Exposure is a crucial part of photography – it controls the amount of light that hits the image sensor and changes the “brightness” of the photo.It is the defining factor that differentiates a pitch-black rectangular piece of glossy paper that you get back from the printers, from a beautiful photo full of rich tones and nice color.
That’s why it is important to understand how to use the three parameters that control exposure: aperture, shutter speed, and ISO. Each one of them not only affects exposure, but also changes other important aspects of a photo.
What is a “stop” of light?
When learning about exposure, it is important to know what a “stop” of light is. If someone tells you, “increase your exposure by 1 stop”, they mean that you should double the amount of light that hits the sensor, making the image brighter. On the other hand, if they tell you to lower it by 1 stop, you should halve the amount of light that hits the sensor. If they say you need to lower your exposure by 2 stops, you make the like 1/4 of what it was originally and so on, you get the deal.
So… how much exactly is “1 stop” of light? It’s hard to put into words but here is a comparison diagram: (click to enlarge)
What is “proper exposure”? The answer is simple: whatever looks good to you. Sure you can get grey cards out and do proper metering, but in this age there is no need to do so when you can take a snap and check the photo quickly on the back of your camera.
Entering Manual Mode – Who needs auto, right?
For the following lessons, change your mode dial to the “M”, which stands for “manual”. The easiest way to learn exposure is to actually dial in all of the numbers in yourself and see what shows up on the back of your camera, so make sure to read the next 3 lessons about on shutter speed, aperture, and ISO, and then start playing! Don’t worry if you don’t get it right away – it takes some practice.
Next>> Photo 201 – Shutter Speed