The Diffused Value is, “The Photographers Reference Standard for Everything!”

Hi and welcome to my blog.  Today I want to continue teaching how to use light meter.  In this post, I am going to step back a little and start at the beginning.  In the last couple of videos, I gave you a taste of the kind of control you can expect if you use a light meter.  Also I started to show you a system of control based on a known reference, called the “diffused value”. That system of control allows you to predict an exact exposure, such as a black or white background, as well as create and reproduce any color you can think of.  The system is invaluable for my photography, but lets step back a little, today.

I will start at the very beginning and explain the foundation of everything in photography, let me rephrase, the foundation with respect to proper exposure.  The key to controlling and maintaining proper exposure is knowing what the proper point of reference is.  So here it is, the point of reference for proper exposure is 18% grey (often called by many names).  Some of the names are middle value, middle grey, or ”The Diffused Value”.  The diffused value is the area in which we see the true tone or color of the object, in our case, it’s the subject.  A proper diffused value is one that reveal’s the actual color of the subject.  That is to say we have placed a proper diffused value if we view the subject as what it actually is in tone and color.

A standard light meter’s (an incident light meter, the one with a dome) job is simple.  It’s to read the light falling on the dome and tell you want settings to input in your camera.  This will render an image of your subject so we see the true tone or color of our subject, AKA set a proper diffused value.  Then and only then, can you build a system of exact control, using the diffused value as a reference to measure from.  Example, we measure a subject with a meter, and whatever the F stop reading the meter gives (the diffused value), we use that reading to compare a background reading and we can take steps to render a background black or white with zero guesswork.

In the video below, I want to make it very clear what is the diffused value and where it comes from.  Also, I cover what a white balance target is, what an 18% grey card and how the heck does it all work.  Also I explain the “diffused value” and try to shed light on what the proper exposure is?

Thanks for taking time to visit my blog today.  If you have any questions, please feel free to ask them below. I hope you all have a wonderful day.  Thomas Shue