Spot Meters
The Ultimate Tool For The Thinking Photographer?

Photos © 2004, Joseph A. Dickerson, All Rights Reserved

Anyone who knows me recognizes that I have a thing for light meters. I own, and regularly use, several and have collected a number of antiques that decorate the shelves of my office. This obsession started when I was a kid and my dad had a really neat General Electric light meter with lots and lots of cool looking numbers. Much later, when I became a serious photographer and began to make my living shooting portraits and commercial work, I realized that just as there is no universal camera, some light meters function better than others for a particular application. Studio photographers, especially those specializing in portraits and product photography, are probably best served with an incident light meter. On the other hand, fine art photographers who shoot predominantly landscapes usually prefer the extra control a spot or narrow angle meter affords.

You may already be conversant with the terminology, styles, and features of the various light meters but for those of you new to this subject let's review some of the important points of light meter shopping.

Here's a gaggle of spot meters. The Soligor Digital Spot Sensor has been discontinued but is still available as the Adorama Digital Spot Meter. The Sekonic L-778 is also discontinued, but I included it, as it is one of my favorites for implementing the Zone System. The Sekonic L-608 and the Gossen Starlite bring new meaning to the term multi-tasking. The Starlite also has one of the slickest Zone System modes of any meter I've tested.

Meter Types
First, there are two basic types of light meters: incident meters and reflected meters. Incident meters read the light falling on the subject utilizing a hemispherical dome. It's the half Ping-Pong ball looking thing you see on incident meters that integrates the light readings. Reflected light meters have a sensor that reads the light bouncing off the subject and these can have a wide or narrow angle of acceptance.

Each meter type has its advantages and disadvantages. With incident meters, because the dome is three dimensional, the light falling on the subject is averaged, resulting, most of the time, in an accurate exposure recommendation. Studio photographers love incident meters due to the ease of comparing multiple lighting sources, setting lighting ratios, or balancing ambient and flash lighting. Once the lighting ratios are set a single reading is all that is required to determine the exposure values.

I wanted to maintain the dark moody feel of this scene. Spot metering the dark shadows in the lower right rocks and then checking the white foam of the breaking waves ensured that all the tones would print with texture.

However, in situations where the scene before the camera is extraordinary in some way, for example a snow scene or a black sand beach in Hawaii, incident readings could be unreliable. Scenes with predominantly light or dark tones could easily cause overexposure or underexposure. Some photographers eventually learn to recognize these situations and compensate, but most never figure it out and spend their lives bemoaning the photos that "didn't come out." To reiterate, incident meters are very accurate and easy to use over a wide range of subject and lighting conditions, but they can be fooled. And that, my friend, is the reason there are spot meters.

Pick Your Spot
Spot, or narrow acceptance, meters are simply reflected light meters that see only a small portion of the scene. This narrow angle of acceptance is generally in the range of 1-5Þ. A standard reflected meter usually has an angle of acceptance of approximately 30Þ, so you can see that a 1Þ spot meter is really narrowing down the area of sensitivity considerably. In real world terms the area read by a 1Þ spot meter at a distance of 20 ft is approximately 5" square, about the size of a post card.

This selectivity allows the photographer to measure discrete tonalities within the scene, usually from the camera's position, and base the exposure on the way he/she wants those tones to reproduce in the final image. After all, it's all about control isn't it?

With a spot meter this exposure was quite simple to solve. The dark rocks in the foreground were "placed" on Zone III and I then read the surf and the clouds to make sure they would retain some texture.

Zone Alert
You've heard about the Zone System, right? Well, you've probably heard that the Zone System is nearly impossible to understand, requires math skills just short of Hawkins and Einstein, and that Ansel Adams kept the three most valuable zones a secret. Not so. First, Adams only kept two zones to himself. (Sorry, couldn't resist!) In truth, the Zone System can be explained in one sentence: "Expose for the shadows and develop for the highlights." That's the whole premise of the Zone System. Exposing for the shadows is the part that is relevant at the moment.