There’s no question that in some complex metering situations, it can be tough to figure out the best exposure with the meter in your camera. An incident light meter can be quicker, faster, simpler, and more accurate in some of those same situations. Some incidents light meter can also measure light from an electronic flash.
An incident light meter is so quick and simple to use because it meters the light falling on the subject, rather than the light that is reflected off the subject. This changes everything. To learn why this is important and how to use one, go here.
My favorite incident light meter are made by Sekonic and Gossen. Polaris meters also have an excellent reputation and a lower price. Minolta meters are worth finding on the used market.
The two meters I use the most are the Sekonic L-358 and the Gossen Luna-Pro F (no longer manufactured but worth finding on the used market). Both meters will measure incident light and light from an electronic flash.
My selection of the best light meters is here.