Introduction and Understanding Light

Before you can work effectively with studio lighting, you have to understand light itself.

This opening chapter of our Lighting Theory and Equipment course covers the fundamentals of light, equipping you with the knowledge you need to work confidently with studio lighting.

In a series of easy-to-follow visual demonstrations, Karl takes you through the practicalities of light, exploring the effect hard and soft light has on shadows, texture and three-dimensionality. He also shows you how to achieve precise control over reflections, shadows and highlights.

Karl’s explanation and practical demonstration of the inverse square law, as well as of the colour spectrum of light, will equip you with crucial knowledge that will serve you throughout your career as a photographer.

In this photography class:

  • 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
  • Colour spectrum of light

Questions or comments? Please post them below.


  1. hi karl, when you mention studio flash in term of good spectrum light do you mean just strobes or does sppedlite include too? i’m using godox tt685 and i found my images just like you said are lack of color, contrast, and punch.


  2. HI Karl,

    Am I right in saying that if you use the small soft box and shoot once closer to the subject and once further away from the subject without changing size of soft box, that the closer shot will have darker shadows. and the further shot will be more diffused? But what will be the difference on the background?

    1. Because of the inverse square law, both the background and the subject will be lit more evenly because the falloff of light decreases as it gets further away. If you put the softbox close to the subject, the background is going to be darker than if you put it further away. But there are more factors that would affect, such as distance between subject and background

    2. piotrczechowski

      Bigger light source = softer shadows
      Smaller light source = harder shadows


      Closer light to subject = bigger light source = softer shadows

      Further light to subject = smaller light source = harder shadows

      Closer light to subject = darker background
      Further light to subject = lighter bacground

      1. Hi, yes all of those statements are correct if you were shooting in space or if you were shooting in a black studio. But when shooting in a white studio things are affected a little differently due to bounce of light and this means that a further light source will result in lower contrast shadows due to the bounce of light from white walls and the inverse square law. Please watch this class too:

  3. hello Karl
    Thank you for a clear description of concepts ,i just love it all the points n so much clear
    i have a dobut if we use florscent light ,like we may not have flash light or extra light in any situation incase , will in built flash in the camera will help with spectrum , will it get better .

    1. Hi thank you. Yes on camera flash will help clean up the spectrum but if you can should bounce on camera flash off of a white ceiling or white panel to spread the light better.

  4. Hi Karl,

    I just finished watching the “Introduction to Photography” series and I really liked the pdf. The pdf is an immense help to go back and brush up on a few things.

    I started watching Lighting courses, “Lighting Theory and Equipment”. Is there a similar kind of pdf created for each series of courses? I really would like to have all the information in the videos as a pdf. It will help a lot to go back and review.

  5. Hello Karl,

    I just signed up and watched this video. Thank you for a clear description of concepts that I have half understood over the years but never quite completely grasp. Your examples were excellent. I was especially helped by the explanation of Inverse Square Law. That one helped me better understand how moving the light closer and further away and the size of the light affects the result.

    I now also finally understand why I have stayed away from fluorescent lighting and struggled with results when I had to work with it. The difference in the vibrancy of the colors was stark and obvious they way you showed it.


  6. Hello Karl, first of all thank you for making the course so easy to learn and to understand all this info.
    second, i wanted to ask you, what’s the best material to use for a scrim??

    1. Hi, either LEE 216 or LEE 400 lux, both will give similar results but the 400LUX is a bit tougher but I think more expensive. See the chapter in the product section about making your own scrims.

  7. Hi in the module introduction and understanding of light, id like to know if using always on lighting or speedlights are superior, especially for someone still learning. I saw how beneficial it was to have the lights on to look at the shadows, but i am confused as when he took the pictures it seems as though they never went off. He said that the light on was not in the shot, but I never saw it go off and back on again. Also I have a couple of square soft boxes already that i use with speedlites (lastolight). i will buy a different light source if necessary (currently using cannon 600-EX-RT Speedlites) even though I dont want to, but I just want to master using studio lighting. I think it is so cool. I have been trying to use LED Daylight lights in the room, but always felt that I needed to turn them off before taking the picture. This is hard in night situations LOL. I shutter to ask what a decent setup for lighting is going to cost me. I do have 4 stands, 4 speedlites, and 2 soft boxes. I am using mostly a Canon 5DSR and have a 5D Mark III as a backup

    1. Hi, the point light source was a modelling lamp from inside a studio flash (the studio flash tube can also be a point light source). An LED can be a good point light source but often they are not bright enough for most types of photography. You will learn more about this as you watch more of the classes.

  8. Hello Karl

    if I take a photo outside when it is cloudy 9000 kelvins and then I adjust it in the post-production in the photoshop to 5600 kelvins, the result will appear as if at the full spectrum of color ..?

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