During my tenure at film school I never seemed to be able to fully comprehend taking a light meter reading (thankfully, I became a screenwriting major). While most DIY-ers are shooting digital with internal meters, knowing how to set up a shot using a light meter is a must if you want to move onto professional film making.

First you need to know the terms: “Film speed” is a number given to film stock to indicate its sensitivity to light. The higher the film speed number (or ISO rating) the higher the sensitivity to light, which in turn means the coarser the grain and the lower the sensitivity to detail (and vice versa). Set the ISO number on your light meter so that it will see the light the same as the film in your camera.

Then there is the “shutter speed”, a number that signifies how long the shutter is opened to let light onto the film. It’s measured in fractions of a second because it calculates both the opening of the shutter to expose the film and the closing of the shutter to advance to the next frame – two movements per frame and thirty frames per second gives you a shutter speed of 1/60. Get it?

Once both values are set on the meter you’re ready for the reading. The most basic meter is the incident, which measures the light from the source before it bounces of another surface. You take the reading from the front of your subject with the dome facing the main light source or the camera. Once the button is pressed, the meter takes an average of the light and shadow values giving you an f-stop value which will inform your aperture setting. In the end you’ll have a well-balanced picture that really represents your overall mastery of all things film (or you won’t look like a dork on a film set).

Can't understand my babble? Industry pro Bill Holshevnikoff might be able to serve you better with his in-depth analysis of the subject.