Photos by Calvin

Sekonic L-358 Light Meter (chimping is for monkeys!)

It took me some time to realize how useful an external light meter is, but I finally picked one up – and boy am I glad I did!

Light meters tend to have a negative stigma attached to them. They are often seen as crutches – but who said crutches are bad? Crutch or not, a hand-held light meter proves to be useful for both ambient and flash lit photography.

Well, you might ask, “what’s wrong with my camera’s built in light meter?” The problem is inherent to all reflected-light meters, including the L-358 when used in reflected-light mode, which “attempt” to provide an exposure setting to make the scene appear as it were a middle gray. Reflected-light meters read the light reflected (duh) FROM the subject. Incident light meters read the light falling ON the subject.

If you use a reflected-light meter to measure the light reflecting from a snowy outdoor scene, the snow will appear gray in the resulting image if you use the reading as-is. What’s happening is a reflected-light meter (i.e. your camera) will mistake the light reflected off the snow as too bright and will try to compensate by underexposing the shot, resulting in gray snow. Alternatively, if you were measuring a very dark subject in the same light (a black cat in a coal bin, for example), the subject would appear gray in the resulting image. And the opposite applies here, the reflected-light meter sees it as too dark and will try to overexpose the shot, resulting in a gray cat & coal. In both cases, though, if you used an incident meter such as the L-358 with the white hemisphere mounted, both subjects mentioned above would essentially appear the way you see them in real life. Reflected-light meters are easily fooled into giving you an incorrect reading when the subject’s coloring or reflectivity are not equivalent to a mid-scale gray.

Too many folks think that their magical automatic cameras should do it all perfectly, and that just does not happen.

Using a camera’s meter in any of the automated modes (anything other than “M”) turns the metering decisions over to the camera. Even if you dial in Exposure Compensation (EC), the camera is still doing most of the “thinking” and can change its reading (and thus the exposure settings for an image) when you aim the camera at a different part of a scene which reflects a different amount of light back to the camera even though the light source is not changing. For example, if you are shooting a portrait in Av (aperture priority, a semi-automatic mode), then you will notice the shutter speed will likely vary slightly from shot to shot even though nothing has changed.

This all said, a reflected-light meter can be used essentially as a pseudo-incident meter if the meter is aimed exclusively at a target of known reflectance. 18% gray cards are a common and popular alternative.

Now, as far as flash photography goes, I find a flash meter (i.e. L-358) invaluable. Until now I have been using the “guess and tweak” method because the camera’s meter is totally useless for manual flash systems. A flash meter eliminates all the guesswork and chimping. You don’t have to fire test shots and tweak or trust the LCD on the back of your camera. If you shoot similar subjects in similar environments repeatedly, there is no doubt that you will develop a sense of what settings and ratios to use. However, I don’t think this necessarily makes you a good photographer – just an experienced one. If you ask me, understanding the use of a flash meter makes you a smart photographer. And if you use one correctly in a practical situation, I believe you will be less focused on trying to dial in the settings for a correct exposure and more focused on shooting your subject.