01. Introduction and understanding light

To truly understand working with studio lighting you first have to understand light. This opening chapter of our “Lighting Theory and Equipment” course covers the fundaments of light, equipping you with the knowledge you need to confidently work with studio light.

Through a number of visual demonstrations Karl demonstrates the practicalities of light, exploring the effect hard and soft light has on shadows, texture and three dimensionality and shows you how to achieve exact control over reflections, shadows and highlights.

Karl also provides a complete explanation, along with further practical demonstrations, of the inverse square law and color spectrum of light.

In this photography class we cover the following:

  • Different light sources and their effects
  • Hard light vs soft light
  • Careful control of light and shadows
  • Using reflectors and negative fill
  • Revealing texture
  • Inverse square law
  • Color spectrum of light

NOTE: This photography class is available with English subtitles.


  1. Hi Karl, Karl here, my girlfriend and I are photographers in Northern Arizona. I am in Flagstaff and she is in Jerome. We do fashion workshops every month and just wanted to get our skill level back up.

    Thank you for this course, great refresher for me and a wealth of knowledge for her.

    Looking forward to what is coming our way.

  2. Dear Karl,
    It’s been approximately 4.5 yrs that I have been learning photography in bits & pieces and tried almost all platforms (online & offline). But the fundamentals of real photography had been evading me and the it was to me as if the jigsaw puzzle was missing the chips. I can’t thank you enough for such a wonderful explanation of fundamentals of light and feel that my search for a true mentor ends at you. I am sure all my doubts & queries will get sorted with your course.

  3. I’m confused. I get the inverse square law and I understand the concept behind it. However, in his video on the law, Joe Edelman says “light CLOSE for sharper shadows bigger catchlights and darker backgrounds”. I know Joe is a great photographer but this contradicts with what is said here – so I must be misunderstanding something ‘cos I know both he and you are correct. I thought with the light closer its size relative to the subject increased which makes shadows SOFTER because of light wrap around”.
    I don’t understand how for a GIVEN fixed size light source the shadows get sharper as you move the light closer. Please help :/

    1. Hi Matthew, please watch this again. A closer light is a bigger light and therefore softer (softer shadows). But the closer light to the subject then it also has a quicker fall off in intensity which means contrast will increase and background will be darker as demonstrated in this video.

  4. Hi Karl, I just joined and love your videos. Yes, clarity is certainly your mantra, which I really appreciate. At around 16 minutes you described negative fill and the way the black reflector was blocking the reflected light from the wall background and from the table; thereby darkening the shadows on the chair. Do you think the black reflector was also bouncing a “black” light onto the shadows that helped to increase the density of the shadows on the chair…much like a gold reflector would bounce gold light as you mentioned later? If so, it would be interesting to devise a test that would demonstrate how much of the shadow’s darkening was caused by the blocked light and how much was caused by the bounced black light. A regression analysis of sorts. I look forward to watching more videos. I loved the paint splashes on the basketball, very creative indeed.

    1. Hi Gregg, thank you for your kind comments. Based on the physics of light there can’t be black light, essentially what is happening is that the black flag is doing two things, 1. it is blocking light from the white wall and 2. it is absorbing light and not allowing it to escape from the black card. A good example of this is the same black card held in sunlight on a cold winters day, it would become hotter than a white card as it is absorbing the energy of the light especially in the infrared wavelengths. A black card is not however truly black and it will reflect some light but this will be minimal and simply is a reflection of light but not black light. There is a nano material that absorbs 99.9% of all light that hits it and to look at it is very bizzare as it is the blackest thing you’ve seen. The only other blacker object would be a black hole and in such cases no light can be reflected or escape as the gravitational field is so strong that it holds light in.

    1. Hi you can calibrate most monitors with a calibrator and the right software. Check on X-rites website for compatibility.

  5. hi Karl, I have a sony a 6000 with a strobe wistro AD600BM no modifier, when I shoot a RAW image and configure the camera to DAYLIGTH and a grey card in the image as reference, in capture one, when I put the pick white balance tool over the grey card in the image it show like 80 87 109 RGB with kelvin 5,528 , the when I click over the grey card to have let say 87 87 88 RGB but the kelvin goes to 7,667 , why is that ? , I would expect to have a grey card measure same values of RGB when it is shooting as DAYLIGHT…. because it is supposed the strobe is output around 5600 kelvin color temperature

    1. Hi, then your strobe is not putting out pure daylight at 5600K, or you have your shutter speed set too low and you have light pollution from elsewhere in the picture.

  6. Omg! Your education is the best I’ve ever seen so far. So much information in one place and everything is so organized. Thank you, Karl for sharing your knowledge with us 🙂

  7. Explained the complex subject with such an ease and really helpful to all the amateur photographers like me. Thanks a lot Karl.

  8. I wasn’t sure what’s the difference between soft and diffused light…
    Didn’t understand light at all.
    I’m a chef, not long ago started to photograph food.
    This course is just what I’ve been dreaming of!
    Now I’m starting to understand light!

  9. Hello Taylor;

    Juan, thx for this movie.. Question I work at night; & I used flashlights when I light painting. As up today I am a try and error person, but sound like I can used this and make more used of the time.

    I assume that is I think as my flashlights as a small hard light, and moon as a big source. Am I correct in this.

  10. Hi Karl, Im from Jordan, I’m a hasselblad user, to be honest after this video i found out how wrong i was with colors and light. OMG this helped me to understand what is light… thank you so much

    1. Thank you Omar, this is also one of my favourite tutorials on our platform as it brings a new understanding to many people that is very very important before you can move forward with photography.

      1. I’m pretty sure that my photography skills will increase through your professional videos, I’m so glad to be under the name of Karl’s student, I’ve been watching your videos on youtube since 2012 when i bought my first hasselblad camera, It was H1.

  11. I’ve started studio photography as a hobby a bit more than 2 years ago, don’t get me wrong, I had some brilliant pictures but I just realised I knew nothing about lighting. You are an excellent teacher Karl (if I can understand it, you are!) and this was the best spent money for 2018 for me. Thank you!

  12. This was so informative and easy to follow! As a beginner in photography, the visual demonstrations definitely helped put things into perspective.

  13. Absolutely brilliant Karl! You are such a great teacher and explain things so clearly – thank you. I have just watched this AFTER receiving a light yesterday. It’s a ‘work light’ 200w with a 6000k white daylight but I am now thinking it will be missing some of the colour spectrum – eek! I am on a tight budget and this light was £20 and I am hoping it will help get me through the Winter in the UK while shooting food indoors when the weather is terrible outside or when the light disappears at 4pm! I will apply all you teach me and hope the light is sufficient. I can’t stop watching your videos – all of them so great – thank you!

  14. I’m so glad sigh up in this course. Now I know why my photographs doesn’t look right in studio. Thank you so much!

  15. Very useful information, I am very satisfied with the content. I was wondering if you could make the chart available for download? In any case, amazing lesson.

    Thank you for your, and your team hard work!

  16. Just when you think you understanding basic concepts you see something like this and it opens your eyes to how much you really do not know. Incredible job, so clear and concise.

  17. It’s very impressive how clear your teaching is. Many things we think we know you make clear what it is. I’m glad I subscribed.

  18. That was AMAZING! I took about 3 hours to watch the video, I wanted to grab every single peace of knowledge and I still feel I need to watch this video in a couple of months.

  19. I can learn by first understanding foundations. This is the o my way I can really take advantage of a subject and I appreciate you teach in a way foundations are clearly understood. Nice job !

  20. Absolutely amazing! Exactly what I was looking for in regards to learning about light. Thank you so much Karl, you’re a master!!

  21. Oh my God! This is so amazing. I´m so glad to be here and be part of this Masterclass. Thanks a lot Karl!!

  22. Hi Karl.

    Just signed up this week and really enjoyed my first lesson. Presently learning Studio work and I can’t wait to delve into the rest of the tutorials.

    Many Thanks


  23. The part that helped me here is using two different light size and moving them closer and future away, the light fall off and the dept of the shadows reflected off the subjects help me to understand the light degradation effect a lot …… thanks.

  24. I am sure this is my fault and I feel stupid posting this but I just joined today and all none of the videos will play or even give me an option to play them. I am using chrome as a browser if that helps.

  25. Regarding 50:30
    So from what I understand, when it comes to photography… fluorescent lighting is the worst kind of lighting I could use since it does not have the full spectrum of colors.
    And the other lights besides daylight are not perfect but we can make them work.

    And the flash from flashguns or studio lights do give a good spectrum.

    Am I correct?

    1. Hi Jacques, yes except the light from flash is basically exactly the same as daylight and so are HMI continuous lights.

  26. Wow, as someone currently working on a degree in photography this has been the best explanation of light I have ever seen. I feel I have a much better understanding now of how light works and what to consider when on a shoot.

    Thank you Karl.

  27. This is definitely a very informative, and hugely valuable, lesson in light. I certainly learned a lot. In terms of the color spectrum, and differences between different types and quality levels of light sources, it calls into question the choice of which flashes or continuous lights to purchase. I’ve heard, several times, that light is light and you don’t need to buy expensive products. Not too sure that statement holds water at this point. Also, if you are using a light source that is lacking the full color spectrum and you end up with an image in which the colors are just off, and not very vibrant, how much can you rescue it in post processing?


    1. Hi Chris, If you are missing part of the spectrum from the light source you can’t rescue it in post. Nearly all studio flashes will give you a clean light, as will HMI lighting (very expensive) or LED’s with a CRI of 95 or above, however my opinion is that LED is too limited in terms of modifying the light.

  28. Thank You. I watched the first video last night and I learned a lot about light. This is amazing training and well worth the investment and then some. I have some of your DVDs that were purchased a few years ago. They have become great reference material. Thank you Karl amazing training material and you make it easy to understand !

  29. Hi Karl, I have a quick question. Whenever I see continuous lighting kits for sale they’re either LED or Flourescent bulbs, why? Are the fluorescent ones special or just a ripoff? I see them all the time on Adorama, B&H, and Amazon.

    Thanks for your videos. I found you through fstoppers.com and this is the first time I actually feel confident about learning studio lighting.

    1. Hi Rashonda, personally I wouldn’t use LED or fluorescent as I don’t think they are properly full spectrum. They have improved but then they are also not as bright as flash or have the ability to add as many modifier options.

  30. Karl, I’m so excited to sign up for KT Education. 6 yrs ago when I purchased my first DLSR camera. Those first few years I purchased numerous of your training DVD. Over the last several months I’ve felt something was missing and I not where I want to be in my photography career. I felt a serious need to turn back to you and training.

    Thanks for continuing to be a great teacher and an inspiration to so many!!!

  31. With crystal clear explanations and simple, practical illustrations, this tutorial alone was worth a years subscription! Having a deeper understanding of light has strengthened my foundation knowledge dramatically. I had not appreciated the discontinuous nature of fluorescent light. This clearly explains why my images taken under this light are impossible to correct. I can’t imagine what I will know tomorrow.

  32. It was amazing, Specially the spectrum charts, now I have much better understanding of the different light sources.

    Thank you

  33. Just joined and this was my first video. While I had some knowledge, this was the most complete and informative material I have seen. Excellent detailed descriptions.
    Thank you!

  34. Hello!
    Just joined to give it a try!

    I wanna ask a question relating to the inverse square law you were talking about in this video.
    I know you were using a artificial light but I suppose the law works the same for any kind of light. So what if few people taking a shot next to window and they are standing side by side. Will the exposure on everyone looks almost identical? since I thought window lights should come from far far away . So theoretically it is not a problem when we shoot or is it?

    1. Hi Yiqing, it depends on the light coming through the window, for the inverse square law to be strictly accurate the light must be coming from a point light source (not a big light source) so if it was direct sunlight then in theory yes but if it was from cloud or the sky it would be different but it would certainly be more even in exposure than from a softbox.

  35. Hello Mr.Karl.. I’m from Greece.. im huppy for this site that you created, to teach us about the photography…you speek clear and understand the most, because my english its not so good… thank you very much…

  36. Hay Mr. Karl this is owsm really owsm n thanx for this tutorial
    spatially ur way of explaining is too good i m fron india i m ltl bit slow in english but in the way u explain i get all evry point easy way thanx for this.

  37. Thanks for this information. Would have loved to have seen correction gels or filters being used to see their effectiveness on the fluorescent lighting setup. How effective are the screw on correction filters that were used in film when shooting in fluorescent lighting.


    1. Hi Edmond, unfortunately they are no different to trying to correct this in post-production. What you have to keep in mind is that if part of the spectrum is missing then it’s missing and there is no way to bring it back so correction gels won’t help with that but they can help in correcting incandescent lighting as this has full spectrum it’s just biased towards red so a correction gel would be fine but not for standard fluorescents.

  38. I believed I was quite experienced on basic light understanding, however, I learned some new items. Items I new, was very well described, and gave a better understanding, as I had before.

  39. Hi, I am new here and I feel so lucky to find this rich course, will definitely recommend it to all my friends, thanks a lot Karl for this valuable master pieces! 🙂

  40. The moment I decided to buy my Siros L’s and therefore get introduced to you and Urs by first making me watch Broncolor “how to’s” and then allowing me to watch your 40 free videos for Broncolor users was a real blessing. These made a decision to join KTE a no-brainer.

    Hats off, Karl, hats off. I just love every single aspect of what you do here, starting from your accent which is so easy to be understood by a foreigner, through cosmic amount of your knowledge and experience and the ability of passing these to the viewers in such an organized and attractive way. As my predecessors have already noticed – I thought I knew something about light. Now, after just 1 hour of your lecture not only I know twice as much but everything seems to have finally found proper drawers in the cupboard of my mind. Just amazing! And considering that all this magic happens for $14 a month – you have got a loyal, long-term subscriber who will keep spreading the word about the quality of your educational resources.

    Thank you and the whole team. Now I am going back to watching the next chapters.

    1. Thank you very much for such a testimonial Miroslaw and joining KTE. We look forward to bringing you more great stuff in the coming year. Please tell your photography friends and we can make this community even bigger and better!

  41. I joined a Facebook group and I posted asking questions about the inverse square law and the angles of incidence refraction and reflection, and no joke, NO ONE knew what I was talking about and told me I was being to technical. I believed maybe I was until you heard you say “photography is all about KNOWLEDGE of light” I have since then joined your group and continued my quest to master light! Thank you for being so in depth and precise during your teachings!

  42. Just to clear the confusion, in the part where you review colour radius for fluorescent light – how come you say it’s a peak of “green” but I see yellow? Am I missing something here?

    1. Hi Dominick, it is green on the graph. On the camera at 47mins 22sec you can see it is green I think it is just the other camera is higher in exposure making it look yellow.

    1. Thanks Peter, i’m afraid not, you’ll have to watch it again and write them down – good learning practise though 🙂

  43. Well I’ve just signed up and after just this one lesson I’m so pleased I have. I honestly cannot believe the range of courses available. Thanks Karl, I’m sure that I will pick up a lot of information on how to improve my skills.

  44. just perfect! every episode that i am watching, i will be more satisfy for my membership, it worth every single penny… Karl has a great energy (beside his attractive English accent), great course-programming (to cover all students’ need to know) and great capability of demonstrating all topics in Photography, which are absolutely useful for beginners as well as professionals. thank you Karl, thank you team 🙂

  45. I have wanted to travel to your courses in England. But the total cost (course, travel, hotel) has hold me back. I know I still will get more personal instruction attending one of your workshops, but this online course is actually a huge step up in knowledge.

    I would personally thank you for releasing this material for a very resonnable price. I love your detailed explanation.
    And lastly, I’m looking forward to go through all here.

    Regards, Tom, Norway

    1. Thanks Tom. For us to continue to offer great value to all our members then please spread the word. Also don’t forget to check out some of our live shows they have been very well received.

  46. Hi,
    This is my first lecture. I am facing too much buffering issues despite having a good internet connection. How can i resolve this? I am trying to watch this video of 58 minutes since more than an hour but could only see about 38 minutes so far

    1. Hi Muhammad, we are surprised you are having buffering issues as we have tested our video delivery on a number of speeds and services and selected customers also test at different parts of the world. So far there aren’t any real problems reported. The only issues we’ve had are where older slower computers or browsers were being used?

  47. I’ve bought a lot of video / online tutorials recently covering a vast array of topics from and have spent in excess of about £600 and not one of them, even if specifically covering studio lighting have covered the inverse square law. Not once. They’ve mentioned it and skipped past it. I now know what it is 🙂

    Great tutorial, great pace, easy explanation – you dumb it down enough for all levels and not too much to be patronising. Very well done and thank you!

    1. Thanks again James, we hear that a lot and we’ve tried to make our platform as affordable as possible so please spread the word! 🙂

  48. Amazing explanation about light! its remind me when i was in college. Each day of learning is a huge progress improving my photos. Thanks

  49. Very well explained .. It inspired me to get better at my studio lightning and I learned a lot of what I didn’t pay attention before.
    Only one question : when you compared the larger softbox to the smaller one (the large one was far and the smaller one was closer and they looked the same size from the subject’s point of view) in the final result images the right angle was more illuminated and the left one shady ; Was that because of the light source was positioned from the right or did you use another fill light ?

  50. Hi Karl,

    Regarding the images you used in this video (01. Introduction and understanding light), what was your camera WB setting and how did you set it?


  51. Thank you Karl! For the price of a meal you have provided a wealth of knowledge and industry insights which is helping our business. Romba Nanri (Many Thanks in Tamil).

  52. Karl Taylor, you are the best teacher ever! You make it all easy.
    So little money for such a huge amount of information!

    Thank you.

  53. Karl, I am from Brazil and have just joined the community. I admire greatly quality of your job and I look forward to learn more and more from you.

  54. Karl, i joined last week so i could watch your live stream i have 4 of your dvds so was a little apprehensive about spending more money, i was sincerely blown away by the live presentation it was better than anything i could have hoped for i am so happy with the subscription and would recommend this to anyone

    1. Thanks Roger for taking the time to comment, we are of course extremely happy with such feedback. Check out some of the previous live shows too before they expire. We also have more courses and live shows coming on all the time. Enjoy! 🙂

  55. You were the reason I had started doing fashion/portrait photography. Your free youtube videos had inspired me so much to switch to fashion photography and today 4 years down from then, I’m a professional fashion and events photographer based in Abu Dhabi, UAE.
    I still have a lot more to learn and a long way to go and looking forward to getting much more knowledge from your tutorials here.

    Thank you sir,

  56. This was amazing! I knew nothing about the spectrum representation of different types of lights. I’m excited for the rest of these videos!

  57. I’ve never seen anything that comes even close to this video. I was enthralled all the way through, everything, even stuff I thought I knew was explained brilliantly. The hour flew by, in fact it’s the first hour long video I’ve watched all the way through without a break. Thank you Karl, you are giving us value for our $14 many times over.

  58. Great lesson, thought I had a good grasp of light, until today. Your explaintion was bang on. Made it all make way more sense.

  59. Hello, Karl. I’ve been watching your work for several years. You are a great photographer and a brilliant instructor. Probably the best (as in Karl sberg commercial 🙂 ). Very well explained. Thank you very much.

  60. August 6, 2017
    J.jean-Claude Davilmar
    This is one of the best course I ever seen yet simple and clear to understand
    Thank you.

  61. I’ve been learning from Karl since the first free you tube video I viewed 7 years ago…By far the most articulate and most intuitive instructor, EVER! Your Advertising DVD took my photography to another level and with that, my confidence as well. You are an inspiration man and I love your passion! They call Johannes Vermeer Thomas and Kinkade the masters of light in the world of painting but let me tell you…you’ve got a pretty strong grip on the concept yourself.

    Thanks for the years of training and the future growth through your new
    Karl Taylor ED site.


  62. This will be the last video you will ever need to watch about understanding light. Just brilliant Karl. This is the first time anybody has really managed to convey the fundamental principles of light to me so well. Thank you thank you SO much. I can hardly wait to see where your other tutorials are going to take my photography!!

  63. Physical prints rely on reflected light to view and the ambient light can alter their appearance significantly. Photographs displayed on screens are back lit and shadows will often be brighter. This can really affect how people perceive the final photograph

  64. hey Carl, this amount of information for the price of $14 per month, in my opinion is cheap and usefull… ill try to recommend my friend for this website…

  65. Thanks Karl, that was really good, I loved your DVD I got most of them some years back. This Introduction and understanding light was really good too 😀 can’t wait for your live show in 2 days. Thanks you for all your help the years. 😀

  66. What a gorgeous and functional studio! I particularly enjoyed the part about the scrims and the gradation of light descriptions.

  67. Fantastic introduction Karl. You always seem to get the level just right. Looking forward to the rest of the course.

  68. Awesome intro!! I wish there was a way to bookmark where u are during the course so I could switch devices. Going from office to bedroom ect.

  69. Hey Karl

    I’ve enjoyed this Intro to light lesson – I thought the courses should have be available to download and watch offline too. But I am very happy that you have not made it so…simply because I made the time to focus on the lesson, without any distractions – if you cant make time it will not make a difference; if you not going to do it now – it never gets done.
    I like your work ethic, and I’m looking forward to building upon each lesson.

  70. Great stuff. Really enjoying these videos. One question – why is it that when recording video we can use fluorescent lighting without affect?

    1. Hi James, thanks for joining us. There is actually still a detrimental affect to video too with standard fluorescent, it’s OK with balanced kiniflo but not otherwise. There appears to be less degradation to the image because the image is moving and the motion distracts from the irregularities. If you freeze a frame of video filmed solely under standard fluorescent tubes then you would notice problems with skin tones even if you white balance. Video is also often more forgiving because we are used to seeing it in video but I can assure you if you extracted a frame of video and compared it to a frame taken from a sequence filmed under HMI lights or daylight you would notice a significant difference.

  71. Is there a way to download the videos so i can watch them offline ? On your other page you had this option and it was great =)

  72. Fascinating! As an amateur astronomer I understood about the inverse square law of light but I have never heard it explained so eloquently. That was awesome Karl.

  73. I never thought about reflected light let alone how to manage it until I watched this and it does all make sense, thank you.

  74. Awesome lighting introduction Karl! So looking forward to the other training material. Have always been impressed and learned a lot form your training DVD’s.

  75. Got 3 of your DVDs Karl and had the pleasure of meeting you at the NEC. Looking forward to learning from you. Wayne

  76. amazing, and it is only 14$ , you will never find that amount of information at this cost.
    I wish if the next videos play automatically, without clicking on it.

  77. I thought I understood light and now that I’ve watch this, I have better understanding of light. Awesome.

    1. Glad to hear it Patrick, we will be doing more on this subject in our first live show. Check the live show page for details.

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