Camera Metering: How the Heck it Works



Welcome to a beginner’s guide on camera metering, and this is going to be another short one. Ever wonder how modern cameras automatically “know” how to take photos that are not too bright or too dark? The answer will be, through a series of built-in (light) metering sensors.

But even with today’s technology, it is not perfect, and you will sometimes get photos that are too bright or dark. This guide will help you understand metering, and how to tweak it a little to get better photos.




Before we start, this is one word that you have to know in the world of photography – Exposure. You might have heard of this many times already, but what the heck is this exposure that photographers are talking about?

Well, in the simple terms, it means exposing the camera’s electronic light sensor to light when we take a photo. That easy. The next thing you need to know about exposure is –

  • If the camera does not get enough light, the photo will end up too dark. We call this under-exposed.
  • The other way round, if the camera gets too much light, the photo will end up too bright. We call this over-exposed.
  • We usually aim for “just right”, but know that there are times where photographers will deliberately over or under expose to create drama.




In the days long past, there is no such thing as “automatic”. Photographers have to use a bunch of scientific equipment to calculate the amount of light, then do estimations on the camera settings in order to get the correct exposures.

Today, we thankfully have better technology. No longer do we have to walk around like Einstein, nor do we have to do crazy calculations. Because everything is built into the camera, and all the calculations are done automatically in the camera. But there are still times when the automatic calculations will be off. 2 common examples :

How did those happen? In a nutshell, the difference between the brightest and darkest spot is too much.

  • The sky is too bright while the ground is dark. Modern cameras are probably smart enough to know that it is a landscape photo, and try to “average” the exposure. While this does help a little, the sky will still be over-exposed (blown out white), because of technical limitations.
  • In the sparkler, modern cameras will probably try to adjust towards the brightness of the bright sparkler, resulting in a dark background instead.




So just how do we “fix” these? Personally, I will use a GND filter (see the previous guide on photography filters if you have missed it out) on the landscape, and put a light on the girl with the sparkler. But if you do not have any of these, and you do not know how to do manual camera settings, your next best bet is to play around with the metering modes.

Infographic – Metering Modes
  • Spot Metering: Uses a spot you selected as consideration for camera exposure settings.
  • Partial Metering: Similar to spot, but uses a larger area.
  • Center-weighted Metering: Uses the center of the frame as consideration.
  • Matrix / Evaluative Metering: Uses the entire frame as consideration.



So how do we use the different metering modes to get a better-exposed photo? Very simple, tweak around with a metering mode that works. For example :



This is something extra for you slightly advanced photo ninjas, and metering is not just for the purpose of shooting in automatic. If you look through the viewfinder, you will see those bars thing.

That is metering in action, and yes, the metering modes still apply. But in the case of manual settings, these bars will tell you if your current settings are over-exposed (bars on the plus side), or under-exposed (bars on the minus side). This will apply to the aperture, shutter, and program modes as well.



Here comes the end of yet another short lesson. Hope this has been a tiny step forward for you, and keep shooting! If you have question, please feel free to comment below. Happy shooting!


Previous Lesson: Auto Focus Next Lesson: Exposure Triangle


Leave a Comment