Measuring Light and Achieving the Correct Exposure

Get the measure of light with this simple class.

How do you measure the power of the light from your studio lighting to ensure perfect results? Do you apply visual, theoretical, histogram or light meter readings to achieve the best results?

Karl discusses the best ways to measure light and achieve the desired exposure as well as the limitations of the above methods and why it’s important to truly understand light if you want complete creative control.

In this class:

  • Different methods for measuring light
  • Light meters — what use are they in digital photography?
  • Assessing exposure visually
  • Combining aperture and shutter speed to achieve desired exposure
  • Reading histograms
  • Correctly exposing for different textures

Questions? Please post them below.

Comments

  1. Hi Karl

    Thanks a lot for the great course that you are teaching especial to us who are still new in this field.

    I have one interest on how to get the differenr exposure using a colour checker comparison.Do you look at percentage of RGB values and if correct by how much you accept as 100%correct or one over or one under exposed.

    Thanks I will check for a reply

    1. Hi, no I never do that. I only use the colour checker card to compare colour values and measure the neutrality of greys. Never forget, there is no ‘correct exposure’ if there was nearly all of the best photographs ever taken would be incorrect.

  2. Hi Karl, firstly thanks for every video you post..
    I have a Gossen and a Sekonic 308 light meters from the days of film, since I was a photography students. Yes I can say that you made your point about the looks of the final image and how the meter can point us to the wrong directions. Your point about checking the LCD screen is never gonna give us the exact result cause the image shown is Jpeg. But as we shoot RAW there’s more information which is still hidden.
    I don’t use the light meter so often, I normally use it just to start my exposure to be as close to the metering as possible.
    Sometimes when I judge the image from my camera LCD I still have to increase the exposure in post by about 25-30% but when I use the meter it’s spot on.
    My camera LCD is always set to mid brightness.
    This is a very good lesson and through I understood so much about lighting as well as all other courses that you post here.
    Thank you so much

  3. Hi Mr. Karl first of all thanks for your classes they are amazing. My problem is that as a beginner photographer I’m still using one and very rarely two flashes. And every time after photo shoot when I look at my images on the computer they appear to be a little bit under or over exposed. Sometimes I like to create dramatic portraiture and under exposing background for the purpose and trying to keep the subject in normal exposure as need to be.And in those situation it’s very important to get your exposure right because it’s hard to fix it in post. very often subject become over exposed. you know what I mean. I was told that most of the cameras view winder doesn’t show the full truth and I need to buy light meter. I honestly really don’t like Light meter. And also I never touch LCD brightness on my camera. I would be really appreciate your advice or help because this situation really giving me a hard time in my photography

    1. Hi Walter, check your camera LCD screen they are usually quite accurate. See if you can compare it with someone who has the same. Then also don’t forget about looking at the Histogram as this will tell you the actual exposure and you can compare what it reads compared to what you are seeing on the camera screen. Finally find someone who has a high quality calibrated monitor like an Eizo, NEC or Asus and see how your images look on that (RAW files) and then adjust your camera screen to match.

  4. Just wanted to ask, when you take the photo of the black training shoe, that was underexposed, that was not a light meter result, that was the result of the previous light settings that you manually set with the Broncolor app. The very first light meter reading you took of the dummy was, about a stop over exposed (to my eyes) and I suspect if you’d taken another light meter reading of the training show the light meter would have given that same reading hence the shoe would have been perfectly exposed in the instance of the shoe. Or have I missed something here?

    1. Hi Nigel, a light meter only measures the light falling on it. If the light is falling on a black cat against a black wall then those subjects will absorb a lot of light as that is the nature of most black materials. If the light is falling on a white cat on a white wall then those objects will reflect much more light. The light meter would give you the same reading for both because you are metering the light not the subject. As such and depending on the latitude of your camera one subject may look over exposed and one may look underexposed because light meters make the assumption that your subject is a mid neutral grey (that’s how they are programmed). This becomes further complicated if you are using backlighting where the lighting is meant to reflect of skin as some form of rim lighting. A light meter will have no idea what level of rim lighting you want to achieve. And that is the key takeaway from this in that the photographer should have an initial internal visual in their mind of how they want the picture to look. If they do, then it should be very easy to look at the results and adjust them to then match that pre-visualisation and therefore not become to formulaic in the process.

      1. I understand most of what you say above. I guess I got a tad confused as when you took a photo of the shoe it was based on what you’d dialled in, not a flash meter reading, but everything you say makes perfect scientific sense. On a final note, would the flash readings (for a white cat in the snow or black cat against black background) have not been considerably more accurate if the reading was taken in reflective mode instead of incident – especially ‘spot metering’ in reflective mode on the Minolta?

        I used a light meter many years ago, back in the days of my Hasselblad 500CM and Nikon F3 equipment. Having just got back into photography having been away from it for 20 years I’m now half and half regarding light meters. The Canon 5D MK4 I bought has the histogram etc, and I also tether to my MacBook into Capture One, also with histogram, but I still like to take a quick reading with my flash meter simply because I don’t like to have my CF card riddled with too many test shots, that’s about the only reason at the moment. I guess, like you, I’ll find that I use my flash meter less and less, in time.

        1. Hi Nigel, yes all correct and on the reflective mode instead of incident mode, however the more you do it with a test shot then the faster I find you memorise a starting point. For example I start most of my setups at f11 and the flash on mid power and then it’s up or down on the flash from there. But I do waste a fair bit of time testing one light at a time to see what each one is doing independently when I need to be super critical.

          1. Makes sense, Karl. I’ve been out of photography for many years, just got back into it again a few months ago. I guess once I have a permanent studio I’ll get to the point where I’ll be able to set the power outputs of the lights and camera settings and be within an f-stop (or there abouts) without taking a reading.

            Totally loving the site and the superb – incredibly educational and entertaining – video tutorials. Great value and well worth the money.

            Keep up the brilliant work.

          2. Thank you Nigel, and of course if you have any further questions please don’t hesitate to leave them in any of the video comments sections.

  5. Just reading the titles of each chapter I’m getting really excited about how many questions are about to be answered!

  6. After watching these and portrait lightning courses I try to replicate a few of them. I find a model, and makeup artist and did portrait shooting. Only for the first test shot, I used a light meter. Then I decided not to. So what happens is that I pay way more attention to creativity and how light falling on the model then I did it with a light meter. It is more freedom in creativity for sure. Thank you for explaining it so well Karl.

  7. wow

  8. Hi,
    Very good videos you make and totally agree with what you say in this video. But Light Meter also has some advantages, I work in periods in schools and kindergarten as a photographer and I take much group photos of up to 100 people and portraits. It’s very rare i work in the same environment, some days I work in big gymsal, the following day in a small room, or the roof is very low. The exposure should be the same every time, so I can not see how this work without a light measuring. Especially with large group images ranging from 10- 100 people.

  9. Hi Carl,

    Great stuff indeed. One question: I see you adjusting either the aperture or the flash power. Why is it that you never talk about adjusting shutter speed to correct under / overexposure?

    Cheers,
    Jorge

    1. Hi Jorge, you either haven’t watch chapter 5 or you need to watch it again! Then you can ask me again if necessary but I suspect you won’t need to 🙂

  10. Thanks Karl. Today I was buy new light meter around 200$, but after this video you change my mind.
    Thanks again the real man.

  11. Hi Karl, the light meter is still useful for natural light especially when you have to grab a shot,if the camera is in the same light as the subject then it depends where you place your exposure for the reflective meter to be of any use,ie a Bride and Groom and the Photographer all in the same light,the lightmeter will read the ambient but if you use the inbuilt meter then you need a neutral tone to meter .Great tuition though really the lightmeter is redundant for studio work but for natural light it still has a place in my bag. Thanks Rob

  12. Good day Karl, please may I know how you use your Minolta light meter to trigger your flash? I know that there’s a place and time for the light meter, you don’t just throw it completely out the window if I understand you.

    So please I’ll like to know how you trigger that flash with the light meter because I do have something like that.

    Thanks.

    1. Hi Sunday, you need to run a coaxial cable from the Minolta light meter to the flash sync cable port on your trigger or on your flash. Alternatively you can have someone else press the trigger button on the flash while the meter ‘waits’ for the flash to fire.

      1. Thanks, Karl, keep up the good work, I know we can never agree on everything but we should on most things. You’re still one of my favourite teachers anyday, anytime.

  13. My first lecture at your website and thanks a lot for clearing something this important. I am not against Light Meters, I think they are an important piece of technology, however I would rather focus on the creative aspect of studio photography and trust my vision and understand light instead. Thank you for clearing this as I was the only one not using a light meter at school because of the exact same reason:).

  14. Hi Karl, love this video, I’m in my second year of a photography course, they teach you to use light meters and we can’t tether either, my problem is that I naturally want to work in the way you have explained in the video, quite often I get into the studio , set up, start taking photos, check them on the mac then adjust where needed, then I remember I have to use the light meter so I can tell the tutor what settings I used, nearly all my portrait photos come out so much better when I don’t used one, the college I attend is very well respected regarding the photography course and the tutors certainly know their stuff, I’m have an amazing time there, just can’t wait to start out doing it my . Thanks. P’s looks like I might just sell my sekonic x

    1. Hi Mandy, I’d question the tutors if they are not open to the idea of ‘vision’ above ‘artificial automation’.

  15. Hi Karl this was a great video. I started a few years using a light meter but I quickly put is away and never used it since.

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