Today I’m going to show you how to use a handheld flash meter, and before we get started, I want to let you know that is not necessary for you to use a handheld flash meter in order to get great flash photos.
so in order to demonstrate this, I’m going to take a self portrait, and before we turn on the flash meter, before we turn on the flash, before we do anything else, we have to set the settings on the camera for our ambient light.
I’ve already done that, and currently, the camera’s set to ISO 200, which is my lowest ISO, a shutter speed of 1/250th of a second, which is my sync speed, (and both of those settings were chosen in order to black out the ambient light, because I want only the flash to show in these photos), and finally, I chosen an aperture of f2.8. The reason I chose f2.8 is because I want any detail that might show up in the background behind me to just go out of focus with a relatively shallow depth of field.
Now with your camera settings set, you’re ready to get your flash meter turned on and get your flash exposure dialed in.
Here’s how you do it. You first have your flash turned on, then you turn on your flash meter, and for this demonstration, I’m using the Sekonic L-308s handheld meter.
Now one of the really important things to know is that the little dome on the front has to be over the photosensitive light meter in order to get an accurate flash reading. You also need to make sure that your mode is set properly, because you can use this meter for ambient light and for flash.
In order to change the mode, you just press the little mode button, and then you need to set the settings on the meter to match your camera settings, specifically the ISO and the shutter speed, but not the aperture.
So the first thing is to change the shutter speed, and in order to do that, I use the side buttons. Once I’m had 1/250th, I can hold down the ISO button and use those same up and down buttons to get myself down to ISO 200.
Once those two settings are set, you’ll see that there’s the F here and 0 underneath it, and no buttons that indicate we can change the aperture.
This is where the light meter is going to display what the aperture on the camera should be, in order to get a good exposure for the flash at its current power.
So to demonstrate that I’m going to trigger my flash. If we take a look, my flash is currently set to 1/4 power.
Now in order to get this to work, you press a button on the side of the meter which makes the little square indicator flash, indicating that the meter is ready to take a reading. Then you hold the meter up to your subject where the light is going to be illuminating them. Then you fire the flash.
In doing that, we get an F reading on the meter, and our F reading is an 8.6. So it’s roughly f8 plus 2/3 of stop in terms of aperture. Now we want this to read f2.8 because we’ve set the camera aperture to f2.8.
If we take a photo at this flash power of one quarter, it will be too bright. So we need to get this to read 2.8. Now we can calculate this pretty easy, we’re at f8 + 2/3 of a stop. From 8 to 5.6 is one stop, from at 5.6 to 4 is two stops, and from 4 to F 2.8 is three stops.
So we need to go about 3 and 2/3 of a stop down in flash power to 1/64 + 2/3, and now I’m going to test it again, and now we get a reading of f2.8 + .2, which in my opinion is close enough.
What that means is this light is dialed in for a perfect exposure, and that’s basically how you use a light meter for flash photography!
I used to be scared of my flash, and I understand how intimidating flash photography can be, but a flash is just a tool. Once you understand how that tool works you’ll be using your flash to create photos that used to seem impossible.
If you want to master your flash and take those amazing photos, check out my Understanding Flash Photography Video Course.