In my 3rd part of my learning series I will be talking about Aperture. Just like shutter speed, what is it, what is it used for, and when to use it. Aperture and shutter speed go hand in hand. What you do with one will affect the other. You will use this to manipulate the camera to obtain the photo you are going for.
The aperture (also known as F stop) is represented on your camera by a number such as 1.8, 8, 16, etc. How low the number will go will vary depending on the lens you are using. Depending on where you are viewing on the camera this number might have an F before it, on my Canon this number is to the left of my exposure meter in the view finder, it shows an F on my LCD screen on back.
The aperture acts like the pupil of your eye. The brighter it is outside the smaller your pupil is, allowing less light to enter. The darker outside it is your pupil becomes wider, allowing more light in. The same holds true for you camera. The aperture can range from 1.8-22 (again this will depend on your lens). The smaller the number the wider your aperture is open, the larger the number the smaller the opening.
So now we have a little understanding of apertures, what does this all mean and how do we use it. Just like your pupil if you are in a dark room (gym, restaurant, etc.) you need as much light as you can to enter the camera to expose the shot properly. There are 2 ways to do this a long shutter speed as we discussed last week or a wider aperture. When you have your camera on a tripod as long as the object is not moving you can get away with using slow shutters. But if you are shooting your kids basketball game, a birthday party, or holding your camera in your hand, you need to have a faster shutter speed set. So to offset the faster shutter you have to have your aperture open wider (smaller number). You can also use this when outside shooting wildlife, sporting events, etc. to get a faster shutter speed to freeze the action.
The opposite also holds true. Say you are out shooting in the mid day with bright sun light and you want to show motion in your picture. Such as a soft lines on waterfalls, a car passing by, etc. Well as we mentioned last week you need to have a slower shutter speed. If you are in a bright area and you use a smaller aperture (larger number), this will allow you to slow down your shutter speed.
Are we confused yet, I know I was, let’s get lost even more…One more thing that is affected is your Depth of Field. Depth of field is what is relatively in focus or sharp in the picture. Just like your pupil if it is open wide not much of what you look at is in focus, but as it adjusts and becomes smaller more things become focused. As you will see in the photos below as the F-stop increases, the opening of the aperture becomes smaller, resulting in more things in focus.
So why would your depth of field be important? Let’s say you are shooting a portrait but the background is filled with people, if you use a smaller F-stop it will blur that background more so your subject pops more out of the picture. However if you are shooting a landscape you want more of the scene in focus, so for that you will use a larger F-stop and more of the scene will be in focus. Also if you are shooting a person but want the background to be somewhat in focus you will use a larger F-stop as well.
Besides aperture on the camera, distance will also affect your depth of field, as well as the zoom on your lens. The distance from the camera to subject and subject to background. We will get into this later down the road.
As mentioned earlier in this post here is some photos showing examples of how the F-stop affects the photo. I did not change distance, focus point, or anything else. Each item is about 6 inches from each other and the apple is about 24 inches from the camera. Only thing that was changed was the aperture. (And shutter speed to correct the exposure)
In this first photo the aperture (f stop) is set to 1.8. As you can see just the apple is in focus, the rest is pretty much out of focus. This photo really highlights the apple alone, and removes some distracting features in the background. This is great for portraits, the subject is in focus and distracting background items are blurred not taking away.
In this next photo you can see that the orange comes into more focus. F-stop is f4. This and the next shot might be good if you are shooting a person and want some of the background in focus. It’s not over powering to take away from the person but its strong enough to be able to make out the background. (ie like in front of Eiffel tower, Disney Castle, etc.)
You can click on the photos for a larger view. There are many more f-stops that will fall in between each of these photos, with each one the change will be less dramatic.
This was a pretty long post, if you have stayed with it this far thank you. If you have any questions or would like to know more leave a comment or feel free to contact me.
Tommy Hurt Jr.
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