I do enjoy watching other photographers and camera enthusiasts on such channels on YouTube. As you may conquer, many are informative while being entertaining at the same time. It always impresses me at the amount of knowledge people have while reminding me the little I have. I can’t be too hard on myself after all this photographer is self taught. I have come to a point where after years things seem to be making sense. That is having an understanding as regards the behavior of light. Yes! Photography is the capture of light. Photons. Photons of light. The very essence of transfer of information in the Universe. Without light what would exist ?
On this planet certainly we wouldn't. So light is of course ultimately important. To most people I’m sure this subject isn’t one that pops up very often, maybe if a fuse blows and the light goes off perhaps. But generally most wouldn’t give a second thought to the properties of light. It is the most unusual and yet under controlled circumstances a predictable substance. To some people who may look at a portrait shot in a studio, might not realize the subject was lit entirely with artificial light. An electronic manifestation fired from a flash head. A fast burst of ten thousandth of a second or faster. The light's reaction varies in different ways depending on its distance from the subject and its relative size. It seems in some cases it acts like a wave and in others it acts like a particle. As a photographer shooting in a studio we don't need to know the physics behind lights property, but a clear understanding of one aspect would be helpful.
To gain some desired results in a studio, especially a small space like mine, an understanding of light fall off is immensely important. I’m talking about the famous inverse square law. It not only applies to light but to sound and other electromagnetic waves. As photographers, practicing manipulating light using the law is very useful. It gives an opportunity to create a dark or even black background even in a daylight studio. This is a light fall off. Like sound it will only travel so far before it is so dispersed as to have lost its effect. We can soften a person's skin by placing a large relative light source close by. This will make the light react in a way as to give soft gentle light with graduated shadows but also creating a faster fall off of the light.
Without going into the subject here too deep it is one to be studied and practiced. This might sound complicated but with practice and careful positioning of flash heads and the use of control of power, light can work for the photographer in a way like never before. The advent of digital has given new opportunities in light control that film makes more elusive. As you may know I always say to practice your photography. This is by my own admission something I also need to do more often, but it’s true the only way to improve and to keep in touch with equipment is by a continual drive to get better. So in summary a great leap forwards to any photographer especially a flash user is a grasp of light fall off. The inverse square law. For example, a light source is moved twice the distance from the subject so the distance is two times. Simply square the distance two times two equal four. The power output relative to the subject will be a quarter. This is an exact science in physics but in photography it is also allowed for artistic license.
There is like in other creative areas such as painting no hard fast rules, look at light fall off as a tool like any piece of photo gear.