One of the questions often asked by beginner photographers is “what in the world is aperture?”, or “what are all the Av, Tv, P and M modes on my camera?” The latest cameras may have great Auto modes, but they are never 100% reliable. I’m sure you have encountered photos shot in Auto mode that are either too bright or too dark. Mastering exposure is the foundation to better photography. So first, allow me to briefly explain how a camera records an image.

How cameras record an image

In layman terms (I try as much as possible to use non-technical terms to explain stuffs on this blog), cameras take photos by capturing light onto their sensors. Normally, light don’t reach the sensor until you depress the shutter release. As you depress the shutter release, the “door”, that is the shutter, opens up. And there is light!

Simple? You bet. But what controls the amount of light reaching the sensor before the shutter closes again? They are none other than the big three, aperture, shutter speed, and ISO. Understanding how they control the amount of light is the key to mastering exposure.

Aperture is located in the camera lens and is simply an opening that determines how much light passes through the lens. Making it bigger naturally lets more light in, and smaller means less light. But the numbering system used can be confusing, the smaller the number, the bigger the opening.

Shutter speed is the amount of time the shutter opens up before closing again. In typical conditions, the speed is in fractions of a second. Hence, you usually see figures like 1/80 or 1/200 on your camera.

ISO is the sensitivity of your sensor. The higher you set it, the more sensitivity your sensor is to light, but at the expense of visible “noise” on your resulting image.

Taking a photo is very much like suntanning

You must be wondering why there’s a photo of this hot pair of legs up there. I’m going to use my favorite analogy to explain aperture, shutter speed, and ISO. Suntanning.

Suntanning is really very much like taking a photo. You don’t want to get sunburnt, and neither do you want to waste your time not getting any tan. It has to be just nice. Like a photo, more often than not, you want the exposure to be just nice. Now, imagine ISO as the sensitivity of your body to tanning. That is, if you are someone who doesn’t tan easily, you have low ISO. And imagine aperture as the SPF of your favorite sunscreen lotion (my favorite is Banana Boat). The lower the SPF, the faster you will risk getting sunburn. Lastly, imagine shutter speed as simply the amount of time you spend basking under the sun.

So, to get perfect exposure is simply a matter of adjusting your ISO (skin’s sensitivity, which is unfortunately not adjustable) to an appropriate setting, choosing a reasonable aperture (lotion’s SPF), and picking the correct shutter speed (amount of time in the sun).

There are various other ways to explain, but I find suntanning the most helpful. Many people gets confused by the aperture numbering system, so with the suntan analogy, just remember that the number can be liken to the sunscreen’s SPF. That is, the higher the number, the less light will reach your camera’s sensor.

Go ahead, experiment!

Other than just exposure, each of the three settings have its own unique impact to other aspects of the resulting picture. They can open up various creative opportunities and we will discuss about them in another post very soon. But right now, go out and shoot! With digital technology, there’s really no harm in experimenting. Armed with your new knowledge, go out and snap away.

For those of you who are already masters of exposure, do share with us your tips and tricks to exposure in the comment box below.