How Does it All Work Together?
Aperture f/5.3, 1/30 of a second on a tripod.
You can find, at a minimum, hundreds (probably thousands) of articles online, in books, and on video on this subject. Alternatively, you can attend a multitude of classes to learn about this subject, both private and in public institutions. But, even after studying through all of these channels, the only way you'll ever really get the concept of the triangle of these three elements is to use them. So, after getting the basic concepts, taking as many photographs as you can is ultimately the best way to cement the relationship in your brain. Even then, you'll find yourself in uncharted waters again and again, as each time you shoot the variables change. What you do need to learn is that if you change one setting, the other settings change to accommodate it unless you are in the manual setting. I encourage you to review the many different fine learning sites that exist on line in print and video. Also, take as many classes as you can and attend as many workshops as you can find and afford. I highly recommend an e-book called "Enlightened Photography," by Gary Crabbe: it is very detailed and well written and a great guide for beginners.
If you do not learn the basic premise of these three elements and what they do together and separately you cannot progress in photography. I know many people who buy expensive DSLRs and still use the "P" or "Auto" mode to take photos. I am not saying there is never a time to use auto, because auto or "P" does come in handy at times. However, if you want to control your shot of a subject to get a certain effect, you will need to control the camera, not let it control you. In the photo above I wanted to focus on the bird in front, the white egret, versus the bird in back, the blue heron. If I had let the camera set the mode I could not have gotten this shot. The camera would have had trouble focusing since the two birds were placed at different spots, back and front, and the camera would have no way of knowing what I thought was important in the photo.
There are a multitude of settings that cameras use today, but you will want to become familiar with aperture priority and shutter priority to begin with as these are primary settings for use in all types of photo situations. Aperture priority lets you set the aperture number and the camera sets the shutter speed as needed for each photo. Shutter priority lets you set the shutter speed and the camera sets the aperture number for each photo. At some point, you will also want to experiment with the manual setting; it really is not too different from the two settings mentioned above so don't be scared by it. I cannot emphasis enough how important it is to read your camera manual. I have downloaded both manuals for the two cameras I own and they are easy to refer to on my computer screen, much easier than in the written manual that came with each camera. You can even download manuals to your smartphone to have on-site as needed.
Aperture controls how much light hits the camera's sensor and affects the sharpness or lack of sharpness of the background of the photograph (called the depth of field), shutter speed controls how long (the duration of the exposure) the light hits the sensor and affects motion (creating stopped motion or blurred motion), and ISO affects the sensor's overall ability to gather light and can affect the noise (creating grain) in your photograph and allows more or less light in to hit the sensor, depending on the ISO set. Together, these three elements affect your overall exposure setting for any given photograph and can change dramatically based on the variables you encounter. These three elements should also alert you to the fact that photography is all about light! No light, no photos. There are various types of light and this is something you will want to study as you begin to learn more. As photographers we are in the business of seeking out and balancing light to get the photograph we envision, it's not an easy task.
If you do not learn the basic premise of these three elements and what they do together and separately you cannot progress in photography. I know many people who buy expensive DSLRs and still use the "P" or "Auto" mode to take photos. I am not saying there is never a time to use auto, because auto or "P" does come in handy at times. However, if you want to control your shot of a subject to get a certain effect, you will need to control the camera, not let it control you. In the photo above I wanted to focus on the bird in front, the white egret, versus the bird in back, the blue heron. If I had let the camera set the mode I could not have gotten this shot. The camera would have had trouble focusing since the two birds were placed at different spots, back and front, and the camera would have no way of knowing what I thought was important in the photo.
There are a multitude of settings that cameras use today, but you will want to become familiar with aperture priority and shutter priority to begin with as these are primary settings for use in all types of photo situations. Aperture priority lets you set the aperture number and the camera sets the shutter speed as needed for each photo. Shutter priority lets you set the shutter speed and the camera sets the aperture number for each photo. At some point, you will also want to experiment with the manual setting; it really is not too different from the two settings mentioned above so don't be scared by it. I cannot emphasis enough how important it is to read your camera manual. I have downloaded both manuals for the two cameras I own and they are easy to refer to on my computer screen, much easier than in the written manual that came with each camera. You can even download manuals to your smartphone to have on-site as needed.
Aperture controls how much light hits the camera's sensor and affects the sharpness or lack of sharpness of the background of the photograph (called the depth of field), shutter speed controls how long (the duration of the exposure) the light hits the sensor and affects motion (creating stopped motion or blurred motion), and ISO affects the sensor's overall ability to gather light and can affect the noise (creating grain) in your photograph and allows more or less light in to hit the sensor, depending on the ISO set. Together, these three elements affect your overall exposure setting for any given photograph and can change dramatically based on the variables you encounter. These three elements should also alert you to the fact that photography is all about light! No light, no photos. There are various types of light and this is something you will want to study as you begin to learn more. As photographers we are in the business of seeking out and balancing light to get the photograph we envision, it's not an easy task.
In general, if you want to focus on one subject and somewhat blur out the rest of the photo, you will need to set your aperture to a smaller F/stop number (such as f/4) which, incidentally, means the aperture device in the camera is wide open, letting in a lot of light. You also need to consider, as you set the camera, how much of the background you want in focus, the distance from the camera to the subject, what type of lens you are using, and the distance, i.e., 150mm versus 50mm: all of this affects your end result. You will also need to set your main focus point on the one subject or part of the one subject that you want to emphasize, thus telling the camera what in the scene is important to you. Also in general, depending on the way the camera is set, your main focus point and your exposure point go hand-in-hand. You can set your camera so that you can use a focus point and an exposure point separately, but this will not be addressed here. In most cases, using them together will work out fine. Let's say that your photo is being taken in good sun and your ISO is set to 100 or 200, which in most cases is a good setting to avoid noise (a kind of grainy look). If you use aperture priority, the camera will set an appropriate shutter speed. If the subject, such as the bird above, is not moving this works out fine. However, if the subject is moving, you may need to use shutter priority, which means that movement and controlling it is a key element in your photograph. Shooting a fast moving subject can be difficult at first and may take many tries to learn. Shutter speed for fast moving objects varies based on the speed of the subject and the lighting conditions, which can be best learned by experimentation. A bird in flight and a race car are two very different subjects. (Roll your cursor over the photos above to see the aperture and shutter settings.)
Taken at f/22 and 1/8 of a second on a tripod.
If you are taking a landscape scene and want the entire scene to be sharp, from front to back, then you would use a larger f/stop number, such as f/8 or f/11 or f/16, which would, incidentally, let in less light as the aperture device in the camera is not open very wide (imagine a donut with different size center openings: leaving smaller and larger donut holes!). The aperture device in the camera is very much like our eyes and works in a similar manner, depending on how we set it, letting in more or less light. So, now you've set your aperture to f/11 and taken that shot and when you look at it carefully in the back camera viewer (by enlarging the photo until you can see detail) you find that it's blurred, how did that happen? It could happen for many reasons, you moved the camera, the wind moved the camera, the setting did not work well with the speed of the subject, or you set the wrong focus point.
Overall sharpness in a photo is about more than just a correct aperture setting. I recently took photos of fall color, lots of aspen trees off Hwy. 395 (California) which is harder than it sounds as there is wind and the varying distances of trees and leaves to consider. Think of a tree and how it is shaped, lots of leaves and branches all over the place, not neat and tidy at all. The camera starts searching for focus and has trouble figuring out where to start for sharpness. You've set a focus point but everything after that is guesswork since the tree is not cooperating at all. One of the ways around this is to set the focus at about 1/3 or so into the photo starting from the bottom of the photo. Also, search for an item in the scene you want to be sharp (normally in the front area of the photo) and set the focus point there. Experts always say that using f/8 or f/11 will get you the best overall focus, but I sometimes still like f/16 best for a larger landscape scene. As you close the opening of the lens to f/8 or f/11 or f/16 you may need to reset your ISO to a higher number, perhaps 400 ISO, in order to let in enough light to get the shot (there is a way to set most cameras to a setting for a variable ISO with a minimum and maximum setting as determined by you so you don't have to worry about this as the light changes). You will need to experiment to see what works best for you. It's all about practice!
Overall sharpness in a photo is about more than just a correct aperture setting. I recently took photos of fall color, lots of aspen trees off Hwy. 395 (California) which is harder than it sounds as there is wind and the varying distances of trees and leaves to consider. Think of a tree and how it is shaped, lots of leaves and branches all over the place, not neat and tidy at all. The camera starts searching for focus and has trouble figuring out where to start for sharpness. You've set a focus point but everything after that is guesswork since the tree is not cooperating at all. One of the ways around this is to set the focus at about 1/3 or so into the photo starting from the bottom of the photo. Also, search for an item in the scene you want to be sharp (normally in the front area of the photo) and set the focus point there. Experts always say that using f/8 or f/11 will get you the best overall focus, but I sometimes still like f/16 best for a larger landscape scene. As you close the opening of the lens to f/8 or f/11 or f/16 you may need to reset your ISO to a higher number, perhaps 400 ISO, in order to let in enough light to get the shot (there is a way to set most cameras to a setting for a variable ISO with a minimum and maximum setting as determined by you so you don't have to worry about this as the light changes). You will need to experiment to see what works best for you. It's all about practice!