Why use a light meter when the in-built meters in today's cameras are so good? It's true that modern cameras have highly reliable meters and take a lot of the guesswork out of photography but, even today, light meters can be invaluable in certain situations, such as when you're shooting environmental portraits and using flash.

Prior to using a light meter, my tried and tested approach to flash photography was to take an ambient reading by using the camera's P mode. I'd then switch to Manual and dial in the P settings, increasing my shutter speed to lower the ambient light (bearing in mind that if I went below a shutter speed of 1/250s and I wasn't using high-speed sync I'd get banding). My next step would be to add any number of flashes, in manual mode, starting them off at low power and adjusting the power up and down as required or moving the position of a flash itself. (I could also have used the flashes in TTL mode to get an automatic reading but I prefer manual).

This approach works fine but there's a lot of guess work involved in choosing the power of the flash to get an accurate exposure. Sometimes I'd be farther off than I'd expect and it would take a number of tweaks before I had the exposure I wanted. Which isn't incredibly bad but I really want to be quicker and more accurate when I'm on a job with a client.

After some research, I purchased a Sekonic L-308S light meter. What this simple, lightweight meter lets me do is establish a ballpark aperture (read flash exposure) for my subject depending on the shutter speed and ISO values I want to use, and not guess. This is useful as it saves me time and helps, I believe, add another layer of professionalism to my work for my clients (especially if I am showing them unedited shots on location, e.g. using an iPad).

How I use a light meter for flash photography

  • Dial my desired shutter speed and ISO settings into the light meter and position it in front of the athlete / model's face.
  • Trigger the flash using a handheld Pocketwizard Flex TT5 transceiver and note the aperture reading the meter has produced. (If required, I'll change the shutter speed and ISO settings until I have the aperture I want).
  • Dial the light meter settings into the camera, replace the TT5 and start taking shots.
  • Make any adjustments, as required. (If the light changes dramatically, I'll start again).

There's plenty of other things the Sekonic L308-S can do (see the instruction manual) however if I'm outdoors I use it simply to get a ballpark flash exposure and, for that purpose, I'd recommend it as lightweight, simple to use and reliable light meter for adventure sports photography (though see my words below about using a sync cord).

What I like about the Sekonic L-308S light meter

  • Ease of use - Trigger the flash using the light meter and it immediately gives you a suggested aperture reading for the shutter speed and ISO you want to use
  • Adjustability - If you don't like the effect you get with your selected shutter speed or ISO simply change the values in the light meter and it will give you a new reading. Dial these into your camera and you're ready to go again.
  • Reliability - It's simple and it works quickly and reliably every time (though see words below re cordless mode)

What I'd change

  • Functionality - It won't fully work with my Pocketwizard wireless transmitters. I'd need to trade up to the Sekonic L-358, 478DR, L-758D or L-758DR models instead.
  • Reliability - There's a cordless functionality but occasionally it doesn't work in bright light outdoors and especially if you're too far away from your subject. I bought a 5m sync cable to remedy this and it works 100% of the time.
  • The shutter on the Lumisphere (light reading bulb) commonly opens up when I remove the meter from its case. As it's sensitive to damage, I'd prefer a simple locking mechanism to prevent this.

Alternatives