Lens Basics - Focal length
Let's talk about some photography basics. As I mentioned before, one of the most important things in choosing a lens, whether it's to purchase or to shoot with out of your bag, it's choosing the right focal length and this is going to be listed prominently on any lens and there's a lot of lenses, that are known as fixed or prime lenses. These have a single focal length. They have one angle of view and they're kind of good at one particular type of thing and then we have our zoom lenses, which is going to have a variance from wide-angle to telephoto, perhaps like this 12 to 40 millimeter zoom lens. The second factor that you want to be looking at is the aperture and this is what lets light in, lets you determine how much light is coming in to the camera. Now, the maximum aperture is going to be listed on the camera cause that's a really important number to know. This particular lens has a maximum aperture of 2.8. We can kind of forget about the one colon, we'll talk about that later. So...
it's a fixed maximum aperture of 2.8. The zoom lenses, many of them, will have a variable maximum aperture, which means the maximum aperture will vary depending on where you are setting the zoom lens at that current moment and so, it could be four, it could be 5.6 on this. It depends on if you are at 14 or 150 on your zoom setting. So these two different categories of zooms versus primes, there has been a debate for a long time with photographers as to, what's the better choice? Do I get a zoom lens that's versatile or do I get a prime lens that might be better at a particular task? And it really depends on you and the type of photography that you do. I think for most people getting into photography, it's just a lot more practical to start off with a couple of zoom lenses that cover a good range to help, kind of figure out what you are most interested in and so, it's a good place to start, there's less lens changing, it makes things a little bit more easy. It's smaller than a whole collection of prime lenses. But when you find something that you're really particularly interested in, that's the time to start looking at prime lenses. They do let in more light, which allows you to use faster shutter speeds and there's a number of other benefits as well and they can be very small in size as well, which is really nice and if you want to get to the really nitpicky, they are a little bit sharper because they're a little bit simpler in their designs. So Olympus has a lot of lenses. They have a lot of zoom lenses, they have a lot of prime lenses and then they have a number of lenses that fit into a category that we just call special because they're not like other lenses and we're going to talk about all of these lenses as we go through this class. Let's talk about the focal lengths themselves and so, when you look through a camera, you're going to see a certain range of view from side to side and this is your field of view. With a 25 millimeter lens, it's going to very much mimic the perspective that we see with our own eyes. It's really hard to compare what we see with our own eyes because we have two eyes and they're scanning around and refocusing on things and so, angle of view isn't quite easy to compare with the human eye, but as far as the perspective, the relationship of a subject and something behind it is very normal with a 25 millimeter lens. If you want to see more from side to side, you go into the world of wide angle and there's different levels of moderately wide, all the way down to ultra-wide lenses and we have a lot of different choices to look at with these lenses here. Having a narrower angle of view gets you into the world of telephoto and, like the wide angle, there are lots of choices in here depending on what angle of view you need for a particular subject. Now, before we get too far in angle of view, there is a number of ways of measuring angle of view and it depends on which manufacturer you're looking at. But here in my classes, I tend to like to talk about horizontal angle of view. So you're holding the camera in its normal format position, which is a little bit wider. What do you see from side to side? And so that's our horizontal angle of view. So I'll start off with a collection of images here and I have shot with all of the different lenses including the different teleconverters to show you an example from one point of view. The camera is on a tripod, it's not going to move and I'm just mounting different lenses onto the camera. The 25 millimeter lens is your normal perspective, that gives you a very very realistic view of what you're pointing at and I think it's great for people who are new to photography to really work with the 25 millimeter lens. It forces them to make that translation from what they see with their own eyes to what they can capture in the camera. Let's go into the world of wide angle. We're immediately starting to see a little bit more with this moderate wide. Let's get to, kind of what I consider a really good wide, a 12 millimeter lens and then, all the way down to an ultra-wide lens at seven millimeters and you're seeing a lot more from side to side. Now, this may not be the best example for showing you what a fisheye lens but a fisheye lens is an uncorrected wide-angle lens where you will see even more from side to side. So let's zoom back up through the series now, through ultra wide, standard wide, moderately wide back to our normal lens and work our way into telephoto. So 45 is a very popular focal length with Olympus lenses and so, you'll see this for a lot of different options. 100 is considered a pretty good telephoto and 300 is their largest telephoto currently available, but they do have teleconverters which can magnify that and make it even stronger by a factor of 1.4 and two times. Now, I was kind of curious cause I was pretty much filling this small yacht in this frame and I had to go back onto Google Maps to figure out how far away was I, and I was able to measure it on Google Maps from where my camera was with the tripod and we were just a shade over a mile away from this boat and so, that's a 300 with a two times converter for a 600 millimeter focal length. All right, so let's zoom back and go back to our normal perspective here at 25, where we can barely see that boat in the distance there and so, that's a quick example of what you are going to see what the different focal length lenses. Now the easiest way to think about this, especially if you remember film back in the old days or you're coming from a different system that used a different size sensor is, 25 is your normal lens. That's your home base and you're going to go spreading out from there. If you want to go wide angle, you're going to go to a smaller number. Like 17, 12, down to seven, into the world of ultra wide. If you want something more telephoto, you're going to be going up to 45, 100 and 300, but just remember, 25 is your new home base number for a standard lens. All right, the 50 millimeter lens. Let's talk about, well, the effective here is 25 millimeter lens with Olympus and so, this is your normal or standard lens and there's a lot of reasons to choose to use this normal or standard lens. I like it when you have really good subject matter and you don't want to play any sort of funny optical games with your subject and so, normal perspective for an object that you can approach a little bit more closely. So in this case, you can probably move a little bit closer, a little bit further away, works very good for that. It's good for general purpose or lifestyle photography. It's very good for generally showcasing people. for doing tight head shots, you might want something a little bit longer than that. It's good for nice, small scenes and vignettes that you capture and see with your own eyes. They can also be very handy on their own, letting in more light cause there's a lot of 20, there's a couple of 25 millimeter lenses that have very wide apertures that work very well under low light conditions and so, it's good for a wide variety of work and I encourage any new photographer to use a and really learn how to use it. As you grow into photography, it may or may not fit into what you use, but I know, when I want to get back to just, kind of pure photography, just getting a basic lens on the camera like a 25 on an Olympus, is a great way to explore the world. So some things to think about when using a normal lens like the is that, it's got a similar angle of view. It's not the same angle of view as our eyes, once again, because our eyes see differently than lenses, but it's going to give you a normal perspective and that's going to be very good if you want to really showcase the subject and be honest and faithful about the way it appears for somebody else to see it and it's going to really emphasize the subject and not the process and there are times where it's kind of fun to play games with photography, with the fun lenses and I do like to do that, but sometimes, when you have a subject that is just really great, a normal lens is all you really need for that and so, great choice for those types of subjects. Next up, we're going to get into the wide angle lenses and so, a slightly wide angle lens or a moderately wide angle lens with Olympus is going to be the 17 millimeter lens and this is a great lens for different types of work like street photography. It's great for travel work. It's really good, I consider it as, just, you know, the perfect photo journalism or documentary lens and so, often times, you are needing something a little bit wider to show a subject in their environment and so, anytime you really want to focus on a particular subject, but also show what's going on around that subject and you want to be faithful to that subject about the size and distance relationships, this slightly wide angle lens of is a perfect lens for that and so, the environmental portraits, it's the perfect documentary lens for that type of work and so, any photojournalist is going to have this in their bag and it's going to be useful in so many different environments. Now we all do end up having certain favorites that fit our style and one of my favorites is going to be the 12 millimeter and that's because I like to do a lot of travel, I do a lot of landscape work and the wide angle lens, it's, well, it's wider than most people have on their phones and their basic point and shoot style cameras and so, it definitely, just right out of the gate has a distinctive look to it, than your average standard photograph and so, this is going to be something that I use in landscape photography, a lot of times where I have some subjects in the foreground that I want to include with a larger background, works very well. Works excellent for travel photography, where you are trying to show the bigger scene of the location that you're at and so, for anybody who does a lot of travel work, you definitely want a lens that gets down to 12. It can be a 12 millimeter lens. It can be a lens that goes down to 12 like the 12 to 40 lens and that way, when you want to show foreground, background subjects, big environments, does a really good job. You can also get it in really tight with subjects to put people right in the action. All right, next up, we have the ultra-wide lens, in this case, all the way down to seven millimeters and so, this is where we're getting into a unusual place in photography because not everybody has, needs a seven or a nine millimeter type lens because it's going to allow you to see quite a bit from side to side. Now to be honest with you, I don't use this lens real real often, but I do love when I get to use it because what it means is that almost everything in front of me looks great or look interesting, something I want to document and so, these lenses tend to render and have a lot of perspective to them. They allow people to really see where you are and what's around it. Obviously, with a really wide lens, it's good for small and tight environments where you're trying to show as much of that area as possible. Thus, they become very popular for architecture work and so, if you are into architecture, you're going to take a three week trip to Europe and you're going to visit all these churches and moss and buildings, you'd want to have something like a seven or perhaps a nine millimeter lens so that you can capture all of that. Once again, showing you perspective and so, working out on a kayak like this, nice to have that kayak tip in the front of the photograph. It's part of it, showing foreground as well as the subject in the background and so, the wide lens is its own unique style and a lot of fun for a lot of different types of work. Now something that you'll see talked about with wide lenses that you need to be aware of is distortion. Now, there are a couple of ways to talk about distortion. There's barrel distortion, where the horizon gets bent and that's something that's corrected for in all the lenses with the exception of the fisheye lens, which is a special category. We'll talk about it another time, but it does kind of distort the way the world is seen because there is a foreshortening effect. Objects that are closer to the camera will appear larger and it doesn't have to do so much with the lens as it does your positioning to the subject but the lens does end up capturing it and so, this Boardwalk here, the boards look much larger closer to the camera and this is something that is known as a tool that you can use to your benefit. When you are with a wide angle lens and you have subjects that are close to you like these penguins, they will be larger in the frame and more prominent in the story that you're trying to tell and so, if you do want to make a small object seem big and a bigger part of the scene, you take a wide angle lens and you get up nice and close to it. So anything in the foreground with wide angle lenses is going to appear more prominent, part of the story than things in the background, but it still allows the background to be a part of the story and this is a, I think this is a great example of that foreshortening effect, where this is a butterfly and I don't know how big this butterfly is, but it's probably not three or four feet across, it's probably inches across but if you can get up close enough, safely with a wide-angle lens, you can have it be a really big part of the frame and so, the wide angle lens is a great way to tell a different type of story. So some thoughts on using the wide angle lens. The obvious reason that you would want to use a wide-angle lens is when you can't move further back, you're limited by the space around you. It's going to show a subject within its environment. So when you want to show, you know, your neighbor who's got a tool shed, that's all, got neat tools all around the place but you want to show them in the tool shed, you have them a little bit closer to the camera, but you still are able to see the rest of the tool shed in the photograph and so, your foreground subjects are going to appear larger. Sometimes you do need to get fairly close. Sometimes a foot, two or three feet, depending on the size of the subject you're working with. Now these lenses also exhibit great depth of field, which means, it's pretty easy to have everything in focus by stopping the aperture down a little bit. So stopping the aperture down to 5.6, F eight, F 11 with a wide-angle lens, you'll have everything in focus from a few feet in front of the camera all the way into infinity and so, if you want to have sharp focus over everything, the wide angle lens is going to be the easiest way to get that done. You do need to be a little bit cautious when photographing people at 12 millimeters and below cause once you hit that 12 millimeter region, it starts distorting subjects that are way off to the edge and so, what you don't want to do, in my opinion, is to shoot a large group of people with a seven millimeter lens up really close. You're better off backing up a little bit and using a more modestly wide lens. That way, people on the edge are not distorted. This is a normal aspect of any sort of wide angle lens and so, that's just a good way to shoot that type of subject. All right, the next type of lens we want to talk about is the telephoto lens and so, we're going to be shooting with a 45, which is what we call a short telephoto lens here and so, this is going to be used for a number of reasons. So this is going to give you a narrower angle to focus in on a particular subject. Maybe you want your story to be more about one particular subject than the environment that it's in. So in this case, we're focused in on the microbus and the environment is part of the story, but it's not a major part, it's a minor part of the story and so, now we can start narrowing our topic. Now, these short telephoto lenses are known for one thing more than anything else and they're known as portrait lenses and so, if you like photographing people, especially head shots, faces and things like that, this is going to be a great lens for that and it's great for a number of different reasons. Number one, it gives you a normal perspective of the face. The size of the nose, the shape of the head and all of that is going to look normal. Second thing is, is that it's going to give you a nice working distance between your subject. You're not so far away, you need to use walkie-talkies. You're not so close that it feels uncomfortable to be so close to the person. You're going to be standing maybe, eight feet, ten feet away, two or three meters away from somebody and so you can have a nice conversation and get a nice shot of them as well. A third reason why they're very popular is for subject isolation because a lot of these lenses will have shallower depth of field and as you shoot with longer telephoto lenses, they will exhibit narrower and narrower depth of field and so, you can see in this shot by Jay Dickman, his eyes are in focus, but the wall behind, even his shoulders are going out of focus and so, it really brings your attention to the area that the photographer wanted you to see most clearly, in this case, the eyes and maybe a little bit on those wispy hairs on his beard and so, the 45 millimeter lens is going to be great for anybody who wants to do a lot of people photography and they have a couple of different 45 millimeter lenses depending on how in depth you want to get into this world of portrait photography that we'll go into specifics in the second half of this class. Going up in telephoto, we get to the medium telephoto, which is going to be the 100 millimeter lens and this is another favorite lens of mine, in that, I don't like to leave the house without something equivalent to around 100 millimeters and that's because, as a photographer and if you're a photographer, you're probably like me in that, you start to notice more and more details, little things, little vignettes, like this person holding a bunch of cigars and yeah, there might be a great shot of the person's face and the place where they are and the environment that they're standing but it's kind of nice to tell clean small stories. This is probably one of the easiest ways to accomplish good photography, is finding small vignettes, which tell a clean simple story and so, when your subjects are a little bit smaller, when your subjects are a little bit further away, that's the time to reach for this medium telephoto lens. Now the slightly shorter version of this, the short telephoto was used for portraits, but you can use this for portraits just as easily. You are a little bit further away. So you're able to get a little bit tighter headshots or you're able to have a little bit more compression with your subject. So if a subject has something else in the background that you want them to appear closer to or closer in size to, compression will be an effect that we're going to talk more about as we get into these telephoto lenses. All right, let's get up to the big telephotos now. A 300 millimeter lens is going to give you a very narrow angle of view and this is going to be useful for a lot of different types of subjects. So let's start off with going to the air show. So airplanes are notoriously far away and difficult to photograph because they're very small for the eye to see. The 300 millimeter lens is a great lens cause it really gets out there with that long narrow angle of view. So if we're doing any type of motor sports, this is a very good lens for that. Also extremely popular for wildlife photography. Animals tend to know what lens you are using and they try to get a little bit beyond it, but with the 300, you can overcome that a little bit and get nice and close to your subjects. One of the most popular activities is birding and so, if you are a bird photographer, the Olympus system, Olympus cameras with a 300 millimeter lens is one of the lightest weight fastest focusing, fastest frame per seconds, easiest used systems out there. It's a way of really reaching out there without gear that you don't literally need a car to transport it to and from where you are shooting and so, for the birding photographer, the 300 millimeter lens and the one four converter and the two times converter are great ways of really getting close to even very small size birds and so, for any sort of wildlife, any time you don't want to get eaten by your subject, the telephoto lens is a great tool and it's easier on this system because of the smaller size sensor, we're able to reach a little bit further with our lenses and so, all of the big lenses are quite a bit smaller than competition out there and this is one of the real strengths of Olympus, is being able to have a portable highly telephoto system out there. So telephoto lenses exhibit something called compression and for those of you who want to get nitpicky, yeah, it's not the lens, it's where you're standing but it becomes clear to see when you use a telephoto lens, that you get that effect in a shot and so, this is where you have multiple subjects that are at different distances. They're going to appear closer in size and closer together and you can use this compression to tell different types of stories and so, in this example, I was shooting the airshow over Lake Washington here in Seattle. We've got the log boom. So you got boats out on the water. Then behind that, is the plane. Behind that, is this row of houses and trees and then behind that, you have the skyscrapers of the city behind and all of these are being compressed into the flat image of this capture here and so, you can have several different elements, although they are at vastly different distances. Those buildings are probably a good full mile from where the airplane is and the airplane is probably about a half to one mile from where I'm shooting this particular photograph and so, anytime you want to have a subject, kind of portrayed against, an unusual background or against a background that has been compressed in an unusual way, like the cyclist with the city behind it, it makes your subject look very different than it does with a wide angle lens. You can use this compression to create patterns, as in this shot of the birds. We have a lot of different birds. They're spread out over a fairly large area. But when using a telephoto lens, they're all in the frame together and they helped create a pattern, which is a great way of telling a particular story. So some things to think about when you use a telephoto lens. Yeah, the obvious reason that you're going to use it is your subject is further away. You're not allowed, you can't get closer. It's not safe to get closer. Bring out the telephoto lens and you can start filling the frame with your important subject. Telephoto lenses also render a shallow depth of field. If you remember, when we are talking about the portrait lenses, that's one of their main benefits is that you get to shoot with a shallower depth of field. You can also minimize the background area because you're further away and shooting with a narrower angle of lens, you can utilize a small portion of a wall that's kind of a nice clean wall for doing your portraits and so, it's a little bit easier to get clean shots with the telephoto lens and it's going to compress that foreground and background for unusual compositions when you're trying to tell a different type of story and it is going to flatten the scene. It tends to have less of a three dimensional look to it than it does with wide angle lenses, but that's just the nature of using these telephotos. So going back to our list of lenses, of what we have and what we can use, remember 25 is your normal lens and I think as you go more wide angle, what happens is it gets to be a little bit more difficult. It gets more costly in the lenses and they also tend to be more difficult to use and this is true both on the wide angle side and on the telephoto side and so, I think for somebody learning photography, you kind of start in the middle and you kind of move outwards as your skill level and understanding of level progresses. Now before this, I showed you a series of photos taken with all the different lenses to show you what it looks like standing in one point of view and changing lenses. Well I'm going to do it again, but in a different way, I'm going to be moving forwards and backwards with one particular subject to show the relationship with that subject versus the background. So let's take a look at one of Seattle's historical icons, J.P. Patches. Used to watch him as a kid on TV and he had tuned in and he could see the other way through TVs and he'd wish you "Happy Birthday" on your birthday and so, we got a statue here of him and this is shot with a normal lens and J.P. Patches here is going to stay the same size in the frame. But notice what happens to the background, when we go down to wide angle. You're able to see more of the street and the building and the bridge behind it. We'll go all the way down to a fish eye and you can see kind of the funky effect that you get with the fisheye lens. Let's come back to the normal lens. At 25 and now we're going to go into the world of telephoto and in order to get these shots, I'm going to have to move away from the statue and so, notice how we are having a smaller area in the background, and now we're shooting with the pretty strong telephoto of 100 and all the way out to 300. We've compressed the subject against its background. We've lessen the size of the background. We've simplified it. We've also gone to a narrower depth of field because of its, the factor that it's a longer lens. We'll go back to the normal lens and see what it again, looks like there and so, I encourage you, if you have different lenses, different zoom lenses, different prime lenses, use those different lenses to practice and see what you get and what type of stories they tell because when you walk into a new situation and you think ah, I need to take a photo of this, you want to know which lends to reach for and each lens has a little different story. Let's do this again, another place in Seattle. We're going to shoot with a wide-angle lens. Our foreground subject is really large. Our background subject is really small. As we move further away, but use a more powerful telephoto lens, the relationship between the foreground and background changes. I'm gonna back up through these again, just to get this example and so, I call this a Hitchcock Zoom because Alfred Hitchcock used this dolly zoom in a number of movies that they made and so, learn your lenses, practice with them and get to know them really well.