Photographic Exposure: Learn the Fundamentals, part IiSierra May 31, 2019 1 COMMENT
The easier way to make photography is to set the DSRL in AUTO and let the camera do the work. However, once this is done then some other questions will arise: what are all those numbers showing in the LCD panel anyway? And how to control the camera to get away of the average f2 -1/30 -ISO100 the AUTO mode offers? And how to change settings at our convenience?
For this reason, let’s put in plain words the notion of exposure, which is easier said than done. Ergo, I will guide you right from the beginning in a simple 1-2-3 way, by using the smallest amount of indispensable information without any obscure jargon. Consequently, at the end of this series of posts: you will feel sure with your choices while mastering the triangle of exposure.
What is the Triangle of Exposure?
First and foremost, Aperture, Shutter Speed, and ISO are the three main elements of exposure. Hence, you may want to consider the correct exposure as a perfect equilateral triangle, meaning all the angles and sides are of the same importance. It cannot be stretch. You change just one part of the triangle, meaning the EXPOSURE, and it is no longer flawless. As a result, you will need to modify another side of the triangle to bring it back to perfection. The opposite edge or edges have to adjust to make the exposure exact again.
Let’s start with Aperture
Aperture is fixed with a circular iris inside our lens that works the same as the human eye. It contracts and relaxes to control the amount of light entering the camera. The bigger circle will help in low light situations. Images will be brighter. However, a small circle size is good for focusing.
TIP! The bigger the f/ number, the smallest hole and the opposite. We will go over the aperture in detail in a future post.
Understand your camera Shutter Speed
The camera shutter is a curtain in front of the camera sensor. The curtain stays closed awaiting the camera to shoot. When you fire the camera, the shutter opens and exposes the sensor behind to the light. Shutter speed controls the amount of light that has passed through your lens attending the sensor. The longer the time, the more light will enter, expressed in
Be familiar with the ISO concept.
ISO stands for International Standards Organization, which regulates the sensitivity to light reaching the sensor. Before the Digital Cameras, ISO did the same for film, being 100-160-400-1600 were the most used ISO marked in the film box and cartridges. ISO compensate the other two sides of the exposure, Aperture and Shutter Speed, in order to keep the triangle stretch. Elevate sensitivity facilitate less time (shutter speed) or the less amount of light (aperture) required for the correct exposure. ISO average is 200 -1600 in more digitals, but more expensive cameras achieve 3200, and even 6400 ISO in these days and the counting is only going up. Sadly, a higher ISO increases the noise or grain in our photographs, making them look very bad.
TIP! If you want to print big size don’t push much on the ISO.
Notice something? For every action we take in one side of the triangle, aperture stops for example, we need to make an equal but opposite adjustment on another part of the exposure triangle, meaning speed or ISO. If we are on location and need more speed, we have open the lens or increase sensitivity. If we change stops we need to make an equal correction in speed and/or ISO. I insist, always compensate.
Aperture, Shutter Speed and ISO can be complicated but it doesn’t have to be a science experiment. Guess what? Digital Cameras can be fine-tune manually in a stetting of our own creation, we will be taking about in the future.
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