Basics - Understanding Your Light Meter

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Light Meter

Light meter

A sample of how your in camera light meter may appear, with prefect, under and over exposure shown - Please feel free to use this image just link back to this page. İAshley Beolens

As you will no doubt know photography is all about capturing light, and in order to do this we need to measure the light accurately. Fortunately most cameras come with very good built in light meters, and this tutorial is going to focus on how to read and use those light meters (for those wanting to know more about external light meters sorry this isn?t the page for you)

The light meter in your camera will be a simple affair (each make will look slightly different but they should all be similar) a series of dots numbers and an indicator showing whether you are over or under exposing the shot. Each dot will represent a partial stop; each number will indicate a full stop (usually 2 either way), with the ideal position being in the middle. You can see the light meter either through the viewfinder (under where the image is) or on the display window on the top of most DSLR cameras.

The image to the right should be similar in design to your cameras light meter (it will not be exact, I have created this as an example). In order to under expose an image the indicator line will need to be to the left of centre, to over expose the photograph the indicator line will need to be to the right of centre.

One thing it is worth understanding is that your light meter reads everything as grey. in fact 18 percent grey. What this means is that if you meter off something of that mid grey then that subject will be exposed perfectly and so will all other tones.(This is why 18 percent grey cards are a great tool).

You can control whether you under expose, over expose or setup at the right spot by using your aperture control, shutter speed or film sensitivity or a combination of all three. For details on how to do this please read Basics ? Understanding Exposure. Changing any of these will alter where the indicator appears along the line, towards the minus (-) number will be under exposed, towards the plus (+) number will over exposed.

Fortunately this is only a short tutorial hopefully now you will know what you are looking at when you look at your light meter.

Ashley Beolens