In a previous article, we looked at some easy ways to start mastering light.
Another important element when taking pictures is the distance between our main light source and our subject.
Sometimes the easy things are not that obvious!
It may happen in our practice to find that despite perfect settings on our camera and a good quality of ambient (or artificial) light, our subject is not conveniently lit.
As you learn photography intuitively, some concepts turn out to be more complex than others! The distance between our subject and the main source of light is, in my opinion, part of this category.
Why is this distance so important for food photography? How does it impact our subject? And why are the physics lessons so boring but useful? ;)
Light follows precise laws
I will not deal long with the inverse square law that applies here, as there are many resources on the Internet.
According to this law, the power of light is inversely proportional to the square of the distance.
In other words, if we double our distance from the light source, we decrease its power by ¼ (and not by half as one might be predisposed to think).
Mathematics guru or not, one thing is certain: the closer we are to our light source, the more light we have available for our scene.
This proximity is created by simply bringing our set closer to the window or light source.
It can be as simple as that.
Exercise: One way to quickly test the impact of this proximity is to bring our subject completely close to the window and then gradually move it away. Observe the intensity of light at different distances. Take pictures if needed to better visualize it!
But what happens when you move the set away from the light source?
By moving our set away from the light source, its intensity decreases drastically and quickly.
This initial fall-off happens very quickly (right after the first meter or so!), then this fall-off slows down the further we get from the light source.
Photographer Rachel Korinek in her e-book "Art of Light" introduces the concept of "available light" which I find very useful to better understand this notion of distance and intensity of light.
In practice : if we are looking for a bright and airy scene, being very close to our source of light will make things easier in most cases.
Note that these rules apply not only horizontally but also vertically. So if our window is located very high above the table, there may be a loss of available light!
In a future article, I will go into this height issue in more detail and also talk about another very important topic - the size of the light source or apparent size!