This time around, we're going to talk about METERING. Let's dive right in.
What is METERING and why is it important?
Basically METERING is measuring the light. It's extremely important, because it lets us know how to expose the scene.
Sounds simple, right? Unfortunately, it's not as simple as you might think, as there are several types of METERING.
Cameras use reflected light METERING. Almost every camera in existence takes the reading of the scene and tries to make the exposure for the METERED area to be 18% reflected gray. Not based on color, but on a comparison to a gray level that reflects 18% of the light that hits it. Ansel Adams called this ZONE V.
Evaluative METERING- If you haven't read your camera manual, or you've decided not to change your settings, you're most likely using Evaluative METERING. This means it's averaging out the light over the entire scene to get a basic ZONE V exposure. This is good for most photos, especially those that don't have too much range between lighting levels.
Partial METERING- this is set from your menu and decreases to amount of the scene used for METERING. You can set this on some cameras to different parts of the scene.
Spot METERING- In this mode, the camera METERS off a small spot to set the exposure. This is great for tricky lighting, and for more control of your exposure. It also allows you to get some idea of the range of a scene's lighting for manual exposures.
Generally speaking, using your evaluative METERING mode will give pretty good results. There will be times when switching to partial METERING, or even center weighted, can give better results.
The easiest way to METER a scene is to get an 18% Gray card. You have your subject hold it up, zoom in and METER from that. Take the settings you read and enter them into the camera in manual mode. As long as the light doesn't change you will have a good exposure. Using the gray card allows your camera to METER from a target that matches what it is trying to set. This is best accomplished in spot METERING mode, unless you fill the viewfinder with the card. If you do that, then use evaluative METERING, which will average out the light over the card and result in better exposures.
For more info an METERING, check out our Intro to Photography page. The info there is a little more in depth and includes an example. Also visit Cambridge in Colour, their explanation really clarifies a lot!
Don't forget, if you have any questions, ideas, tips, or comments, post them. You can post them here and on our Facebook page.