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. Gary Stasiuk

    These lighting classes are great. So far I know most of your presentation but you literally go through everything in great detail so any vacant holes are filled. Such a great resource. I have a strobe meter which I haven’t used since rekindling my studio lights and going digital. I realized, while watching this that I should sell that thing before it is completely worthless. Enjoying your content and most importantly, learning.

  2. Hi Karl, thank you so much for these classes – they are fantastic.

    I shoot mostly digital, but I’ve recently been more curious about film photography. I’m wondering if you would recommend getting your strobes dialed in with a digital camera and then adjusting the settings to match on your film camera to achieve the same exposure (as opposed to using a light meter)?

    1. Hi Casey, that’s one way of doing it but film doesn’t always come in the same as digital. So for example you could be shooting 100ISO EKTACHROME and 100ISO on digital but they’d look differerent because of latitude of the shadows/highlights and even the exposure may vary. If you’re going to shoot film it is best to use a lightmeter and run tests on the film and lights and light-meter measurements and note down the results for future reference. Back when we used to shoot film we also had polaroid backs for the medium and large format cameras, so we’d swap backs and shoot polaroid tests until in the ballpark. The polaroids were pretty well balanced to match the film but not 100% either. You have about 1-2 stops latitude of error with negative film and about 1/4 stop latitude of with transparency film. Meaning you can still get a good print out of negative film if your exposure is a little off but not so much with transparency film.

      1. Thanks so much for your thoughtful reply Karl. That’s helpful to keep in mind – so much more to explore with film as well!

  3. These videos are absolutely brilliant and worth every penny, I’ve learnt loads already. I first got into landscape photography a few years back and spent most of the time trying to just capture natural light, on the few occasions where I actually needed to use lighting I was pretty much clueless!! I was sceptical about clicking on this video as the thought of using a light meter also seems odd to me, though after the first few minutes you’ve grabbed my interest again!! Thanks so much, and keep up the great work!!

    John

  4. Hi Karl,

    Many thanks for your amazing classes, I am learnings lots from you and today, after this chapter I decided not to buy a light meter, thanks for the advise. I am still a beginner and I am having problems with the settings of the camera to use the lights. In this chapter, you didn’t say anything about shutter speed and that is one of my main problems. Did you use HSS?

  6. Hi Karl, good explanation.

    I suppose to use a light meter is like using TTL in the flash. You can use it as a start point and after it you change the parameters to obtain the result you want.

    Regards from Spain.

  7. Not used a flash meter for a long time but when I did – 1980s/90s, the advice was around direct or reflected meter readings. Would a flash meter work more accurately if it measured reflected light in the way the camera does?

    1. Hi Matthew, no not really although flash meters can measure incident or reflected, the reflected setting is still based on the same 18% grey reflectivity as camera light meters so it will struggle with pure white or dark black objects. The best advice if you wish to use a light meter is simply use it to get you in the ball park and then put it down and focus on using your eyes and creative vision to make the rest of the decisions.

  8. Hi Karl,

    Really loving all your classes and learning so much every day!

    I do believe that sometimes too much technology can hinder your creativity. My question for this class is, does this mean we should not reply too much on the light meter in the camera as well? I just started using manual mode after taking your course, and when I set the aperture and don’t use the light meter, I really have no idea what shutter speed to use, so I usually read the meter, and take a test shot first. Sometimes even when the meter shows perfect exposure, the photo is actually over or underexposed, so I will then adjust the shutter speed regardless of what the meter says, and I believe after shooting manual for a while I will be more familiar with what shutter speed to use even without reading the light meter. I wonder is this is the right way? Thank you!

    1. Hi Miya, glad you are enjoying the courses. Yes it’s absolutely fine to use the camera’s built in light meter to get you in the ballpark and then work it out from there. Like you say at some point in the future you probably won’t need it as you’ll start guessing what it needs to be and as you also said you’ll often find it’s not accurate anyway so simply use it as a guide and nothing more.

  9. derrick_connell

    Terrific.

    I joined today, and this was my first video. I have a light meter and have been feeling guilty about owning it and not using it. I have been using my own eye and aperture, and this video has reinforced my choice.

    Time to head back to the camera store and sell my light meter!

    I am very excited about the possibility of creating images similar to the examples you provided in this module. The paint photo is stunning – and something to aspire to.

  10. Agree with the points–only thing is that I shoot with 8×10 Large Format, and by virtue of using film for the kind of work that I do, a light meter is necessary.

    On that note, what kind of tips in terms of measuring/metering light creatively can you share given that I am shooting table top still life.

    Appreciate it, and +1 to creative intent at the forefront of making decisions.

  12. Of course, I agree a light meter is imprecise, which is why I’ve always preferred using a spot meter (and I still do as I mostly use B&W film), but I disagree with the statement that it gives you the “wrong” exposure; just like a spot meter, it gives you the aperture, for the iso, time selected, and current flash power/ambient light, in order to correctly expose a middle gray card, nothing more, nothing less. Once you understand that, how all these parameters relate to one another, and understand the zone system, you can make all the creative decisions you want, and combine multiple readings to evaluate contrasts, these decisions have never been taken away from you. And I have to say this is one of my great pleasures in photography, but I certainly am awfully old fashioned 😉

    But yes, with modern digital cameras, thanks to histograms, light meters are unnecessary, there’s no debate here, and shooting tethered is even better when one can.

  13. “You need to think of lighting as a column control on your music system…turn the power up and it gets louder, turnout down it gets quieter….” BOOM!!! #moneysworth #Brilliant
    LOVE this course

  14. I’ve never had a light meter but for some reason decided this week that I was missing out on something.

    So of course I went online and ordered one.

    I’m sure I’ve watched this video before but thankfully at some point today, I happened upon it again and it reminded me that I don’t need a blasted light meter.

    Was able to cancel before it shipped and saved myself a couple hundreds which can now go towards some other gear …… 🙂

    1. Hi Simon, if you mean the 30×120 softbox pointing at Stiffanies neck and side of her head, then yes that is flash as well.

  16. 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.

  17. 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

  18. 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.

  19. 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.

            1. 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.

  21. 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.

  23. 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.

  24. 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 🙂

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

  26. 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

  27. 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.

  28. 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:).

  29. 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’.

  30. 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.

Leave a Comment