Aperture: Maximum Aperture
So I want to talk next about the maximum aperture it's kind of leading into this whole section so the maximum aperture is that critical factor that photographers know by heart about all their lenses one point for so there's one a colon and then a one point for its the one point for that we're concentrating on the one and the colon or just kind of setting us up for the right number and so that is what is known as a fixed aperture that's one single number and you're going to get this on prime lenses now a lot of your zoom lenses have a variable aperture so is you zoom the lens in this case from ten to twenty two it's gonna vary from three point five to four point five which can be a little confusing if you're setting your camera manually and you zoom and all of a sudden something changes and it changes the amount of light that you are leading in and so serious photographers tend to avoid these but having said that a lot of serious photographers own these lenses because well that's the on...
ly way those lenses are made this is a zoom lands with a fixed maximum aperture which means you can use this lens at f or at twenty four and at seventy and everywhere in between you can also close the lens down to five six and eight eleven support this is on ly referring to the maximum number. I know some people get confused, and they're like the range of the apertura is three point five to four point five. No, no, no, no, no, no, that is the maximum aperture that various back and forth. You'll be able to stop this lounge lens down. Eight eleven, sixteen, twenty two, maybe, even at thirty two, depends on the lens. That's. Just the maximum opening, but very important number to know on all of your lenses. So what is this fifty millimeter one colon one point for what does that really mean? Because this looks a little like math and math is confusing and nobody knows what math does well, at least I don't I never did well in math but I learned math because it's important and photography so the one means it's a fraction it's one over one point for and the one is whatever focal length this's put that number over the number on the other side of the colon and so this case it's a fifty millimeter lens what's the focal length of this lens fifty all right then let's put fifty over one point four and since we have a very small little area to write this we're trying to do it in one line which is why we use this slash or the colon it means to divide by so we're going to divide fifty by one point four and we get thirty five so what is thirty five millimeters about a fifty millimeter lens will in this case the opening of the lands if you were to measure across the opening through the middle of the land's not the outside end of the lens but how much light can get through that lands it's going to be thirty five millimeters across and so that's how they determined that this is a fifty millimeter lands as it has this size of opening it has this focal length that's what? The aperture is going to be so we can figure out the size of the opening of any lands by taking the focal length dividing it by the f stop on it so this fifty one point four has a thirty five millimeter opening so can and also makes a one point eight let's figure out and it is a twenty eight millimeter opening so it lets in less light it's a little bit smaller oven opening on it cannon makes a one point two lands all right fifty invited by one point two is forty two millimeters so the size of that opening is a little bit bigger and you khun hazard a pretty safe guess that that bigger the opening means the bigger the glass the bigger the lands the more money the lands all right what about a few other lenses? A twenty for one point for same aperture they let in the same amount of light but it doesn't need to have his big of opening because it's a shorter focal length lance let's go all the way up to a three hundred two point eight two point eight two stops less light here but it needs to have a massive opening because it is such a long three hundred millimeter lens here the math does not work in favor of telephoto lenses and so this is how we get the numbers and there is a logic and reasoning behind it and that's always for me. It's comforting to know that they actually mean something important you don't have to do this math on a daily basis when you're actually pictures thankfully now prime lenses lenses that have one focal length have a variety of maximum apertures that in the canon lineup will range from f one point to f five point six and this has a lot to do with what focal inc they're doing and how much you're going to spend on the particular lands zoom lenses will also have a variety of maximum apertures there's a whole group of them that have a maximum aperture of f two point eight the largest collection have this variable maximum aperture that ranges anywhere between three point five and five point six and there is another nice little collection of lenses that I think are really quite nice good kind of middle ground between these two with a fixed maximum aperture of f four so let's talk a little bit about these different groups of lenses and why you would choose them and first off we want to talk about what what is fast your heel taught photographers talk about do you have a fast lens because I need a fast lens to shoot this could I borrow your fast lands? What do you mean by a fast lands? Does it run really fast? You know it means that it lets in a lot of light and allows you to shoot with the very fast shutter speed so kind of a general definition is everything above this line is kind of fast and everything kind of below it is kind of slow now it's kind of interesting is is f to a fast lance what focal length is it because if it's a fifty millimeter 00:05:58.253 --> 00:06:02. lands f two is not fast that's very normal but if 00:06:02.44 --> 00:06:04. it's a four hundred or two hundred millimeter lands 00:06:05.04 --> 00:06:08. that's a really fast lands so it depends a lot on 00:06:08.24 --> 00:06:12. what focal length it isthe your basic run of the mill 00:06:12.12 --> 00:06:16. zooms remember those two terrible aftermarket lenses 00:06:16.03 --> 00:06:18. that I started with this is where they were these 00:06:18.64 --> 00:06:21. air very slow lenses lenses that have apertures that 00:06:21.58 --> 00:06:23. air in the four to five six rage 00:06:24.83 --> 00:06:27. the fastest zooms if you want to zoom lens and you 00:06:27.15 --> 00:06:29. wanted to let inasmuch light it's possible you're 00:06:29.92 --> 00:06:32. looking at zoom's generally in the two eight region 00:06:33.46 --> 00:06:35. if you're willing to go with a prime lands you're 00:06:35.84 --> 00:06:38. able tto have lenses that are much, much faster and 00:06:38.65 --> 00:06:40. these are just the basic crimes you could get into 00:06:40.62 --> 00:06:43. these for less than a thousand dollars but if you're 00:06:43.91 --> 00:06:46. really willing to spend a lot of money on the top 00:06:46.59 --> 00:06:49. of the line primes you're going to get lenses that 00:06:49.03 --> 00:06:52. are very fast from white angle out to telephoto 00:06:54.06 --> 00:06:56. and so one of the things that I'm trying to show here 00:06:56.61 --> 00:06:59. is that if you need to let in more light what you 00:06:59.3 --> 00:07:02. want to get it you want to get a prime lands lens 00:07:02.24 --> 00:07:06. that does not zoom. Zoom complicates the lens manufacturing 00:07:06.08 --> 00:07:09. process, and it makes the lens much slower, which 00:07:09.35 --> 00:07:11. means not letting in its much light. So if you work 00:07:11.92 --> 00:07:14. in dark situations or situations, we issued a lot 00:07:14.88 --> 00:07:17. of people and action movement, and you need faster 00:07:17.72 --> 00:07:20. shutter speeds. The prime lens is probably going to 00:07:20.75 --> 00:07:22. be the best way to solve that problem. 00:07:27.22 --> 00:07:31. So fast, lenses what's the big deal. Who cares about 00:07:31.39 --> 00:07:33. fast lenses? Well, there's, a number of things going 00:07:33.58 --> 00:07:36. on. When you have a fast lands, you're going to be 00:07:36.42 --> 00:07:38. able to set faster shutter speeds, which means you 00:07:38.35 --> 00:07:41. can stop action, like on a basketball court, in a 00:07:41.24 --> 00:07:44. fairly dark gymnasium or person up in a stage play, 00:07:44.32 --> 00:07:47. that's walking back and forth on stage that doesn't 00:07:47.01 --> 00:07:47. have a ton of lighting. It's going to enable you to potentially use lower isos, which improve our ing image quality, of course. We can shoot under those lower light situations. It enabled us to shoot with shallower depth. The field, which is going to be very popular for you. Portrait photographers, of course. One of the other nice things about an slr is that you get to look through the actual lens that you are shooting, the brighter. That lends the brighter the viewfinder and the easier to see your subject. It also allows for a little bit faster focusing because the more light that comes into your camera that's more light for the autofocus module of your camera to drive the limbs has just kind of a side benefit usually these lenses have faster focusing motors in them as well and so that kind of a bonus of that feature and this is kind of another you know, side benefits not directly with fast lenses but in general these were their higher in lenses they tend to be better quality constructed and they often times have a little bit more more features that they're going to offer you in the particular lands and so these air really some of their highest in lindsay's we're going to talk more about some of the specifics in our third section, which is on features and technology but this is kind of a quick overview of some of those things that you're getting in those fast lenses can I see you have a question? Maybe yeah, I do it this is from billy bateman and it had a number of votes on it, so the question was are faster lenses the one point to one point four it's that are usually sharper then a four for example, his sharpness coming to play sharpness is a big part of this and we're going to be talking about sharpness in particular in the features and technology section because we couldn't talk about how you design lenses and in theory they're all sharp I mean they don't design blurry lenses but they're all designed to be sharp and the prime lenses tend to be sharper than the zooms but this is just in a very general basis but there's a lot of things involved and we will be discussing that actually in this section 00:10:02.98 --> 00:10:08. so wait check my notes so maximizing sharpness coming 00:10:08.34 --> 00:10:11. up here in a little bit great and then with regard 00:10:11.91 --> 00:10:16. teo again the fast lenses are they better focusing 00:10:16.07 --> 00:10:18. lenses which you mentioned because they let in more 00:10:18.56 --> 00:10:23. light for the cameras focusing system that is a generally 00:10:23.49 --> 00:10:26. true statement for instance that was from and we really 00:10:26.76 --> 00:10:29. don't want to talk about cameras do we will talk about 00:10:29.85 --> 00:10:32. for just a moment so on some of the canon cameras 00:10:33.29 --> 00:10:36. they have auto focusing modules that work with all 00:10:36.83 --> 00:10:39. lenses that are five six or faster and that is the 00:10:39.39 --> 00:10:42. entire lineup of cannon lenses but some of the cameras 00:10:42.79 --> 00:10:45. and I'm trying remember off the top my head five mark 00:10:45.26 --> 00:10:49. three have special sensors that work on ly with lenses 00:10:49.49 --> 00:10:52. that are two point eight and faster and it's a high 00:10:52.46 --> 00:10:54. precision sensors so if you put on the lens it goes 00:10:54.49 --> 00:10:57. to two point eight it's enable it enables that lens 00:10:57.68 --> 00:11:01. to focus more precisely and that is exactly when you 00:11:01.45 --> 00:11:03. need it because if you're focusing 00:11:04.85 --> 00:11:08. on my little water here with an f four lands you got 00:11:08.75 --> 00:11:11. a little bit of slop room in here where you got maybe 00:11:11.21 --> 00:11:13. four or five inches and focus but when you're focusing 00:11:13.36 --> 00:11:15. on a two point eight lands you might only have one 00:11:15.85 --> 00:11:19. inch and focus and with that faster lands on that 00:11:19.57 --> 00:11:21. particular camera and it varies from camera to camera 00:11:22.14 --> 00:11:25. enables that lens to focus a little bit more precisely 00:11:25.61 --> 00:11:28. and so kind of that that the critical numbers that 00:11:28.59 --> 00:11:31. you need to remember is five point six is which you 00:11:31.32 --> 00:11:33. need on your lens and so if you find the lens that 00:11:33.54 --> 00:11:36. is an f eight lands it's either not going to focus 00:11:36.67 --> 00:11:40. at all or focus very poorly one of the lenses that's 00:11:40.25 --> 00:11:43. quite popular in the market right now sigmund tamron 00:11:43.16 --> 00:11:46. are making a one fifty two six hundred that ranges 00:11:47.75 --> 00:11:49. I think it's three five three five but it goes to 00:11:49.62 --> 00:11:53. six point three and I hear that I'm like wait a minute 00:11:53.26 --> 00:11:56. that's beyond the five point six range how is it going 00:11:56.43 --> 00:11:59. to auto focus and I haven't had a chance to test that 00:12:00.35 --> 00:12:03. but it will probably still auto focus but it's it's getting weak because the general limit is five point six and when a lens goes to two point eight that's the other key number because I know that's where you that's kind of the extra threshold for getting into that extra performance on focusing on most of the cameras as they will have a high end f two point eight and I have that all clearly outlined in my camera classes as I go through the focusing module in it, but that's on something like the five d mark three and even on the seventy mark to, for instance, cool. Thank you. Okay, all right, so these lenses three, five, two, five, six. This is the vast majority of the basic zoom lenses on the market with cannon and the reason that you're going to want to buy one of these is get they have a very versatile zoom range on them. Another good reason is that they're less expensive than these faster lenses that we're going to talk about in a moment. They're also going to be smaller and lighter. This little ten to eighteen is just it's, a featherweight it's super lightweight with one hundred, four hundred it's, still a pretty big, heavy lens. But it's, a very versatile zoom range that would be impossible in a faster aperture at this size. Now the types of photography I imagined doing with these types of lenses is it's, pretty good general purpose stuff. And so this is where most photographer start out, you know, this eighteen to fifty five that's, essentially basically where I got started, it was a thirty five to seventy back in the day because we were using full frame film, but in this case, you know your basic simple range, slow aperture, general purpose, family photography, travel, photography is going to be fine for this sort of thing because of that versatility, less expense, smaller and lighter. Those are all really good things for these types of photography. All right, let's, try the next one f four cannons brought out a lot of f four lenses. These didn't exist twenty, thirty years ago, and it really, really happy to see these because compared to the two two point eight lenses which are coming next, which are, you know, kind of a favorite of the pros, these are many cases much more affordable than they then the big brother two point eight, they're lighter, they're smaller. And the zooms stay at f or it's really nice when you set up a camera you set up all your manual explosions you get everything set just the way you want and you decide you know what I want to zoom this from seventy two, two hundred and I don't want to change anything else on the cam I don't wanna have to go change my shutter speeds just because I zoom and so this is great for people who are doing manual exposure photography because you don't need to re calculate things when you change the zoom you could just do the exposure and then you can concentrate on composition and getting the shot and they have a wide variety of lenses that actually go all the way down from eleven up to four hundred in the f four zooms and so I would imagine we have a lot of people doing travel photography little bit of wildlife photography this two hundred four hundred kind of a special lens will talk more about it later very good for landscape photography landscape photographers they're not shooting at one point for in two point eight for most of their types of work f four is more than enough and that lighter smaller size is perfect for this and these air often just a sharp sometimes even sharper than the two point eight zoom lenses that we're going to get to next so I'm a big fan of the air force the two point eights, though, are very popular for people who are very serious about what they're doing and usually want the cutting edge top of the line. Let in the most light possible. And so this is a very common number for the fastest aperture possible of any particular lands, which is going to allow us to shoot faster. Shutter speeds have shallower depth of field for separating our subject from the background. And the zoom stay at two point eight which is nice because it's a consistent aperture it doesn't change on you and so if somebody said I just got a job as a professional photographer doing in almost anything and I need to buy a bunch of lenses what should I buy so well you should probably buy twenty four seventy two point eight seventy two two hundred two point eight and you'll probably be good for your first couple weeks of work until you figure out exactly what you're doing those air just good general purpose very professional lenses and so the types of photography that people are going to doing with this action photography sports dance anything where you've got a lot of people or animals or things moving around a lot event photography we're talking about weddings or a corporate event or gatherings or any sort of group event where you got a lot of people moving around maybe in dark environments and just people tend to move a lot and so you're going to need ah faster aperture so that you can use a faster shutter speed and if you do that a lot that's what you're going to do here and so a newspaper photographer news photographer is going to probably want to seventy two two hundred it's versatile but it's also very fast the f four is lighter but that two point eight aperture is a whole doubling of the shutter speed and that's critical in certain types of situations, and so different lenses for different types of purposes. Now there are lenses that go down to one point two two f to these are going to be prime lenses you're not going to find zoom lenses at least from cannon sigma just released a couple of lenses over the last couple of years that are faster than to point a we're going to get to those when we talk about the lenses in particular yes I have no problem talking about him because sick is making some pretty awesome lenses these days but for cannons lenses right here one point two to two we're talking about prime lenses anywhere fifty eighty five two hundred millimeter fashion or speeds shallow depth of field as I said these are going to be working under very low light conditions so if you knew that you were always working at the university under really low light conditions and you your job was to go out and shoot regular pictures you might need a two hundred half too and that's just the only way to get your shot and so event photography could be portrait's because portrait's like that shallow depth of field probably one of the more popular lenses for the sports illustrated swimsuit edition would be this two hundred f two out on the beach they got a big open area they wanna have their subject and really sharp focus in the background really, really blurry that's probably I don't know for this for a fact, but it's probably whatmore covers of sports illustrated in the swimsuit edition have been shot on than any other lands. So any sort of low light action.