Aperture - - Photography Basics

The Art of Photography: Understanding Aperture

When it comes to photography, one of the most important aspects to consider is aperture, which is often referred to as f-stop. Aperture refers to the size of the opening in the lens that controls the amount of light that enters the camera. A wider aperture means a larger opening, allowing more light in, while a narrower aperture means a smaller opening, allowing less light in.

When looking at an image through a lens, you can see your vanishing points kind of merged somewhere over to the left and right in the middle. These two jars are where the focal point is, and so you can see that you have an edge of sharpness right here, indicating that this is where the lens was focused. This being a very wide aperture means you're going to have a very shallow depth of field, which is what it is - basically it's just about how narrow your depth of field is. You can even see this bottle right behind it or this jar here starts getting blurred out, obviously that's what you're dealing with with a very shallow depth of field.

For instance, in portrait photography, depth of field was used for specific reasons. This photo was shot on a 1.4 lens on a Canon, and you can see at 1.4 you have a shallow depth of field, really soft focus here. There's some lens effects here but anyway what you're seeing is the subject is in focus for the most part, while the background is allowed to blur out and creates contrast between your subject and your backgrounds, making the subject stand out a little better. It's just kind of a classic example of that.

However, if you stop down and to a smaller aperture, you have a greater depth of field. This photo shows the interior floor of the Tate Modern in London, and you can see here that this is a very wide depth of field. It's also a wide-angle lens but don't confuse that with your camera having a wider aperture - you can see everything is in focus here: these people walking in the foreground are certainly in focus, while all the way in the background, a couple hundred feet away, you see this back window and all the lights are in focus. In this case, you want to use a smaller aperture to get a greater depth of field.

Using a larger aperture can also be used intentionally for artistic purposes. For instance, this is kind of a medium depth of field shot, taken at a party in England. You can see that these two boys in the front right here are in focus, while that's obviously the focal point here and so you can see the background further back starts to blur out - these raindrops are still clear in the front, but nearly all of the stuff that's further back in the background is a little bit out of focus. This has a medium range of depth of field, which means it's not super tight but does start to taper off.

Aperture is also measured in stops. An exposure stop refers to a change in lighting, and there are these little notches here that measure light in terms of stops. Every time you move it one notch over, the overall lighting increases by one stop or decreases by one stop - this is referred to as the f-stop. The f-stop does have a mathematical formula, which involves dividing the focal length of the lens by the diameter of the working aperture.

In modern digital cameras, it's common for aperture to increase in increments of thirds of a stop rather than full stops. This can make it more difficult to understand aperture if you're learning this on a modern camera. The numbers of f-stop are arrived at through a mathematical formula, and they involve the focal length of the lens divided by the diameter of the working aperture.

The importance of understanding aperture cannot be overstated in photography. By controlling the amount of light that enters the camera, photographers can achieve a range of effects from shallow depth of field to deep, creamy bokeh. Whether you're shooting landscapes, portraits, or still-life compositions, knowing how to use aperture can help you create stunning images with depth and dimension.

"WEBVTTKind: captionsLanguage: enjoin us now on Flickr at flickr.com slash groups slash art of photography welcome to the art of photography my name is Ted Forbes and today we're going to talk about aperture now what is aperture aperture simply refers to and I have a lens that we use to show you here it's the size of the opening that the light is allowed to pass through in this lens it's obviously circular in diameter and as you can see I've got a lens here and as I open and close the aperture there's a series of blades in here and when I turn the aperture ring they open and close so if I come way down on this the the the hole that the light is allowed to pass through is very small and I can open it up and make it very large now the easiest way to think of this is think of it kind of like a faucet of water okay and let's say you have a bathtub to fill up and that bathtub being full is the proper exposure time that you need to get a good picture okay so if I'm going to fill up this bathtub I have two things working against me I have the the pipe here and if I close the hole the pipe less water is allowed to pass through if I open it up more water is allowed to pass through now if I have more water passing through I need less time to fill up that bathtub if I have less water passing through at a smaller opening it requires more time for that bathtub to fill up now if you think of the bathtub as being the exposure time needed to get your picture you can think of the the time that's needed to fill it up in relationship to this aperture being your shutter speed okay so the smaller the aperture the smaller this hole is the longer time you're going to need to expose light onto your either your sensor in a digital camera your film in a film camera the wider the aperture is the less time I need to fill up that bathtub or fill up my exposure okay so if it doesn't make any difference then why don't you leave it wide open all the time and just get everything quickly well there's a given of take with everything in photography it's kind of a trade-off what we're going to do is we're actually going to look at some images here I'm going to show you how aperture affects the image going to introduce the concept called depth the field here in depth of field simply is in the Fiat and the three-dimensional field of your image so if you're taking a picture of a landscape you might have things that are in the foreground there maybe five feet from the camera and then you have things that are way back in the distance maybe a mile away from the camera and how much is in focus well the wider the aperture the narrow your depth of field is going to be so I don't have as much depth of field so if I want all of that to be in focus what I need to do is stop down because the smaller that opening the more becomes in focus so let's look at some images and they'll probably help explain what I'm talking about here in terms of aperture okay so how does aperture have an effect on the image that you're photographing okay this image right here I think is a pretty extreme example of a shallow depth of field okay so what we have here is you can clearly see this is well maybe not clearly see because it's awfully blurry this was taken at a coffee shop counter and these are actually jars of coffee beans and shot diagonally here so you get a sense of depth you know obviously this is closer to use it's further away you can see your vanishing points kind of merged somewhere over to the left and right in the middle here these two jars are where the focal point is and so you can see that you have an edge of sharpness right here and so that that's where the lens was focused okay now this being a very wide aperture means you're going to have a very shallow depth of field so the area that's in focus is shallow basically is what it is that's your depth of field it's very very narrow okay so this is really no more than about maybe 2 or 3 inches may come out probably wider than that maybe about 4 inches you can even see this bottle right behind it or this jar here starts getting blurred so that obviously is what you're dealing with with a very shallow depth of field move on to another image here this is a portrait obviously and in this case depth of field was used for specific reason this was shot on a 1.4 lens on a Canon and you can see at 1.4 you have a shallow depth of field and it really is kind of soft focus here there's some some lens effects here but anyway what you're seeing is the subject is in focus for the most part in this background is allowed to blur out and what that does here is it separates there creates contrast between your subject and your backgrounds so it makes the subject stand out a little better so it's just kind of a classic example of that I don't know it's a great photo but anyway does do illustrate that for illustrative purposes now if I stop down and to a smaller aperture I have a greater depth of field in that case so in the next photo you can see this is the interior floor the ground floor the Tate Modern in London and you can see here that this is a very wide depth of field it's also a wide-angle lens but don't confuse that you can see that everything is in focus here these people walking in the foreground are certainly in focus and all the way in the background a couple hundred feet away you see this back window and all the lights are in focus so in this case you want to use a smaller aperture to get a greater depth of field okay so I don't want to single out things that blur out in the foreground or or vice versa to sharpen the foreground blur in the background because in this case it's the interiors the architectural rendering that's important so everything should technically be in focus on that and then finally this is kind of a medium depth of field shot this was another shot in England and you can see that these two boys in the front right here are in focus that's the obviously the focal point here and this was done at a party not necessarily wide open but a more medium aperture because you can see the background the further back it goes starts to blur these raindrops are still clear in the front these subjects are a little bit out of focus but now nearly is out of focus some of the stuff that's further back in the background so this has a medium range of you know from the depth of field here because it's not super tight but it does start to taper off and that is part of the shot that was done intentionally so okay now one other thing I want to mention about aperture here as aperture is measured in stops okay now an exposure episode we talked about light and what a stop of light is and it has these little notches here and every time I move it one notch over it increases the overall lighting by one stop or lowers it by one stop this is referred to often on cameras as the f-stop now the f-stop does have a mathematical formula what these numbers are how these numbers are arrived at and what it is is it's the focal length of the lens divided by the diameter of the working aperture here okay so that's how these numbers are arrived at so one stop of light for instance the widest this lens will open is an f-stop of 2.8 and the next stop down is going to be four and then I go to five six eight eleven sixteen so basically every two stops that number doubles and that's basically how aperture is is recorded or how its measured now one thing I will say is if you're shooting on more modern digital cameras just kind of the nature of the beast the perfection that's involved with these cameras and how specific you can get with your exposure you don't typically see your aperture go up in increments of one stop usually they're going up in third of a stop or sometimes the six of the stop depending on how how accurately tuned your camera is so sometimes for if you're trying to learn this on a more modern camera it's a little more difficult to to realize that you're actually incrementing in thirds of a stop instead of a full stop so anyway I hope that helps it's been the art of photography thanks for watchingjoin us now on Flickr at flickr.com slash groups slash art of photography welcome to the art of photography my name is Ted Forbes and today we're going to talk about aperture now what is aperture aperture simply refers to and I have a lens that we use to show you here it's the size of the opening that the light is allowed to pass through in this lens it's obviously circular in diameter and as you can see I've got a lens here and as I open and close the aperture there's a series of blades in here and when I turn the aperture ring they open and close so if I come way down on this the the the hole that the light is allowed to pass through is very small and I can open it up and make it very large now the easiest way to think of this is think of it kind of like a faucet of water okay and let's say you have a bathtub to fill up and that bathtub being full is the proper exposure time that you need to get a good picture okay so if I'm going to fill up this bathtub I have two things working against me I have the the pipe here and if I close the hole the pipe less water is allowed to pass through if I open it up more water is allowed to pass through now if I have more water passing through I need less time to fill up that bathtub if I have less water passing through at a smaller opening it requires more time for that bathtub to fill up now if you think of the bathtub as being the exposure time needed to get your picture you can think of the the time that's needed to fill it up in relationship to this aperture being your shutter speed okay so the smaller the aperture the smaller this hole is the longer time you're going to need to expose light onto your either your sensor in a digital camera your film in a film camera the wider the aperture is the less time I need to fill up that bathtub or fill up my exposure okay so if it doesn't make any difference then why don't you leave it wide open all the time and just get everything quickly well there's a given of take with everything in photography it's kind of a trade-off what we're going to do is we're actually going to look at some images here I'm going to show you how aperture affects the image going to introduce the concept called depth the field here in depth of field simply is in the Fiat and the three-dimensional field of your image so if you're taking a picture of a landscape you might have things that are in the foreground there maybe five feet from the camera and then you have things that are way back in the distance maybe a mile away from the camera and how much is in focus well the wider the aperture the narrow your depth of field is going to be so I don't have as much depth of field so if I want all of that to be in focus what I need to do is stop down because the smaller that opening the more becomes in focus so let's look at some images and they'll probably help explain what I'm talking about here in terms of aperture okay so how does aperture have an effect on the image that you're photographing okay this image right here I think is a pretty extreme example of a shallow depth of field okay so what we have here is you can clearly see this is well maybe not clearly see because it's awfully blurry this was taken at a coffee shop counter and these are actually jars of coffee beans and shot diagonally here so you get a sense of depth you know obviously this is closer to use it's further away you can see your vanishing points kind of merged somewhere over to the left and right in the middle here these two jars are where the focal point is and so you can see that you have an edge of sharpness right here and so that that's where the lens was focused okay now this being a very wide aperture means you're going to have a very shallow depth of field so the area that's in focus is shallow basically is what it is that's your depth of field it's very very narrow okay so this is really no more than about maybe 2 or 3 inches may come out probably wider than that maybe about 4 inches you can even see this bottle right behind it or this jar here starts getting blurred so that obviously is what you're dealing with with a very shallow depth of field move on to another image here this is a portrait obviously and in this case depth of field was used for specific reason this was shot on a 1.4 lens on a Canon and you can see at 1.4 you have a shallow depth of field and it really is kind of soft focus here there's some some lens effects here but anyway what you're seeing is the subject is in focus for the most part in this background is allowed to blur out and what that does here is it separates there creates contrast between your subject and your backgrounds so it makes the subject stand out a little better so it's just kind of a classic example of that I don't know it's a great photo but anyway does do illustrate that for illustrative purposes now if I stop down and to a smaller aperture I have a greater depth of field in that case so in the next photo you can see this is the interior floor the ground floor the Tate Modern in London and you can see here that this is a very wide depth of field it's also a wide-angle lens but don't confuse that you can see that everything is in focus here these people walking in the foreground are certainly in focus and all the way in the background a couple hundred feet away you see this back window and all the lights are in focus so in this case you want to use a smaller aperture to get a greater depth of field okay so I don't want to single out things that blur out in the foreground or or vice versa to sharpen the foreground blur in the background because in this case it's the interiors the architectural rendering that's important so everything should technically be in focus on that and then finally this is kind of a medium depth of field shot this was another shot in England and you can see that these two boys in the front right here are in focus that's the obviously the focal point here and this was done at a party not necessarily wide open but a more medium aperture because you can see the background the further back it goes starts to blur these raindrops are still clear in the front these subjects are a little bit out of focus but now nearly is out of focus some of the stuff that's further back in the background so this has a medium range of you know from the depth of field here because it's not super tight but it does start to taper off and that is part of the shot that was done intentionally so okay now one other thing I want to mention about aperture here as aperture is measured in stops okay now an exposure episode we talked about light and what a stop of light is and it has these little notches here and every time I move it one notch over it increases the overall lighting by one stop or lowers it by one stop this is referred to often on cameras as the f-stop now the f-stop does have a mathematical formula what these numbers are how these numbers are arrived at and what it is is it's the focal length of the lens divided by the diameter of the working aperture here okay so that's how these numbers are arrived at so one stop of light for instance the widest this lens will open is an f-stop of 2.8 and the next stop down is going to be four and then I go to five six eight eleven sixteen so basically every two stops that number doubles and that's basically how aperture is is recorded or how its measured now one thing I will say is if you're shooting on more modern digital cameras just kind of the nature of the beast the perfection that's involved with these cameras and how specific you can get with your exposure you don't typically see your aperture go up in increments of one stop usually they're going up in third of a stop or sometimes the six of the stop depending on how how accurately tuned your camera is so sometimes for if you're trying to learn this on a more modern camera it's a little more difficult to to realize that you're actually incrementing in thirds of a stop instead of a full stop so anyway I hope that helps it's been the art of photography thanks for watching\n"