Light Meter Basics: Exploring Photography with Mark Wallace

Hi everybody and welcome to another episode of Exploring Photography right here on an AdaromaTV. I am Mark Wallace and we are dedicating a few episodes of Exploring Photography to basic studio lighting
techniques. In this episode I’m going to show you how to use a light meter. Now last episode we talked about something called sync speed, thats the fastest shutter speed we can use with our flash, and that helps us to understand how a light meter works.
How you set it all up in. A light meter basically you set up your ISO and your
shutter speed and it tells you what aperture to use when you’re taking a
photo. Why is that? Why is it always telling you the aperture setting and
nothing else. Well to understand that we need to understand
the different kinds of metering. The through the lens metering our cameras
used and the meeting that we use in a studio with a light meter. S to understand
all that here’s a cool animation that I made just for that. There are two basic methods of metering light. Incident metering and reflective metering. Your
camera’s built-in light meter uses reflective metering. Here’s how it works Light travels from its source and
reflects off the subject and into your camera’s lens. When the light enters your
camera it travels down the lens and then hit’s a mirror, the light is then
reflected at a 90 degree angle up into the pentaprism and finally out the eyepiece. The mirror and pentaprism allow us to see exactly what’s coming through the
lens. Your cameras light meter is inside the pentaprism.This built-in light
meter is what your camera uses to show you meter readings in the viewfinder.
Some of the light is allowed to travel through the main mirror and hit a
secondary mirror. This smaller mirror reflects the light onto the autofocus
sensor. This sensor is what your camera uses to focus the lens. When you press
the shutter release button both of these mirrors move out of the way, the shutter
opens and the exposure is made. When you’re using flash heads that are synced
to your camera they don’t fire until the shutter is completely open. Which means that your built-in light
meter has no way of seeing and metering this light. For studio work you’ll need
an incident light meter. Instead of metering light that reflects off the
subject, incident metres measure the light that is actually falling on the
subject itself. You simply place the meter next to your subject and take a
reading. In a normal studio setup you’ll set your camera and light meter to the
same shutter speed and ISO setting. When you take a meter reading, the light meter
will tell you the correct aperture value and you’ll set your camera accordingly.
Once you’re all set up you only have to worry about the aperture value. Well now
we know about some of the theory that is involved in using a light meter now
let’s put that into practice and get some handle on how to actually works. Now the question that you might be asking yourself is ‘Mark, which aperture value is
the correct aperture value?’ Well that depends on what you want to do. So to
walk through that and how to adjust all this stuff I’m going to ask Kelly to
join us and since Kelly is the tallest model in the world I’m going to have you
actually sit right there and we’re gonna go through some of these things. Now when we use a light meter if you go back a few episodes of Exploring Photography you’ll
understand that you need to point this lumisphere at that camera when you’re
starting out and so that’s what we are doing. As far as the settings go I have told my
light meter that I’m shooting at ISO 200.I have set it to my camera sync speed which is
180th of a second. I have also set my camera to ISO 200 and a 180th of a second. All that remains is the aperture value
and so what I’m doing here is I have a little remote. When I push the test button that
makes my flash fire and so I can push the button on the side of my meter and
then push this and then my meter tells me that this light is metering at f/2.0. That is not the aperture value that I want. Why is that? Well f/2.0 has really shallow depth of
field, in fact her entire face is not going to be in focus and so for this
portrait what I want is an aperture value of about f/10 maybe f/11 because that will give me everything in focus, from her nose all the way to the back of her head and that
is what I want. So what I need to do is I need to go from f/2, which isn’t
very much light, that means our aperture has to be really wide to bring in that light. I
need to increase the power of this flash until it gets to f/11. Now on every single
flash speedlite, studio, strobe doesn’t matter there’s some way, read your user manual, there is some device
some dial that will allow you to increase or decrease the power. On this
Profoto B2 it’s just this big dial here. So I’m going to increase that and so i’m going to put that up a little bit more and then hit this little test button and come back
over here. We’re going to see where we are now. Now we’re at f/5.6. So not
enough. I have to keep going. So I’m going to keep going until I have this set to more
power and then we’ll meter at this one more time and now I am metered at f/11.
Once you use a flash for a little while you’ll get to the point
where you know pretty much know exactly where you need to be every time to hit f/11 or
f/4.5 or f/22 and it’s really fast and so you don’t have to worry about that, with a little practice you’ll be there. So now we’re set at f/11. So what I did, let’s
review. ISO set on the meter the same as in the camera. Shutter speed that’s set on the meter same as in the camera and then I metered and adjusted this until I
got it to an aperture value that I wanted, which was f/11. Now the only thing that’s left for me to do is set my aperture to f/11 on my camera and take some pictures. So let me do that and I’ll show you the results. There you have it using a light meter in
the studio is pretty simple. Remember you set your camera and meter to the same
ISO and shutter speed which is our cameras sync speed and then you meter
and adjust your flash until you get to the aperture value that you want. Now of
course there’s more to metering than just that but the good news is over at
the Adorama Learning Center we have hundreds of videos about shaping
light using light ratios, light modifiers, bouncing light, anything you can think of
its over there and it’s absolutely free so check that out. Also don’t forget to subscribe to AdoramaTV it’s free and that way you get all the good stuff from me and everybody else that contributes every single day, so do that right now. Thanks again for joining
me and I will see you again next week.

34 thoughts on “Light Meter Basics: Exploring Photography with Mark Wallace

  1. Great series, thanks. I never used setup like this and it's not clear to me why not measure the light with the meter from the position where camera would be? It seems more logical to me as it would correct for reflectivity of the subject. Is such approach possible? Do you need to use different settings on the meter for this? Light would certainly be weaker once reflected and dispersed.

  2. Great video!!! but a little constructive criticism he shouldn't assume everyone is using a camera with a mirror, the mirror really has nothing to do with what he is explaining.

  3. Great tutorial Mark, however I'm not sure if the model was a little nervous or if that's her natural persona, but her energy was quite dull.

  4. I have the Sekonic L478DR. Let's say I want to shoot at 2.8, darken the background and get a 30% flash to ambient mixture on the model. Do I adjust the shutter speed then? And won't the shutter speed effect the flash output. I'm struggling with how to get the flash to ambient mixture I want.

  5. Thank you ! I been trying to learn flash photography lately , and this is the first time it made sense to me! Thanks

  6. Unfortunately there are a lot of people outside saying that they don't need a lightmeter. Sorry, they don't understand the purpose of a lightmeter! The most expensive camera can't do the same as an external lightmeter!
    I own the same lightmeter you are using, the Sekonic L308S. It's not too expensive, small and light.
    Thx for your tutorial. Hope that people now will understand!

  7. If i do an incident metering on the model face I have f11 as in the video. But the sensor sees the reflected light…so as in this case the skin of the model is dark I thought we needed a little compensation to obtain a correct tonality on the skin. Am I right?

  8. Don't you guys recognize the symptoms of the "no smile model"? The poor thing was so nervous! Watch the video again and notice how fidgety she was. Odd for a pro model to be nervous like that…but she may NOT have been a pro or accustomed to being videoed. Yeah…she'll need to overcome that nervousness if modeling is going to be a career choice.

  9. If the light meter can only record the amount of light when the mirror is down then how do you explain the metering in live view?

  10. This is great! So I'm watching the video from the Adorama website and wanted to leave a comment, which you cannot. After reading some of the comments I can tell I'm not the only person that would ditch that self proclaimed model. Was a real model with personality and warmth not available in New York?

  11. This is brilliant simple yet informative and practical tutorial thank you very much and keep the great work good luck

  12. Mark please what about COMPENSATION EV i have Nikon d7200 but if the compensation its on 0.0EV my pictures are over expoused…i all ready adjust at -1 EV but i’m not sure if its the correct….my pics seem to be balanced but i have steel doubt… please help. Thanks in advance

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