Never used one, but from the theories around it that I read on the internet, I was wondering whether a light meter that can measure incident light is useful for outdoor shots? Or is this tool mostly good for studio shots and controlled environments?

I shoot environmental portraits, outdoors.

  • 1
    This is a fine question, but I think you might get more useful answers (that is, beyond "yup", or "nope") by asking How can using an incident light meter improve my outdoor portraits?
    – mattdm
    Jun 22, 2015 at 13:28
  • Do you add your own light to the scene, for example by using flashes? Or modify the existing light with reflectors for example?
    – null
    Jun 22, 2015 at 19:36
  • @null I use external flashes on the scene. no reflectors. Jun 22, 2015 at 20:04

1 Answer 1


Incident Light Meters measure light that is directly hitting the subject as opposed to the on board Camera Metering which is measuring the reflected light. This generally means, light has to be fairly stable or controlled to retain correct exposure long enough when using an incident Light Meter.

A good example of using an incident light meter outside in bright daylight, would be capturing the Bride and Groom at a wedding.

To explain this further, if you were to take a reflected reading with your camera off the Bride, who lets say for the purpose of this discussion, is fairly light skinned with a bright white dress. The Groom on the other hand is a fairly dark individual with a dark suit on. Now, if you hover the camera over the Groom, you will find that the Groom is under exposed!

This is something very commonly observed when looking at wedding photos taken by family members where in bright daylight, white areas are overly bright and blacks areas are just too dark.

Things change when you use an Incident Light Meter. You hold the Light Meter with the white Invercone facing towards the Camera in front of your Subject IE Bride and Groom. The light hitting the cone is broken up and hits the reflector at the back of the cone which then measures the light and provides the correct exposure.

The Light meter can also allow for manually altering the aperture allowing for better control over depth of field whilst at the same time, altering the ISO and shutter settings accordingly to maintain the perfect exposure gained from the light hitting the reflector. As a result, both the Bride and Groom remain perfectly exposed.

The downside to using a Light Meter outdoors is that you do need to keep an eye on the light and take periodic meter readings to ensure correct exposure.

So, the biggest benefit of using a light meter outdoors is that you will always be able to gain the correct exposure of your subjects and not exposure gained from reflected light which may not always be just from your subject alone.

  • How, exactly, does changing the aperture/DoF bring the bright whites and dark blacks closer together in terms of dynamic range so that both are exposed correctly in the same frame? That seems to be what you are saying with... "Because the Light meter is able to manually allow you to change the aperture settings, you can control the depth of field. As a result, both the Bride and Groom are perfectly exposed."
    – Michael C
    Jun 23, 2015 at 0:10
  • I get your point and have adjusted the answer accordingly. Sometimes, what's in my head, doesn't always equate to the same thing on paper! It didn't make sense, hope it's a little better now Jun 23, 2015 at 0:25
  • Your answer explains what a incident light meter does, but I still doesn't understand how an incident light meter can improve outdoors portrait. What's the difference of exposure if I use the spot metering feature of my camera ? As for reflected light, it seems to me that it will still hit the camera detector and mess with the exposure, regardless of the incident light detector indication... Am I missing something?
    – Olivier
    Jun 23, 2015 at 20:34
  • Spot metering will only take an exposure of the actual spot. Outdoors in bright sunlight, the spot metering will be different for both the bride and groom. Spot on the bride will make the groom under exposed and spot on the groom will make the bride over exposed. The light meter will accurately measure the light hitting them both and provide the ISO, aperture and shutter settings that will be used on the camera set to manual exposure. Anything other than manual and the camera will provide reflective exposure Jun 23, 2015 at 22:19
  • Thanks for the clarification. It still seems more complicated to use a light meter than using a picture's histogram... For portrait, the aperture has to be fixed for the desired depth of field, so you are left with the usual shutter speed / iso tradeoff. I think the semiautomatic aperture priority mode will do a more than decent job, you just will have to take a few shot to come with good settings (mostly finding the right iso compensation to get what you want).
    – Olivier
    Jun 25, 2015 at 21:03

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