The Technical Trinity
I call it the technical trinity because I think these are the three elements that are most important about photography. All right, you've got your aperture, shutter speed, and ISO, and, now that you know the drill to use to find out where those are on the camera, I'm going to tell you what they mean and what they do. First of all, aperture is governing the amount of light. The shutter speed is governing the duration of light, okay? And then ISO is the sensitivity to that light. It's pretty much that simple. So, what you want to do is you want to understand that the aperture is going to change in size, I'm going to talk about that in a minute, and that the shutter speed is going to create the duration, and the ISO is the sensitivity. They're all inter-related, and so it's basically cause and effect. What you're going to end up doing to maintain all these issues when you change them is you're going to control not only them but you're going to control things like the depth of field, the t...
ime, the dynamic range, and that's usually deals with digital noise, detail and color, and then finally your camera stability, which depends upon the shutter speed. So, all this is based on a theory around a stop of light. You've all heard that term, well, it's basically a stop of light is equal to itself. So what you have is if you take an aperture for example and you change it from F/8 to F/11, you're subtracting a single stop of light. Same thing with the shutter speed, a quarter of a second to an eighth of a second, you're subtracting a stop of light. ISO, 200 to 100, you're losing a stop of light. Opposite, you go from F/11 to F/8, you're actually increasing a stop of light, okay? It's the same thing, just the opposite, plus and minus a stop, basically the general idea. To maintain accurate exposure, once you move one of them, in this case the shutter speed, then you have to counter that with one of the others, okay? So if you up your shutter speed, then you have to decrease the amount of light with the aperture or the ISO. Either one, you have to change one or the other to maintain that accurate exposure. Same thing with more, you add two stops of ISO, now you can take away one stop of aperture and one stop of shutter speed, all right? Or you can take away two stops of shutter speed. Those are the decisions that are hard, though. When do you do each one of those? So, one of the things I ask people to do is to look at those numbers and memorize the apertures. You know, it's another drill, but it's not that hard. I know you guys speak multiple languages and you have all kinds of things that you want to look at, but this is number one. In the rest of your life, you're going to memorize those numbers, but the reality is you don't have to memorize that many, okay? So most lenses are going to have a range from F/4 to 22, and those are the critical numbers. I should point out also that these are the full stop increments, and a lot of your cameras are set to third of a stop increments. So when you're looking at the back of your cameras, and you're turning the dial, the aperture dial, from 4 to 5.6, you're going to see some other numbers and those are the increments between that full stop. And also, just to note, I actually change my camera and I override it so that I only have half a stop increments mainly because I don't want to click so many times, but also because the difference between a third and a half a stop is minimal. I'm not really concerned with that small of a difference. A fast lens, goes from F/2.8 to 22, so we just gained, the reason they call it a fast lens, is because you have a faster shutter speed because you're letting in more light. That's what that aperture's doing, from going from 4 to 2.8, it's allowing more light to come into the sensor. A really fast lens is when you get 1. and a stupid fast lens is F/1, and those are far and few between. They do make them, but I think traditionally most of us would agree that the fastest lens we own is a 1.4. Now for night, just to point out, the 1.4 lenses are really optimal because they're letting in that much more light, all right? So memorize these numbers, typical numbers though for most lenses are F/4 to 22. The other numbers past 22 are actually for the old four by five lenses. Some lenses have F/32 but very few. All right, so the next thing I want to talk about is how to perfect the scenarios that I just discussed. Why you would change aperture and shutter speed, not ISO, or vice versa, and then, in order to do that, you have to understand the digital file. So that's why I bring both up. Way back when, in the dark ages, before we had digital, we did have light meters, but we also had the old Sunny 16 Rule, and I'm sure maybe some of you have heard this, but it's really simple. In the daylight, you're going to get a great exposure at F/16 if you match the shutter speed and the ISO. So 100 ISO, 100th of a second, at F/16, you will get an exposure in the daylight anywhere around the world, the daylight doesn't change. As long as you're not using a filter and it's not cloudy, so you can remember it also by here, maybe in Seattle, it would be the Cloudy F/11 Rule, (audience laughing) which allows in a little more light. All right, so then there was the meter in the digital age, and the meter nowadays is nothing other than a chart, and it's called the histogram. So that is what we use now, or that's what I use now for my meter. They still do make really fancy meters, spot meters, and, if you're working in a studio, that can be very helpful, but essentially I can look at a histogram and know right away if my meter's on or off. So what happens in a histogram? Basically the left side of the histogram is representing the black or the darkest values, the right side of the histogram is the brightest or the white values, and the number scale, I'll bring up again more again and again, is that it goes from zero, which is a black, to 255, which is a white, okay? And the reason there's three of them is that there's three colors, red, green, and blue. Your histogram will change, in this case, you can see that it's changing position, and it'll also change in color, because the one on the left is a color file. The one on the right is a black and white. But you can see here, where it's separated, that's representing the different colors in the picture in different areas and different regions of density of those colors. Don't worry about where that histogram is, okay? These are perfectly exposed files, but the histogram's all over the place, but that's how they should look. What really matters are the very edges, because that's what's giving you the information that's most important such as the information that's not getting recorded on the sensor. So, right here on the black side and the white side, that's what we're going to show some examples of. This is a picture on the left that has quite a bit of contrast, and you can see the histogram on the left is what's called, crawling right up the left side of the histogram, and that's because all that shadow detail is now black, and there's no more detail in it. On the far right, same thing's happening. That's this blown-out sky, as I call it blown out, because that's because there's no detail in it. That's what the histogram's showing. Histogram's spiking up the right side of the chart, therefore it's telling you there's no detail there. The one on the right is just a low-contrast scene, so you don't have to change anything with that shot to get a good exposure. You don't have to get the histogram in a certain spot except for one scenario which I'll explain in a minute, but that's just because of the amount of light that's striking the subject. The histogram's going to be tighter and not hit the edge of your histogram. All right, so the camera options for working with these different aspects are mode, you can either use Manual, Aperture Value, Time Value, Program, or Auto, and a lot of cameras have some segments in between or different options also, but those are the traditional ones. The meter is either spot, center weighted, or matrix, and at the very end is evaluative, which is the nomenclature I think Canon uses, so. Essentially, in Manual mode, you set the aperture, shutter speed, and ISO manually. You have to do physically every different dial to get the exposure set correctly. Aperture Priority is nothing other than you're going to set the aperture and the ISO, but the camera is going to change the shutter speed, so it's going to move that shutter speed up and down based on where you point the camera. And then you have Shutter Priority, which is just the opposite, only you're setting the shutter speed and the camera's moving the aperture all over the place. Then you have Auto, and there's different stages of Auto, but basically that's going to be where the camera chooses everything, okay? You just put it on Auto and shoot, and that's a good choice sometimes when you don't have time and you haven't done your drills, and it does work. All right, so the new technology, I just want to point this out, is that now we have things, now we have what's called Auto ISO, and so this has only been out for a couple years. It's not that new, but you should know about it, and, along with that, you have the choice of either using Aperture Priority or Shutter Priority and having the ISO fluctuate, or, if you're in manual mode, then you can lock both of those down and have just the ISO fluctuate, okay? So it's handy sometimes if you know that you have to have a specific aperture and shutter speed, maybe there's a wave coming in, and you have to compromise something, then the ISO might go up and down, okay? So a meter basically has a region of the frame that it's utilizing to take that density from. In the case of a spot meter, it's looking at about a five-degree area in the middle of the picture. Some cameras allow you to move that around, but essentially that's what it is. Then you have center weighted. Center weighted is nothing other than most of the center is what the camera's utilizing to take that exposure. And then finally you have the matrix, okay? And that's taking into consideration pretty much the entire sensor and deriving the correct exposure from information from all the shadows and all the highlights, and that's what I typically prefer. So, the new technology on top of the new technology which is the auto ISO is, in Nikon, they've introduced something called highlight weighted, and this is very handy because typically when you point in Aperture Priority, let's say, the camera at the sun, what happens is is that it probably overexposes that sun too much. Same thing happens in a backlit situation, okay? Well what this does is it takes into consideration the highlights and actually counters that by underexposing it slightly, and I've tested it. It works very well in backlit situations to preserve the highlights, okay? So it's just another option. I honestly don't know if Canon has it, I don't think they do, I've looked for it in many different manuals. My personal favorite for landscape is Manual, and the reason I teach this is so that if you learn Manual, then you understand the benefits of all the other auto settings and basically, once you know Manual, then you can operate pretty much any camera, you just know those three things and how to maneuver them, you'll be able to grab any camera. So, I love Picasso's quote, thank you, Picasso, "Learn the rules like a pro, "so you can break them like an artist." and that's what I'm going to talk about. Basically you have a couple different settings, the meter is in Evaluative/Highlight-Weighted, and then the mode is Manual and the ISO is Manual. That's, like I said, those are the settings that I like for most landscape photography. My preferences, though, for hand held are a little different, so I'm going to use the same meter reading but I'm going to change the mode to Aperture Value, and then I'm going to keep the ISO set. That's for landscapes, hand held. Then for full Auto, my full Auto, what I prefer is same meter and Aperture Priority, and then the ISO has a range of something, in this case I wrote down 200-1600, but you can change that to 100-3200 to get even more options when you're out photographing in places where it's going to go from really bright to really dark. Remember, that's kind of fun because you've locked in, your meter's working right, and you've locked in your aperture, and so you're letting the camera set shutter speed to some degree but then it'll also change the ISO as well, so you have quite a range to photograph without having to think about setting any of those other options, okay? So this is more what I would use for if I'm photographing in a place where the light's changing. Like I said, you're walking through town or hand held, and a lot of things are changing.