Terms – Exposure

I have written several posts that mention photos should be properly “exposed”. What does it mean to properly expose a photo? Good question. That is exactly the issue I intend to demystify.

“Back in the day” when every photographer used film to capture a scene for posterity the process included light rays piercing the film and chemical coating. When I refer to exposure, it is based on this process and how long the film is “exposed” to the light. If the film was left available to light it will be unintelligibly “bleached”.

So what this means in our digital world is we look at our digital exposures for areas that does not accurately represent the colors of our scene.

Proper exposure is not dependent on your field of photography. For example, a photo-journalist does not use a different measure for proper exposure than a commercial portrait photographer would. Each vocation specialty may prefer different exposures for their purposes, but there is one common key; they all want their subject in this range of proper “exposure”. We will discuss this more in-depth in our next post “Terms – Exposure 2”.

Exposure is effected by length of shutter speed, amount of added light (flash, strobe or constant) and lens aperture. All of these we have covered in earlier posts. For now, what are the keys that will help us discern a proper exposure?

Detail – How much detail is visible in the photograph? Detail represents the photographic subject and the surrounding scene.

Depth of Shadow – How dark are the shadows in the photograph? This will cause detail to be obscured.

Bright areas without detail – What areas in the photograph are saturated with more light than necessary? This will cause detail to not be visible.

As you look through pictures take some time to look at shadows and bright areas. Look for detail and consider other places the photographer could have stood for more or less light to expose the shot.

Skin Tone

People can become upset when ethnicity is brought up, which is not my intention in this post. This post simply is to draw out the courtesy which photographers should extend to others whom may have preference to their appearance.

Skin tones vary from person to person and it is not so much the slight variations we will discuss here, but the contrasting tones.

Photography, as we have been discussing on recent posts, is in general terms the art of capturing the subject in the “perfect lighting”, or as I have put it “properly exposing” your focal point.

An interesting point of history quickly; the use of the word “expose” comes from the time when film was the standard medium product for transferring current events to two-dimensional record because of the chemical reaction begun as the film comes into contact with light and the heat created by it. Thus the film was “exposed” to light and heat.

Light sensors in our cameras can be tricky especially when in this case we want to be sure that we show-off the face of our subject. If that means taking a darker shot so that our subject is not “washed-out” or adding light so that our subject is not a silhouette, we know what should be added to make that great shot.

Family photos are always more appreciated too when mom can see the each face of her loved and ever irritating children. (Oops! Did I just type that?) It is important however to realize that art is not void of science and utilizing the foundation of science for artistic creativity in your family photos, is exactly the inspiration we desire for you. I may sound like an expert, but please remember an expert is only a drip, under pressure. So please, enjoy your leisure!

Light Has Color? Part 2 – White Balance

Have you noticed some shadows have a little bit of color to them? Clouds for instance; some clouds on mostly clear days have a sort of blue hue to them. I can not help but wonder in noticing this and with the understanding of the how and why rainbows are made we can understand the process of a camera’s White Balance.

Looking at pure light as a simple harmony of ROY G. BIV producing a brilliant “white”, we have laid the foundation to working with camera White Balance. Now camera are not charged only to filter natural sources of light but also other forms of light produced by man-made light sources. Since we have seen that light can be divided into 7 color forms, the basics of our study tell us that we will be dealing with more of 1 color than the other 6. It is possible that we would be dealing with a sever lack of 1 or more colors, but since our color pallette is only based with 7, our filters can be adequately limited.

White Balance is the effort of compensating for the lack of or overdose of a specific color through the use of filters. This is also the job of Image Specialists. One of their most common jobs is “color correction”. So software is outfitted with the ability to manipulate the colors which may lack or overwhelm the captured photo.

For interest sake I have made a list of ways that light is produced, natural and man-made.

Element (Metallic element made to conduct enough energy to glow without quickly exhausting the element’s lifespan.)
Vapor (Gases – Fluorescent, Mercury Vapor and Fire are uses of vapor in proper conditions to yield the production of light.)
Chemical (Liquid – Phosphorescence and Glow sticks)
Electronic (LED)

Take care and do not be afraid to ask questions. Learning is a wonderful opportunity!