#3 DSLR Camera’s built in light meter

Part Three – Using your camera as a light meter

Did you know that your SLR camera has a built in light meter? This is what helps you when you have it set on automatic, but you can also use it when you put it onto manual. It measures the light coming into the camera through your lens. The scale at the bottom of your view finder can be used to establish the right exposure for your shot.

Transcript of Video

“Put your camera on “Manual”
Before we go any further I want you to take your camera off “Automatic” put it on “Manual”.

This will help you to learn and get much more out of your photography.

You can then start playing with different effects that are not possible when you’re camera is set on “Automatic”.

By having your camera on “Manual” you will still be able to use the light meter that is built into your camera. But instead of your camera automatically dialing in the controls that set your exposure you will have to manually dial them in.

This will help you learn the settings and memorise them to better effect.

using your light meter on manual
In it’s most basic form your camera is a light box that captures light through the lens and exposes an image on the sensor at the back of the camera.

When you have your camera set on automatic what effectively is happening is your camera uses the built in light meter that looks at whatever you point your camera at and evaluates the amount of light that’s bouncing back into through the lens and works out what the correct shutter, aperture and ISO should be so that it gets an image that’s not too light or too dark.

Now when you put your camera on “Manual” you can still utilise you’re cameras built in light meter. Here’s how…

When you actually look through the view finder you’ll see a little scale at the bottom that has -3 at one side and +3 at the other and that’s the exposure scale and basically what that’s telling you is if the needle is in the centre of that scale you’ve got the correct exposure. Sometimes the needle isn’t visible but when you depress the shutter button halfway it will reappear and show you were about on that scale you are. And if it’s in the centre you’re perfectly exposed. If you’re to the left of centre (-1, -2, -3) that means your underexposed by 3 stops, or 2 stops or 1 stop depending where the needle is. This means you haven’t got enough light going into the camera to get the correct exposure (underexposed). You need to alter the exposure controls to allow more light in and get the needle into the middle.

And obviously if you go the other way (+1, +2, +3) your overexposed. which means you’ve got too much light going into the camera and you need to alter the controls to allow less light in.

As I’ve said before what we’re aiming for here is to get it right in the centre of that scale and we use the shutter, aperture and ISO setting to control the amount of light that’s going into the camera and by altering one or all of those settings we’re able to get that dial so it moves into the centre. We’ll talk about each of these controls in turn a little bit later on in other tutorials but basically we want the needle in the centre of that scale.

Fooling you’re cameras light meter
You’re cameras light meter will give you the right exposure 9 times out of 10.

However there are some lighting situations that will fool you’re camera’s meter into giving you the wrong exposure
such as:
• back lighting
• photographing something that is particularly light or bright
• or photographing something that is particularly dark or black
We wouldn’t discuss these circumstances at this stage as they are only likely to confuse you, but just be aware that they do exist. We will cover then in another tutorial”.