Exposure in Photography Continued

Exposure was explained a bit in the previous article. For a basic understanding the article is a good and must read but do not take this that easy. Exposure is the crux of photography and creative usage of the same can actually create magic.

We understand from the previous article that there are certain ways in which we can control exposure. These are Shutter speed, Aperture and ISO. Always remember these are mere tools, creativity comes into effect when you actually use these for your requirements. we can easily control exposure using any of these tools or all combined. We'll covering the photographic effects of these soon. As we talked about the above three pillars, which are the basic fundamentals for exposure, there are still some concepts that are important to get your desired effects.

We all talked about proper exposure or perfect exposure. What exactly is a proper exposure? Not too much bright, neither dark. Is this what we mean by proper exposure? Or is exposure, just a sensory reaction to incident light? Lots of questions and heavily debatable topic. Since, the idea here is to be bit more simple and hence for our understanding I'll try to explain in much simpler terms.  

"In simple terms a properly or a perfectly exposed picture would mean capturing maximum possible details or information of the subject." 

Is that it. Is this all about exposure that we scream about. Yes, and trust me there are just three things that we have already discussed, that will effect the exposure. There are some important concepts that may not be effecting exposure (as one may debate), but these are worth a mention here. 

If we look at the picture we see that rocks under the water. When we clicked the image the idea was to catch the details under water. Since, the sky was bright and its reflection was making it impossible to catch the desired. Exposure could ensure the rocks came up. If we look at the rocks with our eyes then probably we would seen them correctly. But, the camera behaves differently. It does not have a very accurate recognition of the contrast range from black to white and hence, it involves a lot of electronic effort by the camera to get your subject correctly exposed.  This does not look very digestive at the moment but for now lets go with it.

Just to clear your confusion lets talk about this with a different picture.

The above picture was a bit difficult. Not getting too technical here, but even 
if you get the exposure correct still you may not get what you are looking for. If we want the sky exposed correctly, the bird would be completely black, silhouetted against the sky. If we expose the bird correctly here, the camera would do what it did to the sky here. 

Putting it simply, the camera has certain ways of ensuring that the subject that we are clicking is properly exposed. In some ways this adds to our advantage, but in certain ways it might work against what we desire. For example, clicking a scene in snow could be a challenge. The camera would want to lower the exposure as it is set against the snow. 
There are certain algorithms that the camera works upon to expose the pics you click. This is called metering. For your desired effect you would want to use correct metering that your camera has to offer. Metering modes are present in almost all cameras nowadays. We will detail out the metering modes later. For now, just understand that to correctly expose your pic (to your desire), a correct metering mode is important.

Another important concept is white balance. A very simple explanation would be that you may need to educate your camera about the light conditions around. You may need to tell the camera that you are clicking the shot in shade or in daylight or under clouds or in tungsten light or in incandescent light etc. Technically, by doing this, you are actually trying to ensure that whites in your scene are actually white.
A camera would read light that is reflected. Difference light conditions would give different results and hence this. Every camera comes with this setup. I am though not very sure for film cameras. 
But, white balance is something that can be changed even after you have clicked your image. So, trust me this may not be a part of exposure as some may say but relatively logical to mention here. 

Summarizing for exposure.
Shutter speed,  Aperture and ISO would control the incident light, its duration and its effect. While these three are the basic features that can control the darkness and brightness level, a camera has its own activities and hence alterations. These are metering and white balance. We will discuss these in detail later, but, the point worth mentioning here is that these are also playing their parts in exposing a subject. Hence, always keep in mind these 5 things whenever you click a snap.