mind to remind you to pay close attention to the light and the way it is interacting with your subject.
Whether you're shooting a backlit egret or a robin in dappled shade, how your camera meters the scene directly affects your exposure. For intermediate photographers using mirrorless cameras, metering is not just a technical tool - it’s a creative ally!
What I love about mirrorless cameras is the ability to get lost in the moment, focus on what you can see through the viewfinder and not worry about constantly checking settings and needing to make complex adjustments. As a bird photographer, who's got the time for that??! 😁
Once you become familiar with fine tuning your exposure, and how your individual camera reacts to light, you slowly move into the wonderful space of shooting visually and intuitively, without fussing over settings - and this is when true creativity has the chance to unfold.
How Mirrorless Cameras Meter Light Differently
Unlike DSLRs, which rely on a separate metering sensor, mirrorless cameras use the main image sensor to measure light. That means what you see in your viewfinder or LCD screen is usually exactly what you’ll get in your final shot. Exposure changes update in real time, so you can make confident decisions before you even press the shutter.
General Metering Modes Explained Simply
Most mirrorless cameras offer three main metering modes. Here's when and why to use each:
Evaluative / Multi / Matrix Metering: The default mode for most situations. It looks at the entire frame and calculates a balanced exposure. Great for birds in evenly lit environments or when you're not dealing with extreme contrast.
Centre-Weighted Metering: Prioritises the centre of the frame more heavily than the edges. Handy when your bird is in the middle and you only want the background to slightly influence exposure.
Spot Metering: This mode only reads a small area—often linked to your focus point. Ideal for high-contrast scenes (e.g., a bright sky behind a dark bird). It helps ensure your subject, not the background, is correctly exposed.
Why Metering Feels Easier with Mirrorless
The magic of mirrorless? What you see is what you get! You don’t need to second-guess if your exposure is right - the EVF shows it live.
You may like to turn on highlight warnings (zebra stripes) or exposure histograms to catch blown-out whites or crushed blacks instantly.
I like to keep an eye on my histogram, especially if I'm in particularly tricky light where there is very bright and dark areas. Overcast days can also be difficult, especially when you can't see the sun's position. I also use 'ETTR' (expose to the right) , especially for high key shots, which is a favourite technique of mine (blog post upcoming on ETTR).
This really takes the pressure off, especially in fast-changing light conditions, so you can focus on composing the shot and not fiddling with your settings.
What Metering Does in Manual Mode
If you shoot full manual, you might be wondering why you need to pay attention to metering as the camera isn't setting the exposure. But it is still measuring the light and showing you where your current settings will land on the exposure scale.
Although the screen does a good job of showing you the result of your settings, it isn't perfect. There's a few instances where it can trip you up.
At night time or in very dull conditions, your screen automatically adjusts for the surrounding brightness - and so do your eyes!
This can mean under-or-overexposing quite significantly, which is where a quick glance at your light meter and histogram can help you fine tune.
I've been caught out on this one before! Shooting in near dark, it looked great on the screen, but at home - really underexposed to the point of not being able to recover the dark areas.
So while you’re in control, the camera's meter gives you feedback on whether your current shutter speed, aperture, and ISO will likely result in an underexposed, correctly exposed, or overexposed image based on the metering mode you’ve chosen.
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When to Ignore Your Light Meter
Even with great metering, your camera might misread certain scenes (like a white bird on snow). Use your exposure compensation dial (+/-) to tell the camera to brighten or darken the image, and watch the results in real time
Keep a close eye on highlights as it's the most common problem area - overblown whites cannot be recovered and can take away the finer details that make you image look really special!
📌 Cheat Sheet: Metering with Mirrorless – Quick Guide for Bird Photographers
Metering Mode | What It Does | Best For |
Evaluative / Matrix | Reads the whole frame for balanced exposure | Most general bird photography situations |
Centre-Weighted | Prioritises the centre area, ignores extreme edges | Birds in the centre, soft background balance |
Spot Metering | Reads only a small area (often your focus point) | High contrast scenes, tricky lighting |
💡 Pro Tips:
Watch the EVF/live screen closely for instant exposure feedback
Turn on highlight alerts and/or histograms
Use exposure compensation to adjust without leaving manual mode
Don’t be afraid to experiment—metering is flexible, not fixed!
I shoot with the OM-1, which has 5 metering modes - but as some of you know I'm a big fan of the KISS principle - Keep It Simple Sonia - so I rarely move from Digital Esp.
Instead, I keep an eye on my histogram and light meter, knowing when I need to slightly over or under expose for different creative scenarios.
Until you are familiar and confident with your camera's exposure, you may like to test out different metering modes and see how they work for you.
OM-1 Metering
Here's a breakdown of all 5 modes on the OM-1, you might like to experiment with each in different light conditions.
Digital ESP Metering (Evaluative / Matrix Metering)
This is the default mode and great for most situations. The camera analyses the entire frame, evaluating brightness, contrast, and subject position to give you a well-balanced exposure.
✅ Best for: General bird photography, especially in mixed or even lighting.
Centre-Weighted Averaging Metering
Gives priority to the brightness in the centre of the frame while still taking the rest of the scene into account.
✅ Best for: Birds in the centre of the frame, especially when lighting across the scene is fairly consistent.
Spot Metering
Measures light in a small area (about 2%) of the frame—either in the centre or linked to your focus point.
✅ Best for: Birds against bright or dark backgrounds where you want precise exposure control.
Spot Metering – Highlights
This mode ensures that the brightest parts of the metered area (like white feathers or sunlight hitting the bird) are exposed correctly to avoid blown-out highlights.
✅ Best for: White or pale birds in direct light, or scenes with intense highlights.
Spot Metering – Shadows
Exposes for the darkest parts of the metered area, helping you retain detail in shaded or low-light conditions.
✅ Best for: Dark birds in shadow or low-contrast environments where you want to avoid losing detail in black feathers.
Have you used different metering modes? Do you find it helps you judge exposure better? Let me know in the comments!
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