Canon® Lens Basics
All right so let's get started now to begin this class out before we can get into the good stuff I just want to cover a few basics because I know a lot of you have a lot of experience but we got some new people in the audience and they kind of need to get up to speed so we're just gonna spend a few minutes going over some of the basics before we get into the really good stuff first off interchangeable lances you're the best thing in the world I do not own this is this's kind of little secret about myself but I do not own a camera that does not have interchangeable lenses there's some really nice cameras that have fixed lenses but I I just can't get into them I love having the options and having so many options just expands my opportunity and it will do the same for you and that's why I love this all right are we on the right key note here is it what's going on here why why are we looking at shoes all right I I wanted to pull these up because I wanted you to think about lenses in a diff...
erent way all right so if you were gonna go hiking which one of these would you want to use okay most of you are going to probably say number one but what if you were wearing number three could you go hiking in a pair of running shoes yeah you could make it work in fact, some people like to hike in running shoes because they're lighter weight and they can run a little bit faster and go through the hills a little bit easier that way what if what if you had to go hiking in number two okay well I really wouldn't want to go hiking in those shoes but I could now the reason I bring this up is because a lot of people I get a lot of questions about lenses and people are really trying to figure out what's the best lens for this so I can buy that lens because I can't do it with anything else lenses are simply tools and you don't always need tohave the perfect tool for doing it you could do it with a lot of different things and just because one person even me says this is a great tool for using this doesn't 00:01:58.311 --> 00:02:02. mean you have to choose that these lenses our multi 00:02:02.07 --> 00:02:04. purpose and you can use him in many different ways 00:02:04.23 --> 00:02:07. it's it's up to your creativity and so like your shoe 00:02:07.92 --> 00:02:10. collection because we all have a different collection 00:02:10.28 --> 00:02:12. of shoes we have our casual shoes and are nice shoes 00:02:12.7 --> 00:02:16. and our athletic shoes it's nice to have a few pairs 00:02:16.62 --> 00:02:20. of shoes that really fit our needs and so I can't 00:02:20.56 --> 00:02:23. tell you what lends to buy until you know what you 00:02:23.74 --> 00:02:26. want to do what's important to you and what you're 00:02:26.49 --> 00:02:28. trying to accomplish. And so these are questions that 00:02:28.67 --> 00:02:30. you want to be trying to answer as we go through this 00:02:30.86 --> 00:02:31. class. 00:02:38.92 --> 00:02:42. So the tools that we use his photographers really 00:02:42.09 --> 00:02:46. our lances the camera can it do you know what a camera 00:02:46.35 --> 00:02:46. is 00:02:48.02 --> 00:02:49. uh camera 00:02:50.92 --> 00:02:54. a device that used to take photos a camera to a lot 00:02:54.49 --> 00:02:57. of photographers is a hunk of electronics you mount 00:02:57.52 --> 00:03:01. onto the back of a beautiful lands right that's I 00:03:01.68 --> 00:03:04. mean I like cameras but they come and go especially 00:03:04.52 --> 00:03:07. in the age of digital it's lenses that really hold 00:03:07.35 --> 00:03:10. their value in fact I've owned dozens of lenses over 00:03:10.31 --> 00:03:12. the years and I can think of at least three specific 00:03:12.42 --> 00:03:16. instances that I have purchased lenses and sold them 00:03:16.13 --> 00:03:20. for more than I paid for them lenses are a very good 00:03:20.07 --> 00:03:21. investment I'm not going to say you're going to make 00:03:21.39 --> 00:03:24. money buying clinton's is don't get me wrong but it's 00:03:24.14 --> 00:03:26. an investment you could make it if I think about everything 00:03:26.43 --> 00:03:29. in my house the only thing that has held it's better 00:03:29.92 --> 00:03:33. more than my lenses that I have bought is the actual 00:03:33.09 --> 00:03:36. house that they are in everything else you buy from 00:03:36.22 --> 00:03:39. close to tv's electronics your computer can you imagine 00:03:39.95 --> 00:03:43. buying a computer using it every day for five years 00:03:43.74 --> 00:03:45. and turning around and selling it from more than you 00:03:45.72 --> 00:03:48. paid for it that could happen with lens if you buy 00:03:48.86 --> 00:03:51. the right lens and it happens to go up in value so 00:03:51.8 --> 00:03:54. these are tools that are very valuable now the reason 00:03:54.99 --> 00:03:57. that we choose a particular lands more than anything 00:03:57.73 --> 00:04:00. else has to do with its angle of view what we see 00:04:00.8 --> 00:04:02. through the view for funny because that's that's what 00:04:02.84 --> 00:04:06. they do have an angle of you the next thing is probably 00:04:06.15 --> 00:04:08. going to be the maximum aperture the lens that's going 00:04:08.51 --> 00:04:11. to determine how where we use lenses of what type 00:04:11.66 --> 00:04:14. effects we can get out of and that's going to also 00:04:14.32 --> 00:04:16. have implications on our depth of field both the angle 00:04:16.64 --> 00:04:19. of you in the maximum aperture now there's all sorts 00:04:19.32 --> 00:04:23. of image quality issues that were going to talk about 00:04:23.25 --> 00:04:25. do you know what coma is we're going to talk about 00:04:25.06 --> 00:04:27. coleman explain it in here there's all sorts these 00:04:27.26 --> 00:04:30. little problems and I love going on the internet going 00:04:30.18 --> 00:04:33. to different websites about comparing different lenses 00:04:33.04 --> 00:04:37. in this class is not about comparing the technical 00:04:37.61 --> 00:04:41. specifications of one lens versus another in its chromatic 00:04:41.41 --> 00:04:44. aberrations and there's plenty of places that do testing 00:04:44.32 --> 00:04:46. on that we're not testing lenses were not judging 00:04:46.8 --> 00:04:50. them on sharpness it's important but you'll be surprised 00:04:50.29 --> 00:04:54. when this image quality it's not that important it 00:04:54.37 --> 00:04:56. is what it is once you get a lens that does the right 00:04:56.92 --> 00:04:59. angle of you has the right maximum aperture and other 00:05:00.49 --> 00:05:04. good characteristics physical size weight affordability 00:05:04.18 --> 00:05:06. once it fits your needs and it's got a little bit 00:05:06.49 --> 00:05:08. of chromatic aberration has got a little bit of a 00:05:08.4 --> 00:05:11. yeti well that's just something you kind of have to 00:05:11.28 --> 00:05:13. live with I mean think about it if you commute to 00:05:13.95 --> 00:05:18. work and on your commute to work you pass by a really 00:05:18.78 --> 00:05:21. ugly car I mean this thing is just hideous looking 00:05:21.91 --> 00:05:24. all right and you don't like looking at this car what 00:05:24.33 --> 00:05:28. do you do quit your job move take the alternate route 00:05:28.82 --> 00:05:31. toe toe work which takes an extra half an hour or 00:05:31.45 --> 00:05:33. do you just deal with it do you just live with it? 00:05:34.19 --> 00:05:37. All of our lenses are in perfect and so if you are 00:05:37.05 --> 00:05:40. on a quest to have a perfect lens I don't care how 00:05:40.33 --> 00:05:42. much money you spend you're not going to get it but 00:05:42.72 --> 00:05:44. you should be aware of the problems that you have 00:05:44.9 --> 00:05:47. because there are simple solutions to fixing those 00:05:47.27 --> 00:05:50. problems and workarounds if you do have those problems 00:05:50.73 --> 00:05:52. soon so we're going to talk about that a lot in the 00:05:52.77 --> 00:05:54. features and the technology section 00:05:56.09 --> 00:06:00. so we get to talk about specific kanan lenses in this 00:06:00.15 --> 00:06:02. class I was going to make just a general lens class 00:06:02.31 --> 00:06:05. but we decided to make it specifically organic so let's talk about the camera canon camera bodies they make a large collection of bodies and they could be roughly split into two groups those with a full frame sensor and those with the cropped frame sensor. And this is gonna have a huge impact on the lenses that you choose for your camera and so you need to know what type of sensor is in your camera and so figure that out if you don't know it off the top of your head because that's going to have great implications when choosing the lens because I am basing pretty much everything in this class off of a full frame sensor it's the standard we've used in photography for sixty years and I'm not changing it for this class so full frame sensor measures the same size as thirty five millimeter film we call it full frame some people call it a thirty five millimetre because it's the same is that I like to call it a forty three millimeter sensor because that's the measurement from corner to corner a p s c is the smaller size it is sometimes referred to as a one point six crop factor will talk more about that but it's a twenty seven millimeter sensors so if you want to compare the size it's twenty seven to forty three in size and here is why you need to know what size sensor is in your camera if we take the lands and it doesn't really matter what lands just any lands on a full frame sensor light goes through that lads and it is focused and it's around lens so it puts a round image on top of our rectangular sensor and that's our image all right very nice now let's take that same lands and let's mount it on a camera with a smaller size one point six crop sensor what happens will the lens doesn't change light goes through the lens and it does exactly what it did in the first instance but in this case the area that we're recording is smaller in size and the image is similar but it is a different angle of view and so it's that angle of view that is difference difference between these two models it's a cropped version of what we get with the full frame and there are advantages and disadvantages to the system it generally costs less because of so smaller size sensors are easier to manufacture then the large ones and so in general the larger the censor the better image quality for reasons we're not gonna have time to go into right now but I think both of these are valuable I have a full frame camera I have a crop frame camera because they both have their own advantages so when we talk about focal length is not the same thing is angle of you remember this slide here we have the same focal length but we have different angles of you because the sensor size is different now with cannon crop frame cameras they do have a special set of lenses thie f s lenses that air designed that have an image circle just big enough for the small size sensor and these air known as e f s lenses so they're specially designed for the small frame sensor. Now you can actually work with him on a full frame camera. But if you could mount them on there. The problem is, is that they would not illuminate the corners of the frame within with any image area. So you get all this heavy vignette ing or darkening of the corners, and it wouldn't work out. You don't really have to worry about making this mistake, because this won't even mount on your camera. But you want to be sure if you have a full frame camera, you're not buying f s lenses because they don't work on them. Now, the lens that has traditionally been known as the standard or normal lands is thief. Fifty millimeter lands. And if you mount that on a full frame camera, you're going to get a forty degree angle of view from side to side. If we were to mount that lands on a crop frame camera, we're going to get a narrower angle of view for reasons that we just talked about about twenty seven degrees in there. So fifty millimeters is normal if you have a full frame sensor now this is the gold standard that photographers talk about and I'll tell you what's kind of unfair is that most of you probably own a crop frame camera because whenever I teach classes it's usually about eighty percent on a crop frame camera and maybe twenty percent on a full friend camera they're more expensive and just fewer people have but that is the standard we had here too because it's been the standard for the last sixty years and nobody wants to change it it's it's kind of what we built into the lexicon of the way we talk so if you wanted I want the same angle of you you're going to need a slightly different lens you would need approximately a thirty five millimeter lands and that's going to get you about a forty degree angle of you so you have two different cameras that have two different sensors and two different lenses but they see about the same thing and so this is what we call an equivalent lens and not everything is the same and we're gonna have a little section on equivalence later on in the class but this is what we talked about it's an equivalent angle of you were going to talking more about that as we go into this first section the lenses are gonna have their focal lengths listed right on the top. Here we have a thirty five millimeter lands. This is known as a fixed or a prime lens, which means it doesn't zoom, will have zoom lenses. Twenty four dash seventy indicates the range that they go from, and then the next most important number that you want to look at is the aperture there's going to be a one colon and it's the number after the colon that's. Really important? The four indicates it's, an f four lands and, in this case, it's, a fixed aperture, which means it's, just one number. Most lenses that are zooms have a variable aperture like this three point five to four point five, which means the maximum aperture changes a little bit as you zoom the lens back and forth, and so that's something that is less desirable. But they're often a little bit smaller, lighter weight in less money. We'll talk more about those when we get into the specific zoom lands section of this class. So focal length is defined as the distance from the nodal point to the image plane now the nodal point is out towards the front of the lands and the image plane is right where the sensor is and this is why a fifty millimeter lands is relatively small in size if you were to compare it to how large a four hundred millimeter land says and so this is where we get the names focal length and where we get these numbers in the design of the lenses as I mentioned just a couple of slides ago there are two primary categories of lenses we have prime lenses which are single focal length lenses fifty being the normal lens and then we have anything less than that is going to be a wide angle lens so thirty five is a wide when we hit down to twenty we start calling them ultra wide lenses as we go to larger numbers than fifty eighty five's a telephoto we hit four hundred it becomes super telephoto and we have basically the same collection involving zooms as well and so we'll be talking about both of these throughout this class there's values to both so let me just quickly give you an analysis between zooms and primes which one's better huh gotta gotta choose one here zooms or more versatile because you have several different focal links all built into one lens I think this is great for photographers who are starting now, or her shooting a wide variety of subjects that don't have time to change lenses because changing lenses can be a real hassle time so mean, you can bring dust into the camera. There's a lot of places where it's just not convenient to be changing lenses, but if there is something very specific that you are doing the prime lenses oh, they could be really nice. These are the sharpest lenses that you're going to be able to find their faster, which means they let in more light they'll be ableto work in low light situations and forgiven size, they can often be smaller. For instance, in this example, right here, this is a twenty four to seventy, and we have a fifty millimeter right next to it, and this fifty millimeter actually lets in way more light than this twenty four to seventy. And so if you have something very targeted you want to do, set a prime or a set of primes could be smaller than a zoom lens. And so size wise, you really have to look at exactly the package that you want to put together and so what's better. It depends on what you're doing. I do a lot of stuff, and so I have some primes, and I have some zooms depending on what I'm choosing to dio