UNDERSTANDING YOUR LIGHT METER IN YOUR CAMERA:
Now, I know you thought that maybe I had covered everything you should know about your camera, but there is a couple of things still I want to cover before we get to the fun part of composition and learning how to become an artist and apply all the things you have learned so far.
You live in a day where your camera is designed with many great things to help you take the most incredible photos without much effort on your part. But, I hope that one thing you will discover through all these training blogs, and training information thrown at you at this time, is that if you totally rely on your camera to give you a perfect picture every time, you will certainly be disappointed. I remember when I worked in the “photo store” and people would come into my store seeking answers as to why their camera did not give them the perfect photo. And I told them their camera was working perfect, and it was the operator not knowing everything about what their camera was doing. So, here is one more thing to learn about so that you can have all the tools to make your photos perfect.
THE LIGHT METER:
First of all, to make sure you understand how light meters work, all camera manufactures have come up with a reference point in which to make all the exposures perfect. The perfect color balance. That calibration color is what they call: 18% grey.
If you go into a camera store, not a cheap store like Walmart or Target (sorry, not trying to be mean here), but someplace that really knows photography, and ask to see an 18% grey card, they will know what you are talking about. The way to get a perfect exposure every time is for you to take a light meter reading with the light that you have, with the grey card.

Once you have a light meter reading, using the grey card, then you take the photo, and you will have a perfectly exposed photo. You know you have to do this in manual mode to do this. If you take it in automatic mode, then it won’t work. Unless you have some way to lock the exposure, once you have taken the exposure reading. You will be amazed at how perfect your pictures are using this concept. You will often see professional photographers still use a grey card to this day. They want their photos to be perfect. No second guesses.
In most DSLR cameras you have 2, 3, maybe 4 different types of light meters available to use. Let’s take a look at the different types of light meter modes that you have, so you can understand why, and what you would use them for.
THE MATRIX OR EVALUATIVE or MULTI-POINT METERING SYSTEM:
Some camera manufactures will call it their “matrix” metering system. Others may call it their “evaluative” metering system, while others may call it their “multi-point” metering system. In general they all kind of work the same, and they are all very brilliant. I marvel each time I have my camera set on this especially when taking pictures of a group of people, because all those little dots are each their own little light meter taking a light meter reading, evaluating the reading, feeding that information into the computer of the camera, and setting the cameras automatic mode to the perfect exposure of the reading between all the different readings it got from all those different points. In my camera, you will see little lights, light up on each person’s face, so you know it senses what it thinks is the subject. But, as you will notice in the two photos above, that it is not perfect, as neither one of those photos turned out right. On the left, who is that person? And on the right, who is that person? The meter took readings of all the points around the person, and thought that those points were as important as the subject. The camera does not know any better. And that is why you need to have a “spot Meter”.
THE SPOT METER:

That little red dot gives you an idea of just how much area the spot meter is taking the light meter reading. It is so precise that it will not even care about anything else around that area. Boom, it is that area, and nothing else. Is it always the perfect one? NO.
CENTER WEIGHTED MODE OR PARTIAL MODE:
Partial metering mode is somewhat like a spot meter, but just covers a larger area. I find it especially a good one to use with portraits:
Here, with center weighted metering, you would get a larger portion metered of the person without including so much of the background. I do not need to get just a spot meter reading of an eyeball, which is what you would get with a spot meter. A spot meter may be used more when contrast is so dynamic in your frame.
SO WHY USE MATRIX OR EVALUATIVE (MULTI-POINT METERING)?
Multi-point metering is everyone’s version of AI ( Artificial intelligence). This is the new world of smart cameras, and if you want my opinion of this type of metering, well, I find it amazing.
Imagine pointing your camera at a sunset, and the camera knows it is a sunset, and gives you the most perfect, beautiful sunset you have ever taken. No adjustments was needed on this photo above. That is shot on “evaluative metering”.
This photo was also taken with the metering system in the “evaluative metering” mode. Colors are rich, and exposure right on.

SO, WHEN TO KNOW WHICH TYPES OF METERING TO USE:
- WHAT IS THE MOST IMPORTANT SUBJECT IN YOUR PHOTO, AND MAKE SURE THAT IS WHAT IS PERFECTLY EXPOSED.
- IS YOUR ENTIRE FRAME AND ALL THE SUBJECT MATERIAL SEEM TO BE ABOUT THE SAME EXPOSURE (OR NO CONTRAST TO THE PICTURE)?
- REMEMBER CONTRAST PLAYS A BIG PART IN WHAT COMES OUT RIGHT IN YOUR EXPOSURE. WHAT DO YOU WANT EXPOSED CORRECTLY.
- ALL LIGHT METERS, REGARDLESS OF TYPE, THINKS THAT IT HAS EQUAL GREY IN COLOR. IF YOUR SUBJECT IS LIGHT OR DARK, DON’T USE THAT AS A METER READING. REMEMBER YOUR CAMERA METER IS CALIBRATED TO 18% GREY.
- AND ALSO REMEMBER THAT TO GET GOOD WITH METERING AND LEARNING THE DIFFERENT STYLES WILL TAKE SOME PRACTICE. DON’T BE DISCOURAGED IF THEY DON’T COME OUT. IF YOU ARE USING A DIGITAL CAMERA, AND IT DOESN’T COME OUT, DELETE IT AND TRY AGAIN USING A DIFFERENT TYPE OF METERING SYSTEM.
Hope this has helped you to understand light meters and how the camera’s metering system works. Seems complicated, but, I hope I explained it in a way you will understand it. There is a place for questions or comments at the bottom of this blog if you need further information.