Do I need a light meter?

If you’re reading this you’ve likely just spent a bunch of money on lighting equipment and then realized, “ah man everyone says I need a meter too?” Do I really need a light meter?  This is a common question when someone is first getting into studio lighting.  Ask any pro or instructor from a class you’ve taken and the answer will always be yes.  But do you really need a light meter?

What does a light meter do?

Let’s assume we’re dealing with studio lights here. In non-technical terms a light meter allows you to quickly measure the power of a single or combination of multiple lights.  Many first timers think a meter tells you what power level to turn your strobes to.  This is NOT CORRECT.  It actually only tells you what power your strobe is currently at.  It does this by outputting the F-Stop of the strobes and any available light the meter sees. It DOES NOT give you a power reading like, turn strobe to ¼ or ½ power. You set the ISO and Shutter Speed in the meter, press the button and it comes back with an F-Stop number that you would set your aperture to on camera for a properly exposed image.  You know that you don’t want to adjust your aperture so you turn the power of the strobe up or down instead.

How It Works

Say you wanted your strobe to be set at f8.  You meter the strobes and the light meter shows they’re at f11.  You now quickly know that you need to turn the strobe down because you’re trying to get to f8.  Then you meter again, f10, turn down again.  Meter again, and f8, perfect.  Without a meter you could have done basically the same thing but it would have taken 3 shots to get to the same point.

Finding Lighting Ratios

You can also use a light meter to determine lighting rations. Say you’re doing a portrait and you want a 2:1 ratio.  2:1 means that the main light is twice as bright as the fill light.  You can use a meter to measure the first light and then again to find the equivalent value of the other light.  Or maybe you want the background lights 2 stops brighter than the main for a pure white backdrop.  The bottom line is that a meter is the fastest most accurate way to set your lights.  This is why a pro will always say buy a meter. It saves time and it’s dead accurate.

Don’t Buy a Light Meter Yet

If this is your first time in studio lighting none of that previous information likely made sense.  This is why I recommend first timers DO NOT get a meter right away.

So you’ve got your new strobes and softboxes and reflectors and…and…and. Feeling overwhelmed yet?  Don’t worry most people do when they start out.  The most important thing is to get practicing with your strobes and modifiers and learn how they work.  A light meter can be a major hindrance to a rookie photographer.  Suddenly you’ve got another piece of high tech gear that will make no sense until you understand what you need it to do. What’s the point of measuring a light if you don’t know why you need to measure that specific light in the first place?  What is that light trying to accomplish? Do you really know that you want that light at f8 by randomly guessing?  Taking a shot and seeing the effect it has on the photo is much easier to understand at first.  You can use your eyes to see if it’s too bright or too dark on the camera LCD and then adjust.  The histogram on your camera LCD will also confirm if the photo is exposed properly. 

From years of experience a pro photographer knows what they want.  They know they want that light at f8 and a light meter gets them there quickly and accurately. This is why a pro will always say buy a light meter, but they often forget where they started as well.

Practice, Then Buy

It’s nothing but practice to understanding how your lights work. Start with one strobe and take a shot.  Add in a reflector and see what happened?  Add in a background light. How did things change?  Once you start to see these changes and how you want to manipulate them for your overall photo goal, you’ll get to the point where you start seeing lights in f-stops.  Once you start getting to that point it’s time for a meter.

A good meter is going to set you back $350.  This may be half the price you just paid for your lights.   Save your money for a while.  Think back to when you bought your first DSLR.  You were so excited to get that body and the kit lens.  A year goes buy and you start to realize. “Hey this kit lens is a real piece of crap for low light.  I need a 2.8 lens.” Then you realize, “Hey this pop up flash is a real piece of crap for portrait lighting.  I need a speedlite.” Then “Hey this Speedlite is a real piece of crap for studio lighting.  I need a strobe kit.”  I think you get what I’m trying to say.  The light meter is a natural progression in equipment but only after you come to that point of thinking “Hey this taking 3 photo’s to meter a single light is really slowing me down.  I need a light meter.”