Nikon D90

DSLR Camera


These are the three variables that affects the exposure of your photograph. Exposure is the amount of light allowed to penetrate in the photographic medium (film/image sensor) during the process of taking the photograph. And the change of any of these 3 variables alters the amount of light that can pass through your camera.

You can imagine the three angles of a triangle as the symbol for each of the above variables. If any of the angle (e.g. originally 60x60x60) is changed (e.g. from 60 to 90) then other angles need to be modified as well to maintain the preferred exposure (e.g. to 90x45x45). We can think of the triangle as the preferred exposure for that particular subject under the environment’s condition. Note that preferred exposure value always depends on the photographer’s approval, though in photography it is always worth to consider the appraisal of the common eyes rather that to depend on your own appreciation since photos are usually shared to be viewed by others rather that for one’s self alone.

What is apperture? Apperture defines the depth and detail of the photograph. Like the opening of one’s eye, more details can be seen on the subject if the eye is widely open compared to half/quarter-opened eye. Wider opening allows more light to enter through the lens, while half opening allows less light. It is usually the apperture that is to be adjusted if you want to have a blurring effect on your background while having a clear focus on your subject. Of course, this can be affected by the distance of your subject to its background as well as the distance of your lens to the subject.

Shutter on the other hand is the length of time (speed) on how long will the opening of the lens be kept open. The slower the shutter the longer the lens will be opened, hence more light will be allowed to penetrate. While of course the faster it opens and closes, the lesser light it allows to enter. Fast shutter is the common setting for sports event or activity that requires constant movement. This is because subjects are on the move, otherwise when taken at slow shutter it will create shadowing/blurring effect which usually results in a crappy photo.

For landscape night photography, slow shutter is the very much appropriate setting to allow commercial lights to be have its dramatic effect on the image while the dark environement/scenery neutralizes the brightness of the exposure making a pleasant feel of the night. However, tripod is greatly demanded during night photography as our hands tend to shake always even we believe that there is no shake at all. Try and you’ll know.

The ISO is the variable that is least to be used or changed. It is usally the last option to be touched if the other variables are in limited control and can’t be modified due to environment/subject constraints. Based on personal experience, you can think ISO as the brightness adjustment when you are editing your photo using your favorite image editing tool installed in your computer. It is applied to the entire image equally where the higher its value the more grayish white your photo will be. Moreover, one of the drawbacks of setting your camera to higher ISO is the noise visibility in the image taken. The noise is the grainy white effect that you can see in your photograph. Human night photgraphy is the usual scene where one may need to increase the ISO setting. Though as my personal advise, it is always advisable to use other sources of light such as street lights, light from the moon, light from buildings, or maybe from your flash to brighten up your subject rather than increasing the ISO.

Remember that these three variables are the very basic yet very important things to learn in photography. Once mastered, then one can start levelling up to learning the other factors that may improve the quality of your photo such as white balance and temperature, lens filters, speedlights, light meter, etc.