I’ve always been a picture person. Ever since I took my first photography class my junior year of high school, I’ve been in love with manual photography. Manual photography is such a different world that gives you so much more control over the appearance of the final photo. Yet, so many people have DSLRs and don’t know where to start, resorting to using automatic mode and other tools that use sensors to monitor your surroundings in order to determine the settings. I’m starting my Photography 101 series to help aspiring photographers combat just this very phenomenon. Up first, I’ll tackle the exposure triangle, which is composed of aperture, shutter speed, and ISO.
What is Exposure?
First things first, it’s incredibly important to understand what exposure actually is! Essentially, exposure is the term photographers use to describe how much light you’re letting into the camera. If there’s too much light, the image will be overexposed; likewise, if there’s not enough light, the image will be underexposed. The goal is to create a final photo that is balanced: well exposed, not too light and not too dark.
You may be thinking now, “but how do I monitor my exposure?”. Well, you’re not alone in this task. Cameras come with a light meter that monitors incoming light for exposure. You’ll find it down at the bottom of your viewfinder. Typically there’s some kind of triangle in the middle that indicates a well exposed shot. Anything to the right is overexposed, while anything to the left is underexposed. The middle is represented by the number 0 and you’ll see +1,2,3 on the right and -1,2,3 on the left to indicate just how over or underexposed your current settings make the photo. 0 is the goal, but if you have to go one way or the other, it’s better to underexpose than overexpose–you can more easily correct underexposed images in the post-processing of the photo. You may even find that slightly underexposing it according to your camera actually produces better results, anyways. I find that with my camera the colors are actually replicated better. But this is all personal preference, too.
Now that you have an understanding of what exposure is, let’s jump into the exposure triangle. First up: aperture.
Aperture
Aperture refers to the size of the opening of the camera lens. The larger the aperture, the more light the camera takes in. Large apertures tend to produce shallower depth of field (see: those blurry backgrounds you often see in portraits and macro photography) while small apertures will typically produce greater depth of field where every aspect of the image is crisp and in focus. You’ll also hear aperture referred to in terms of f-stops. Note that these terms are inverse, however–a large aperture corresponds to a small f-stop, while a small aperture corresponds to a high f-stop.
Shutter Speed
Shutter speed is simply how long the lens stays open and receptive to light. It’s represented by fractions in the format of 1/___th of a second. Using the logic of fractions, a high number in the denominator means a smaller amount of time that the shutter remains open while a low number in the denominator indicates that the shutter is open for longer. If you’re not using a tripod, it’s wise to avoid shutter speeds under 1/60th of a second, or more leniently, 1/30th of a second. This is to avoid the effect of camera shake, resulting from your hand movement, appearing in the image. You may think that you can hold the camera still–you can’t. Trust me on this.
ISO
ISO refers to the sensitivity of the camera to light. It has its origins in film photography, but is now replicated digitally. The lower the ISO, the less sensitive to light the camera sensor is. Higher ISOs are more sensitive to light, but at the cost of grain. Grain is much more apparent at high ISOs, so while you can more easily shoot indoors and in different lighting conditions, it’s at the cost of image quality unless you have the means to edit it out.
Using the Exposure Triangle
Aperture, shutter speed, and ISO are the three components of the exposure triangle as explained above. These three settings can help you better expose your pictures. While monitoring the light meter, think about your settings. Play around with the aperture and shutter speed according to your desired output in order to move the tick mark on the meter closer to the center. Changing the ISO is your last resort. I typically don’t change the ISO during a photoshoot except for possibly at the beginning or if the constraints on the lens are too great for me to be able to adjust it with aperture and shutter speed alone.
Exposure is so crucial in photography! Using the triangle can immensely help you better expose your photographs. I hope this guide gave you a better glimpse into all that is exposure, aperture, shutter speed, and ISO. Feel free to ask me any questions in the comments or just chat about photography with me!
