Ok we are going to start with some basics in the art of photography. Because so many cameras are automatic most people are unaware of what a camera is doing to record the image so we are going to start with some basic optics first :
Aperture, Shutter Speed & ISO
I have found a really great basic introduction to these aspects of photography via
Aperture is like the pupil of your eye. When there’s little light, your pupil dilates to let in more light. When it’s bright, your pupil contracts to let in less light. This is what aperture does for your camera. Not only does aperture have the ability to let more or less light into your camera, it also controls the depth of field. This is the range of distance that appears in focus. We measure aperture in “f stops”. See the chart below to understand the correlation between aperture and the number associated with it.
When your aperture is wide open (f/ 1.2-1.8), you can focus on one thing and let everything else in the photo go out of focus. The out of focus part of the photo is also referred to as “bokeh” (pronounced “bo-kuh”). For example, the photo below has an aperture of f/ 1.6. Notice only the honey bottle is in focus. Everything else is out of focus.
The next photo has an aperture of f/ 3.2. This is still pretty wide open, but you can tell that the lemon juice bottle and the Mod Podge is starting to get a little more sharp.
With an aperture of f/ 6.3, we now have all three items in focus, and the background is starting to become more sharp as well.
Now the aperture is VERY small at f/ 18, and our depth of field is very deep. You can see everything in the photo clearly.
So, how can you use aperture? If you’re taking a photo of one person (your child, for example), you can open your aperture way up to f/ 1.8 for a nice dreamy photo. Just make sure you focus on their eyes! Conversely, if you are photographing a group of people, you’ll need to close your aperture to at least f/6 – f/10 to make sure that everyone is in focus.
Keep in mind that your camera may only have a maximum aperture of 3.5. That is typical for a point-and-shoot camera. If you have a DSLR camera that allows you to change lenses, different lenses will have maximum apertures. I have a prime lens with a maximum aperture of 1.4. Most zoom lenses will have a max aperture of 2.8 or higher, so the lens you have will determine how wide you can open your aperture.
2. SHUTTER SPEED
The shutter is the mechanism that opens and closes to let light into the camera. Think of the shutter like your eyelids. Shutter speed is how fast the shutter opens and closes. In a nutshell, the slower your shutter speed, the more blur you will see in your photos. The faster the shutter speed, the better you can stop motion. So, let’s say you’re outside photographing your son running around the yard. If you want to get a photo that crisp and clean with little to no blur, you need to have a really fast shutter speed. Shutter speed is measured with time. The photo below had a shutter speed of 1/50, or one 50th of a second. My niece is running around, and my shutter speed wasn’t fast enough to stop her motion in the camera. On the other hand, you can show motion in your photo with the use of a slow shutter speed if you want. It can be a cool look either way.
In the photo below, I was inside at a Central College basketball game. The lighting typically isn’t great in gyms, so I had to raise my ISO to 400 so that my camera would be more sensitive to the light, and so I could have a faster shutter speed to stop the motion of the players. For this photo my shutter speed was 1/160, or one 160th of a second. Pretty fast, but there is still motion in the photo, which lets the viewer know that this guy was running pretty fast! Yet, I still have his torso in focus and sharp. Makes for a cool look.
Now for this photo, I wanted to completely stop my cousin’s motion in the air. I was outside, so I had plenty of light to work with. I didn’t need a high ISO, and I was able to set my shutter to 1/1250. That’s one 1250th of a second. Pretty fast!
Taking a photo is all about managing light. Your camera has several tools to help you manage the light you’re working with. As you read in my last post, 3 of these tools are ISO, aperture, and shutter speed. In this post, we’ll focus on ISO. As I said in my last post, ISO controls your camera’s sensitivity to light. On many point and shoot cameras, you can change your ISO setting if you’re shooting in manual. On others, you don’t have to option to change ISO. Of course if you have a DSLR you can always change your ISO.
Here are several examples of different ISO settings and the effect it has on a photo. This photo is lit with natural light from a window. The room is fairly well lit, so I would normally choose an ISO of 100 because my camera doesn’t need to be as sensitive to pick up light since there is plenty of light in the room. If it were later in the evening, I would choose a higher ISO because I would have less light, therefore my camera would need to be more sensitive to the light. Also, notice that the higher ISO, the more noise we’ll have in our photo. Below is a photo of the same subject in the same lighting for each photo. I’ve included a close up for each setting as well, so you can see the noise better.
Can you see a difference between ISO 100 and ISO 1600?
So, what does this mean for you? Well, as I’ve said before, shooting in full manual mode gives you more control over the outcome of your photos. If you’re shooting in manual mode, you need to understand how ISO, aperture, and shutter speed work together to produce your photo. You always want to shoot with the lowest ISO number possible, to avoid unnecessary noise. If you’re outside on a bright day, use ISO 100. That is the lowest ISO available to you (depending on your camera, you may even have ISO 50). If you’re inside with very little available light, bump your ISO up until you get a bright enough photo: 400, 800, or 1600.
Got it? Okay now here’s the tricky part. Since I changed my ISO in each of the photos above, I ALSO had to change my shutter speed to keep the photo properly exposed. I kept bumping my ISO up which means my camera was perceiving more light. So I had to make my shutter speed FASTER so that the shutter was open for less time, allowing less light in. Here’s what would happen if I changed my ISO from 100 to 800 without changing my shutter speed:
Yikes! That’s way too bright. This is why I need to make my shutter speed FASTER to keep the photo from being too bright. That is how ISO and shutter speed work together. Don’t worry, my next post will be all about shutter speed, so I’ll talk you through this again if you’re super confused!
This week, if you have a camera that allows you to change your ISO, spend some time playing with it. Go into different light situations (outside in the morning, outside in the evening, inside, etc.) and change your ISO settings to see what happens.