We take it you’ve gathered that when it comes to photography, light is crucial. As a photographer, your job is to figure out how to manipulate light to create the best and most accurate shots possible. There are three ways to adjust how your camera takes in light on a DSLR: aperture, shutter speed, and ISO. In the interest of brevity, we’ll save shutter speed for another time. But for now, let’s talk aperture and ISO.
Have you ever looked into a camera lens when someone took a picture of you and seen a small circle inside of it? That circle expands and contracts to let in more or less light, depending on what you set it to do. It’s what photographer folks describe as “aperture.” The bigger the circle, the more light on the sensor, and the brighter the image. The smaller the circle, the less light on the sensor, the darker the image.
Aperture is measured on a scale of f-stops. Wider apertures have a smaller number, and more narrow apertures have a larger number. There are mathematical explanations about why these numbers seem contradictory (each f-stop below the widest lets in 50% less light than the one before it), but they aren’t essential to your understanding of photography as a beginner, so we’ll leave further research up to you if you choose, and keep on yammering.
The widest aperture on your lens varies largely by the type of lens in question, but is probably somewhere between f/1.2 and 2. The largest number, conversely (probably f/11 or something of the sort) is the most narrow aperture.
There’s one more essential thing you ought to know about aperture: it controls depth of field. Depth of field is what you manipulate to create a blurry, soft background vs. a crisp image through and through. Wider apertures create a more shallow depth of field–soft, blurry backgrounds. More narrow apertures create a deep depth of field–sharp, crisp (or at least, less blurry) backgrounds. Both are advantageous, but a working knowledge of how to capture images with a deep depth of field is particularly handy when it comes to real estate photography.
Using a smaller aperture to create a deep depth of field when photographing a house can be a real pain in the neck when you’re in an area that isn’t well-lit. Luckily, DSLRs come with another feature to compensate for the loss of light via aperture: ISO.
When you need to photograph with a deep depth of field and haven’t got a lot of natural (or even artificial) light, crank up your ISO! ISO, at its most basic explanation, controls the camera’s light sensitivity. Levels on modern-day cameras range from 100 all the way up to crazy numbers like 200,000, where 100 is less sensitive and 200,000 is more sensitive. You probably won’t ever use an ISO of 200,000, unless you like night sky photography, but the lower levels below 1,000 will become your ally.
Each level up in ISO allows you to capture half of the light via aperture/shutter speed than the level before it. So, when you turn your ISO up, you can ease your aperture back down.
Though ISO is frequently a lifesaver, particularly at levels 800 and below, it comes with a price. The higher the ISO, the more grain and noise your image will contain. So, toggle wisely!
If you’re serious about your pursuit of real estate photography, your best bet is to invest in a solid full-frame DSLR that can shoot at high ISO levels with minimal grain.