Aperture: Hyperfocal Distance
Okay. Next section is hyper focal distance, one of my favorite words, cause it sounds like you're really smart. Hyper focal distance, so hyper focal distance is the focusing distance to achieve the maximum depth of field. So we want a lot of things and focus. Where do I need to focus? Should I focus at two feet, three feet a meter, 10 meters? Where do I need to focus in order to get as much in focus as possible? In general, this isn't exact. I know this, but in general it's 1/3 in front of where we focused and 2/3 and back, which means in many cases were getting a little bit more behind where our plane of focus, where we focused our lens than in front of it. Now this is also according to focal length aperture and are subject distance. This is going to kind of play. Having this about 1/3 2 3rd is most of the case. When you get focusing up really close, it's more 50 50 and so it's more in a general range. It's 1/3 2 3rd and close up. It's about 1/2 in front half in back And so what this ...
means is that we're gonna focus at a particular spot in this case on the number 10. Okay. And if we choose a very shallow depth of field, it doesn't really matter what number we're not worried about numbers, but a shallow depth of field. We might have one inch in front and focus and two inches behind it. That's what we mean by 1/3 in front, 2/3 and back. We stop it down another aperture. We now get two inches in front and four inches and back, so there's a little bit more behind than there is in front. And so we can continue this down the scale, always having a little bit more behind than we are in focus in the middle. So we're more behind than in front. Excuse me. So we go all the way down to the smallest aperture. F 32 depends on the last, and we're trying to get everything in focus and you see that red infinity symbol up there. We want infinity and focus. So what do we do? Well, here's the mistake that a lot of people make is they go well I want infinity and focus, so I better just focus on infinity. And what they've just thrown away is all that depth of field that is on the other side of their focusing point. What they should have done, if they could see, is to move the focus point back just a little bit. So the back edge of that focusing lines up with infinity. That way you get from infinity all the way down to the foreground in focus. Now, this is not so easy to do in the camera because you don't get to see these lines. You don't get to see where the front edge in the back edges focused. So let me do one more visual example just because I like to do on a visual examples, I don't know why. All right, so you got the mountains, you got the flowers. You want everything and focus. If you focus on the mountains, what happens? Well, if you have choosing aperture like 2.8, just the mountains are in focus. The flower is not in focus. All right, You said F 22 because you want everything in focus. Well, maybe that f 22 does not reach those flowers in the foreground. So you decide. Well, let me change tactics. I'll focus on the flowers. Well, as you focus closer, you get narrowed up. The field on that F 22 is likely not going to reach all the way back to the mountains. But there may be a secret spot right in between, where it matches up perfectly and stretches forward to the tulips and backwards to the mountains. And you get everything in focus and you get exactly the shot you want. But you need to be able to figure out where that focus point is, which is always a bit of a challenge. And so photos that exhibit hyper focal distance are images with everything in focus. We have a pillar in the foreground, which is in focus. We have columns and arches in the background, which are all in focus. This is, ah, hyper focal shot because everything is in focus. Another good example. We have a subject in the foreground. We have subjects in the background. They're all in focus, very common technique for travel photographers and landscapes where you want to get everything in sharp focus now in order to do this. It helps if you have lenses that have good information on them. One of the things that I really like and I think all my lenses have is a focusing scale, a distance focusing sale so I can see where my lens is focused at him. I focused at infinity or one meter. The other thing that I know. It's nice to have an L on current lenses. It's terrible. It was much better back in the eighties when we had manual focus lenses is the hyper focal scale on the bottom, which shows you the range of what is in focus. And here on the 24 these air two different 24 millimeter lenses. Okay, the scale is much more illustrative here on the 24 14 than it is on the 24 to 8. Now they're different size scales because the size of the focusing ring is different in the scales. On their different. Both 24 is exhibit the same amount of depth of field, but the scales are different because the mechanics and the lens are different. Now this is a like a lance, and this is a depth of field scale that I really like. This is good stuff here. This is the way I wish all lenses work and those cheap lenses. Ah, photographic crime. No focusing scale at all. Alright. How does it begin? Are gonna learn about focusing if they don't even know where their lenses focused out. But they do this to save money and save white. And so you're gonna find that on the lower lenses? No focusing scale. And so I very much like a focusing skill. And so here we have our focusing scale. We can focus from an infinity down to two meters or about seven feet. In this example. This is what I wish our lenses look like. Okay, This is not an example from a cannon lands. I don't own this lens. If I created a lens, this is what it would look like. Okay, so we're focused at two meters. Let's focus at three meters or 10 feet. And if we were to set F 11 on our camera, you can clearly see exactly where those blue lines extend to. I'm focused at three meters. I'm set to F 11. That means I get everything from two to five meters and focus. All right, let's try it at another area. Let's go out to infinity. All right, here's our infinity Mark. We're still at F 11. What's in focus? Everything from about 10 meters to beyond Infinity. What's beyond infinity? Well, there's nothing here and so we've kind of wasted this area. And so if we want infinity and focus and something as close to us as possible at F 11 we would readjust our focus. And what we I would mainly be looking at is this F 11 line lining up with the Infiniti mark because I know that's where my limit ISS and then I would find out. How far does that stretch into the foreground? Now? What if I want as much and focus as possible at any aperture? I would line up the 22 with the Infiniti mark and I would see down here on the left that it would come all the way down to two meters and so in this theoretical case, I could get two meters to infinity in focus at F 22. If I chose in F 11 here, I'm only going to get from three meters to 10 meters in focus. And so if you have this scale on your lens, it's great to have. But this varies from camera or from lens to lens as to how good this scale is. And typically on most modern lenses, it's terrible. It's absolutely terrible, even on the best lenses. It's terrible. You're gonna You're gonna find this. It is gonna be better on whiter angle lenses because they tend to have more depth of field. It's It's non existent on telephoto lenses, for the most part. Okay, let's have a little quiz in the class, all right, so let's imagine you have a full frame camera. That's that's the default, and you have a 28 millimeter lands and F 22 which is gonna give you lots. Adept the field. Where should you focus to keep infinity and focus and get us far forward? And at this point, this is just a guess. This is just kind of your natural instinct as a photographer. Do you think you should focus at a 1.5 meters B three meters, or C six meters and will just raise your hands up? Who thinks it's letter A 1.5. Anybody who thinks it's beef, you need to focus out at three meters and see six meters and the correct answer is 1.5 meters at F 22 with a 28 millimeter lands will get us 70 meters to infinity and focus just kind of guessing most of the stuff people don't know off the top of their head. Let's try it again, though. You got an even wider lens now a 20 millimeter lens, but it's only it F 16 not 22. This exhibits a lot of depth of field. Where should we focus? 0. meter or two meters? So who thinks it's a be and see? So pretty much everyone was on B and you are all correct. Nice job, folks. You guys air learning really quick. All right, so if we focus on one meter, we get everything from 47 centimeters out to infinity in focus. Let's do one more of these now. We're gonna go with ultra wide 14 millimeter lands F 22 that is going to be tons of depth of field. Do we focus at one meter 50 centimeters or 25 who thinks it's a okay who thinks it's b who thinks it's C. The correct answer is B so focusing just at 50 centimeters, which lets see 50 centimeters. I'm thinking it's about that far. Right there. You'll get everything from 19 centimeters all the way to infinity. So if you want lots of depth of field, the 14 millimeter lens is going to get you a lot of depth of field. Now, if you're a little confused and you're just out there taking pictures and the question you're likely tohave is all right, I got the scene all framed up. Where do I focus now? All right, so we're in this frame. Do you want to focus on the mountain now? You know you don't want to do that. Do you want to focus on the very front flour? Probably not, but you know it's somewhere in between. And that old adage that I told you at the beginning, 1/3 in front, 2/3 and back it doesn't work at all. What's 1/3 of the distance to that mountain? It's probably like appear, and that doesn't work. And so there's another rule of thumb that works out. So let's go back and review the results from our test. Okay, Now, on the 28 millimeter lands, if we focused at 1.5 meters, everything from 70 centimeters to infinity was in focus. So let's run some math on this 70 centimeters. Times two is very close to this. All right, so there is a relationship between where we focus and the nearest item in focus. Let's try this on this lens here. So when we focused at a meter, it was about 1/2 meter that was in focus. So our closest object and where we focus is about double the distance with this lands on falls off slightly. It's not the perfect analogy. We take 19 which was our closest thing in focus, and 38 was where we actually focused. And so the answer is where you should focus is double the near point. What is the closest thing in the frame these flowers down here in the very bottom edge of the frame and we're gonna focus whatever is double that distance from our cameras. So we need to kind of figure out you could bring a tape measure if you want, and you could go. Well, this is three feet away. Let's find something that is six feet away, and that's where we're gonna focus. All right? And so, in a case like this, how close is that closest subject? Inches away from the camera. So we're gonna figure out, OK, that's six inches away. I'm gonna measure and guesstimating out maybe a foot, and that's where I'm going to focus and so double the near point. So this is where you need to be very good at visually estimating distances. Another example. What's the closest thing in the photograph? The rock in the foreground at the very bottom might be 34 feet away that I'm gonna focus around six or eight feet away somewhere out there. So I wanted to think about a 24 millimeter lens. Always said, That's a kind of a good classic, Middle of wide, one of my favorite focal links. What is depth of field look like on this hyper focal with different apertures? So if you're to set 2.8, you can have your hyper focal distance at 6.8 meters, and it means everything from 3.4 meters, two infinities in focus now is you. Stop your aperture down. And as we go through this hyper focal distances where we're focusing our lands, that's what we want to focus on. And then we have our near point what is also in focus. If you stop it down to f four, we can reach closer to us and still get infinity and focus. And so I just thought it be fun to illustrate how much you're going to get in focus with different apertures and where you would focus out. And you can see in pretty much all these cases, the nearest point is exactly 1/2 the distance to where we want to focus our lands. And so what's the nearest item? And we double that distance is where we're going to focus. And so we're gonna be able to stop this lens down to I believe f 22. And so, if you want a lot of things and focus with a 24 you can focus around 88 centimeters in front of you and you'll get everything from to infinity and focus. And I thought, Well, you know what hyper focal distance looks like an F 22 on all the different lenses out there. Which lenses are good for landscape photography but forgetting for lots of things in focus? And so within 11 millimeter lens, you can get everything from nine centimeters to infinity and focus head F 22. And as you get out to slightly longer focal links, everything needs to be pushed away a little bit because you get greater white angle capability with these wide lenses. Now, as I bring up the rest of these numbers here, the numbers that I am putting up on screen right now are not written in the Bible. OK, these air not written in stone as absolute fact about where you should focus and what is in focus. And there's a whole interesting topic that we don't have time to go into. But the numbers that I have pulled from is a general consensus off what is acceptably sharp. Okay, and let's just take an example and you get the last 800 up here. Let's just take the example of the 24 millimeter lands. It is a general accepted fact that if you focused on 88 centimeters that centimeters would be in focus. But there are some pixel peepers who would say that is not acceptably in focus for me, because the size of the circle of confusion I am setting is different, and this has to do with people with different standards. And so the standards that were set that are commonly used on the focusing scales on our lenses are based on standards from the 19 forties in the 19 fifties. And so, if you rely on those focusing scales on your lens and you're not getting sharp pictures, you might think that those scales air off a little bit. It's basically because your standards have risen above the photographic standards of the forties and fifties, and there are many people who have standards that are much higher than that now. And so you're if you if you go to different websites, they have hyper focal calculators, and you can just type all this information in and get the answers. But you can set the parameters a little bit different, depending on how tight your standards are. This is pretty good general one to go by, but I just want you make make you aware that it is different and it does vary according to what your standards are. And so if you really want to get into it, there's some fun areas to dive into, and you can really go all out. Figure this out. Oh, I forgot the 800. There we go. So if you want to focus one kilometer away, you'll get everything from, ah, half a kilometer to infinity. So if you want to try to shoot everything in focus with the telephoto lens, it is darn near impossible. It's where you really need to get into these 24 16 millimeter lenses and whiter, and I think that completes my talk on apertures. Well, John, that was pretty in depth. And thank you for throwing some of those quizzes in there because I think it really allows us to kind of stop and think and really kind of think through to make sure that we're getting these things and they're sinking in. Do you guys have any questions in the studio? Are you like the folks at home who say I wish I was a nerd? My brain hurts. John's explanations are impressive, though. Yes, please. OK, John, Simple. All that in this sentence. Did I just say when I want from here, the wall and focus, I look at the closest thing and then double that? Yes, and that's where I focus. Yes, OK, Yeah. So double the nearest Yeah, and so you have fun. So let's, um I don't want to do that again. If I was to just do an example here and does this look like a flower that's flowers in the foreground? And so if I had, we'll pretend this is a wide angle lens, and so I need the flowers and focus. But I want all of you and focus. How far am I distance wise? I'd say probably three feet. And so I'm gonna need to focus out about six feet in order to find that so proud just past the edge of the carpet. And so you know, these this is this is a really rough guesstimates that you're doing in this case. And, you know, if I'm down here now, I'm a foot and 1/2 away. And so now it's even closer in on the carpet. And if you have a depth of field preview button on your camera, you can actually see this, and I believe all current current canon cameras have depth of field previous, where we can look through the viewfinder and see exactly what we're getting in. Focus a little bit more on that. Does that mean you move the little bracket in your camera? You can remove the focusing point to select something else and focus. Or you could manually focus, always encourage that.