Using Handheld Meters In The Digital Age; Expanding Your Exposure Options
Camera metering systems are great. No doubt about it. But there are times when you might want to expand your metering options, such as for flash or strobe studio and outdoor photography, for really tricky light and when you want to make a number of measurements within a scene, that a handheld meter will come in, well, handy.
Metering Opations: Reflected Light Readings
A typical handheld exposure meter actually provides you with two ways to meter. First, there’s reflected-light, or reflectance, measurement. That largely works the way the camera’s metering system works. Point the metering sensor at the subject and take a reading of light reflected off the subject. Typically, a handheld meter uses a sensor that reads an area roughly equivalent to a 50mm lens on a full-frame D-SLR. But increasingly handheld meters are designed with spot metering, usually a very well crafted, very precise measuring angle of 1º. You’d need an extremely long lens to even approach that degree of precision when metering through your camera (depending of course on subject distance).
You can easily target a subject tone, taking readings of a key highlight, key shadow value, or midtone value. That way you can “place” a certain tonal value at middle gray and make very expressive, and/or very precise decisions about exposure and tonality.
Incident Light Readings
Most handheld meters also sport a plastic, white hemispherical dome. Thisreads light falling on the subject, or incident light. Thedome reads light gathered from an area covering 180º. And the way we use incident metering is, we hold the meter at the subject position and point the dome at the camera.
This is something the camera meter cannot do and the technique largely avoids undue tonal/brightness influences (which might make you use exposure compensation to get a good reading) and the influence of reflections. It is surprising how easy getting great exposures can be when you eliminate those two variables. And many digital photographers have found that using handheld meters ups their success rate considerably.
Electronic Flash, and More
When using studio strobes or flash, a handheld meter always makes a big difference in results. Many meters can trigger flash remotely or via a sync cord to make readings, again from subject position. There’s no question that a handheld meter is a necessity for studio or home monolight and flash work, especially when more than one light is being used in the setup.
And once the reading has been made you can lock it in on Manual Exposure mode and not worry for the rest of the shooting session. Of course you would have to make new readings when rearranging lights or, say, swapping out an umbrella for a softbox.
A handheld meter also lets you take multiple readings, thanks to the built-in memory found in numerous models. I find this invaluable when confronted by tricky exposure situations or unusual contrast in ambient, low light, and even outdoors under harsh lighting conditions. I’ll take separate readings for a key highlight and key shadow and check the contrast ratio. More readings can be taken if needed. This helps determine if the contrast can be handled by the dynamic range of the sensor; if not I’ll take steps to control the highlight accordingly.
So while there’s no question that your in-camera meter is an amazing light reading instrument, handheld meters still have a very useful part to play in a digital photographer’s life.