02. Understanding exposure

Getting the balance of light right requires an understanding of exposure, or the “brightness” level of your picture. Your cameras light meter can help you do this but this isn’t the only way to do it.

How can you make these decisions for yourself? In this chapter find out how and why exposure matters as Karl demonstrates how you can control the exposure. He shoots a number of portraits with different shutter speeds and also explains the relationship between aperture and shutter speeds and how you can adjust these to get the best results.

In this photography class we cover the following:

  • What is exposure
  • How to control exposure
  • Aperture: How to control exposure with aperture
  • Shutter speed: How to control exposure with shutter speed
  • ISO: How to control exposure with ISO
  • The relationship between aperture, shutter speed and ISO

To learn more about some of the concepts discussed in this class, take a look at our Photography Quick Start Guide.

If you have any questions about this class, please post them in the comments section below.

NOTE: This course is available with subtitles.


  1. Hi Karl, I’m new in photography but i can tell right I made the right choice for selecting this specific course.
    My question now how do you get the 12 pages PDF reference guide?

  2. How do you know if your image is under or over exposed? asides from wether it ‘looks’ how you want? is there a specific way to tell, for absolute beginners, whether your photo that may look ok to the untrained eye, is actually over or under exposed? thanks

  3. Hi Karl, I am yato from Japan, its so great for me to joint your class. I was taken conventional class in Japan many years ago but wasn’t good enough for me. You teach it so clearly and systematic, so it is so easy for mr to understand. thank you so much.

  4. I’m so excited to take this course. I’ve been very afraid to take the leap and learn photography because i’ve been so overwhelmed with the info available. i found this platform from a facebook photography group. I’d like to have a successful career in photography but i dont know if i have what it takes to start from scratch. i hope that these courses can help build my confidence to do more. any pointers on how i can build my confidence with photoshoots would be well appreciated. 2019 is my year of achieving milestones!

    1. Hi Magdalene, thanks for joining us. Work your way through the modules in order if you can even though it may be tempting to jump around. Then take as much time to practise what you are learning in the classes. Any questions that you have just post them in the comments section below the module, sometimes the questions may be answered in later modules but don’t be afraid to ask. All the best and good luck Karl.

  5. One solution is set the meter to matrix and expose for the highlights isn’t? I still can’t do it properly… But my results are better… Sometimes the subject gets a bit underexposed u can correct on post or just fill in with a speed light… My problem is when the sky gets in the frame … I expose for the sky I can bring the subject back in the post but the color a not that vivid as they suppose

    1. Hi Alexandre, I wouldn’t consider any of the meter settings a solution. As you progress further with photography you will come to realise that the only solution is a decision as to which range of tones YOU decide to capture most accurately and in doing so some may be overexposed and some may be underexposed because cameras cannot capture everything that your eye can see and it cannot be reproduced or displayed in the same way. As an example, imagine that your eyes can see life around you as a 1-100 range, your camera however can only ever see 80 spaces in that range. You can choose to set those 80 spaces from, 10-90 or 1-80, or 20-100. The point is when you work in manual mode as you will learn through this course, you will decide where to place that range based on a creative decision that you will come to learn. No light meter can really ever decide for you what is best, the light meter is just a computer it can only approximate what it thinks it should do.

    1. Hi Chethan, it’s calculated in general terms by the focal length of the lens divide by the diameter of the opening aperture physical size. Essentially though f8 or f11 on one lens should be a similar exposure value to f8 or f11 on another lens.

    1. Hi Joel, the simple answer is when it looks right. A slightly better answer would be when your highlight detail is within reproducible limits and only the very very darkest area of the image is black but the areas of shadow are still perceivable and yet with all this does it still look right.

    1. Hi Marilyn, thank you. Of course if you have any questions just leave them in the comments section below any module.

    1. Hi Brian, different lenses have different maximum apertures. As you progress through this course you will realise there are two other ways to compensate for the exposure other than the aperture; shutter speed and ISO. Give me a shout again at the end of this course if you still have any questions. Regards Karl.

  6. Hey Karl i just bought a nikon D3100 so i’m starting.
    I have one question, when i’m shooting can I trust the light-meter?
    Thanks, Cheers from Paris !

    1. Hi Filipe, you trust it to get your test shots and get you in the ball park and then you look at the results on the screen in combination with the histogram and then make a decision from there in manual mode on where you would like the picture to go. You will learn more on this as you progress through our courses.

  7. Hi Karl, Brand new subscriber to your site and liking what I’ve found so far. I am going to work through all the videos, but is there one that specifically addresses effective use of the histogram to judge exposure? Just getting started so forgive me if the questions seems impatient…:). Regards, RJ

  8. Great video-I cant help thinking that in this tutorial the image that you state is the ‘correct’ exposure to my eyes looks a little bright, whereas the image taken at 1/200 looks a little more moody and natural. What are you deeming a correct exposure here? What you go for as a photographer, the light meter reading or a histogram reading?
    Thanks, Mike

    1. Hi Michael, if i’m not shooting tethered (which is not often in the studio) then i’d look at the histogram in combination with the image on screen, that would allow me to interpret the histogram in correlation with the image. When I shoot tethered then I’m linked to a properly calibrated monitor and can trust what I’m seeing as well as take measurements of RGB values from key points on the image.

  9. Hi Karl, I am kind of brand new in photography, even I have been passionate about it all my life. My question is, how do you know when is the right exposure, is there any way besides having a light meter, does the histogram will help? cause if you use a 1/125 won’t make a big difference but how you will know 1/100 is the right one? hope I explain myself. Thanks

    1. Hi Luz, the look and feel of the picture has a lot do with it. Does it look how you wanted it too? If not why not? What is causing it not to look like that? The second thing is the Historgram that can give you a lot of factual information based on the expected content of the image, you will find more information on Histograms in another module. Cheers Karl.

    2. its more about what you are trying to achieve rather than a set exposure, Karl always just takes a shot, looks at it and then adjusts the exposure to what he wants it to be

  10. Karl, I have been a professional photographer for over 20yrs and this was the best translation of exposure using film camera vs. digital regarding exposure I have every seen! Very well explained! Thank you!

  11. You mention using the in-camera meter as a way to get the exposure right. I often find, though, that taking a picture at the zero point ends up in an overexposure (i.e., with lots of blown highlights), so I’ve been taking my shots slightly “underexposed” (according to the camera), but which have less overblown highlights. Would be interested in your comments on this.

    1. Hi David, I only ever use the camera’s light-meter to get it in the ballpark, after that it’s manual decisions all the way by looking at the preview image and the histogram. Cheers Karl.

    1. Hi Edward you can see the settings for each shot on the back of the camera and in the simulated viewfinder for each shot.

  12. Hi Karl, at one point in the video I see you are using “AI servo mode” on the older DSLR.
    Would that be your preferred choice over “One Shot AF” in this kind of portrait situation?

    1. Hi Dirk, I actually mostly use manual focus as that was what I was use to from the ‘old’ days before digital! Then I’d say I use one shot AF and only servo if the subject is moving towards or away at a manageable speed.

      1. At 0.24 the Tilting movement, what is it for?? Is it focusing center to the eye with “One Shot AF” then move back to the center of the image and take the shot?

        1. Hi Michael, yes although on many modern cameras you can select a focus point off to one side instead. Some now I think even have eye recognition to know where you are looking.

  13. Karl…..you just clear that big mystery on the f-stops and speed for me in 15mins than many many hours on youtube and bloggers. I am SO GLAD I signed up!
    You are a genius!


  14. You are brilliant , i have seen 100ds of hours of toutourals on youtube and this is the clearest of the bacics. thanks Karl.

  15. Karl hi where is the new course you was saying about it I am still new so please let me know how to start thx sr I want to learn from you as much as I can thx teacher.

    1. Hi Gabriel, our newest course is Light Source, you can find it under the portrait tab at the top, if its the latest live show Karl was talking about, you can find that by clicking the live button at the top of the site and then scroll down to the archived shows, hope this helps

  16. Karl, can I please ask you what’s the best practical video camera you would recommend for behind the scene shooting …?

    1. Hi Tony, we use the Sony Rx100 mk3 but there are new models out since. I like this camera because it has great video quality and is quick and easy to get out the bag and has a flip up screen for selfie behind the scenes video too.

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