Objective and Subjective Lighting
Previously I have mentioned how we all make a conscious decision on how we want our finished image to look like before we release the shutter. No matter how vague that initial idea, there will still be a deliberate choice to allow light to be exposed to the frame therefore representing our subject in a chosen way. In its most basic form this idea will be that there is enough light hitting (reflecting off) the object to make it visible in the image all the way up to deciding if and how we want to modify the size, angle, intensity and shape of our light source to intentionally capitalise on the semiotic relationship the viewer has with the subject. Included here are two images of the same subject but lit in two very different ways to evoke varying responses. The image on the left is shot with a directional soft light that envelops the skin and emulates the light from a window. The image on the right however is shot using a very hard-light from a ring flash that accentuates any tone with a sharp drop-off in light to dark and is used to give a more fashion feel to the shot. I have not even mentioned the choice of pose, styling, colours or post production options, all of which should be decided upon consciously or otherwise, to achieve a shot. In short, apart from actually lighting a subject accurately to portray its shape and features, and by accurately I mean correctly exposed, the rest is down to personal style. To photograph a fresh green apple correctly it would be lit to portray it as green, this is objective, portraying it as anything else is seen as the image looking wrong. You choosing to hard-light the apple to accentuate its shine with spectrals or deciding to add more light to fill in the shadows and minimise shine by using a softer light to portray it as a more natural and organic apple is subjective, this is up to you.
Areas of Illumination
If you were to point a single light source at an object that is of one tone you would see at least three different densities occur. The areas of light on a subject can be classified as shadow, diffused and specular. You would also witness the areas of change between these regions, they are known as edge transfers.
This is the correctly exposed area, representing the true tonality of the subject, or the natural brightness of the subject. This is objective, to truly represent the subject in question we have to document it accurately. A purple ball photographed in any other way than to depict it as purple would be classed as the image looking wrong.
This is under exposed in relation to the correctly exposed diffuse area. This is subjective, there can be no light or it can have a fill light to lessen the shadow. You can’t say this shadow is wrong, you can only say I like it or don’t like it. Altering the shadow edge transfer and the rate of transfer from the shadow tone into the diffused value tone can control how much shadow there is.
This is over exposed in relation to the correctly exposed diffuse area. Traditionally called, shine, hot-spot or sheen. It is the mirror image of the light source seen on the surface of the subject, most commonly seen as catch-lights in people’s eyes. Speculars as well as shadows, have edge transfers, only these govern how shiny a surface appears. Speculars are subjective and the size of them can be adjusted to personal preference, not rightly or wrongly.