There are two kinds of hand-held light meters: incident meters and spot meters. An incident meter measures the light falling on a subject, while a spot meter (also called a reflective meter), measures the light reflecting back at you from the subject.

Incident meters are great for metering light falling on actors or products you are shooting. They are the best tool for measuring light ratios (key, fill, backlight, etc.) on your subject.Spot meters are great for understanding the light levels in a large scene or a landscape. They are a great tool for photographers who use the zone system (developed by Ansel Adams). Light meters in still film and digital cameras are really spot meters. You look through the viewfinder, and the meter measures the light reflecting back at you. Some evaluate the light levels of the whole scene, some operate by measuring the light level at spot in the center. It used to be that every photographer carried around a handheld light meter. As light meters in still cameras became more sophisticated, there was less demand for the handheld variety. But many photographers still rely on their incident meters as the most accurate way of measuring the light in a scene.

For cinematographers and studio photographers, light meters are not a choice but a necessity. Working with film requires accuracy of exposure. There’s no bracketing, no instant digital feedback, and no trial and error in filmmaking. The same goes for studio photography, whether shooting film or digital. If you are working with a crew and a model and stylists and make-up artists, you only get one shot to get it right, and the costs are high. Understanding your light helps you get it right the first time.

But for the everyday digital photographer, why use handheld light meters? There are many different options for metering the light in most new digital SLR’s, so why carry around extra gear? Well, that’s a good question. For many people, one answer is habit. For others, it’s a feeling of control or maybe that meters are really cool looking (which they definitely are). Some say it’s another gadget to sell on eBay.

For me, I like my light meters because they help me better understand the light. Photography for me is a way to capture the light in a permanent form that I can look at again and again. Understanding how the light behaves and knowing what the general light levels are in my environment help me to be a better photographer. One of my favorite cinematographers, Haskell Wexler (One Flew Over the Cuckoo’s Nest, Mulholland Falls) wears his wherever he goes. My idol, Conrad Hall, was able to look at his hand under the light and know without his meter that it was an F/5.6. How cool is that?! I meter things all the time. That is why my light meters are on my favorite things list (DP Blogs Project of theProduct Shot Outside Month).

I have three light meters, a Minolta Spotmeter F, a Minolta Autometer IVf, and a great workhorse Sekonic Studio Deluxe 2.

I took the light meter shots you see above outside using my homemade diffusion panel and a bounce card.