There are 3 lighting tones that typically show form in a photograph – the diffused highlight, specular highlight and shadow. There are 2 edges where these tones blend into each other, typically referred to as the specular edge and the shadow edge. This tutorial looks specifically at the specular edge, which is usually the best visual cue as to the surface quality of the subject you are shooting (smoothness, roughness and reflectivity). But it can also be manipulated in very effective ways through your lighting modifiers and also in post-production.
In Lighting Theory 2, 3 & 4 we looked at the 3 tones that are involved in lighting contrast (Diffused Highlight / Specular Highlight / Shadow). In this tutorial, along with the previous tutorial on shadow edges, we will look at how those tonal areas blend into each other. Tone edges are typically where the diffused highlight meets either the shadow or the specular highlight and what the primary consideration in both cases is how abruptly those two tones gradate into each other. This tutorial focuses on specular edges, which can be manipulated in a number different ways: 1) by altering the surface quality of your subject; 2) by manipulating your modifier; and 3) using programs such as Photoshop to manipulate the edge in post-production.