Contrast is one of the most important things to understand when taking photographs but, as is usually the case, too few people take the time to consider what it means.  While there is a vast amount science and photo theory surrounding photography subjects like this, applying the basic concept of contrast doesn’t have to be hard.  It is a fairly logical idea and even the casual photographer will see improvements to their photos if they become aware of what contrast is.

Contrast applies to all kinds of photography but is best understood in terms of black and white.  The idea is that when things of different shades are placed within the same frame they contrast with each other.  If the subject of the photo happens to be pure white, to take an extreme example, and the photographer places it in front of a background that is pure black, then the result is what is known as high contrast.  The obvious result is that the eye will be drawn towards the contrasting white subject.

This is what makes silhouettes so effective in photography.  No matter where the silhouette lies in the frame it stands out quite easily. 

Because light and dark contrast so plainly, the lighting in a photograph is of utmost importance.  For most photographs the photographer would want the subject lit differently then the surrounding area to take advantage of contrast. 

Exposure plays a key role in this as well.  There is never just one level of contrast that will work for a photo so the photographer has to make a decision.  An underexposed photo will have lower contrast than a properly exposed one.  If low contrast is the desired effect then underexposing a shot is an easy way to achieve it.

For casual photographers who want to adjust contrast without fancy lighting or exposure controls there is an easy way out.  Almost any digital camera available will let you preset contrast levels to high, low and everything in between.  This is especially great for things like landscapes when you can make several attempts at getting the photo right. 

With color contrast there are a few differences.  The photographer isn’t necessarily looking at light and dark.   The entire photo can be equally lit and still have a lot of contrast because a lot of colors have distinct characteristics.  Blue and green share similar properties and so they don’t contrast very well, whereas red and green are considered opposites and really jump out against each other. 

Colors are also described in terms of cool colors and warm colors.  In almost all cases a cool color will contrast with a warm one.  To get a better idea of how this works in a photograph, picture a red brick wall.  Imagine that all the bricks are the same size and shape and there is nothing in the photograph other then the wall.  Nothing in that photo grabs your attention at all.  Now imagine one of the bricks is blue.  All of a sudden the blue brick is grabbing for the eyes attention.  Now imagine that every other brick is blue.  This causes a lot of contrast to exist in the picture and that in itself makes it pleasing to look at. 

If you train yourself to be aware contrast you’ll be able to improve the photos you already take as well as noticing all new things to photograph.