The Triangle: Aperture, ISO, Shutter
So we're going to still keep tearing things apart okay I want to keep tearing things apart in detail of what happens when the shutter opens and how ambient light and how flash is all exposed all that kind of stuff and so to start we're going to go even deeper okay so to start with totally forget about the ambient light okay just forget about that pretend that there is no ambient light just for a second all right so we have three things in our little exposure triangle right have aperture we have a shudder and we have isil aperture controls quantity shudder controls duration and isso controls sensitivity hey for now as we tear this stuff apart we're going to get rid of this s o stuff okay we're going to do that just like my weatherman moved did you see that that was cool I reversed that a lot so thanks for being so s so is going to go away so we're gonna talk about these two things quantity and duration think of them in those terms quantity duration how much how long all right so when we...
look at those two things remember a quantity aperture duration shudder when we look at these things duration you will find it doesn't matter the duration when we're talking about flash remember we're not talking about ambien lighting more we're just talking about flash duration doesn't matter and why is that ok, so too the shutter the shooter doesn't do squat to control flash exposure hey, it doesn't. In fact, the shutter is going to cause all kinds of problems is a troublemaker. Why is that? Remember, back here to ninja. Ok, in fact, josh, we're gonna act this out one more time. Could you zip over there? Okay, I'm picking on josh all weekend, just so you know. Ok, so shutter is closed, right? The flash fires told light from the flash in slow motion works like this hold on, not yet shuttered closed. We click the shutter release button this opens all the way up. Flash fire's light from the flash goes this way it bounces comes back so come on through here comes through okay, thanks down shutter is still open shutter still open getting ambient light still get into morning you like and then chunky closes. Okay, so what's happening is the light from the flash on lee comes through the shutter when it's all the way open, which means it doesn't really even exist. I know this is sort of a hard thing to understand and I have videos to show you this. Okay, so the shutter doesn't really matter to the flash at all. It's, like it doesn't even exist in the flashes brain so let's talk about how the shutter works normally okay, so I have this little animation here and we'll watch that and it's about twenty seconds. This is how our shudder normally works with no flash normal shutter no flash here we go when you press the shutter release with your finger it tells the camera to open the shutter the first curtain opens to reveal the light to the camera sensor then the second curtain follows behind to hide the light then the curtains reset and wait for you to press the shutter release again let's watch that again notice in this animation that the first curtain opens completely before the second crew begins to follow. This only happens in slower shutter speeds usually speeds under two hundredth of a second. Now watch what happens when we speed things up when the shutter speed is faster the second curtain can't wait for the first curtain to open all the way if it does, it won't make it across in time notice in this animation that the shoulder is never fully open it just reveals a slit of light as it travels across the sensor and the slit become smaller as the shutter speed increases okay so I forgot to tell you the shutter is made up of two curtains right the first curtain in the second curtain and they move like we just saw so there's this thing called sync speed what sink speed is it's the fastest shutter speed that allows the first curtain to fully open okay this guy's all the way open before the second curtain begins to close so in the animation we saw that the faster the shooter is these two things start moving together so sink speed is that speed where this guy the first curtain can go all the way open before this guy starts to close most cameras that is around two hundredth of a second maybe to fifty and on your cameras if you have a pop up flash or if you have a built in flash you've probably seen this you put your flash on you turn on your camera and it stops at two hundred and won't go any farther just like as it and it's doing that because of this thing called sync speed so let me explain why it stops there and why this shutter can cause problems what happens is when you add a flash to the mix things start getting wacky and so guess what I happen to have an animation all about sugar and flash I know you knew I would so let's watch this and this is that same animation but this time were adding a flash in the mix when our camera shutters feed is set to sing speed or slower a few things happen when you push your shutter release but the first curtain opens and as soon as the first curtain is fully open the flash fires then the second curtain closes normally if we have our shutter speed to high we'd have problems let's take a look when you pressure shutter release the first curtain will begin to open but before it's fully open the second curtain begins to close when the first curtain is fully open the flash fires just like it did before but this time part of the sensor is covered by the second curtain this will cause our photo have a black area and the faster your shutters feed, the more black you'll have in your photo ok, this is for studio photographers we all know this we have this problem with that sync speed because you can and studio photography you can get that you could make that mistake the camera will make you let you make that mistake with her on camera flashes the camera will allow you to make that mistake with using a sing speed that's too high so back to this shelter thing so why the shutter doesn't matter so the shutter doesn't matter because it's all the way open when the flash fires right? It is always open, so that means something to the flash the shutter doesn't even exist that has a huge implication on flash photography and that means our exposure triangle is wacky right? Because we knew three things control exposure right? I also sensitivity shudder but wait shudder just went away so we can't control our flash with their shutter I know this is like sinking and I can see it but and we also have our aperture right so aperture can control flash because it controls quantity so the aperture khun say hey not that much light mohr light so it can control that so what we're showing here is that because the shutter doesn't matter to our flash we have to invent a new exposure triangle and once weeks understand the exposure triangle for the flash that's what we're going to use to control our flash exposure and then we're going to use our normal exposure triangle which we talked about control ambient light and if you know those two things guess what uh huh now I can control ambient light and flash that's how we do it right awesome okay so I don't know I said that I said we're only talking about light from the flash right right now we're only talking about light from the flash don't forget that okay so the question is this what controls flash exposure I'm gonna let you guys guess so any guesses on what the three things are the control flash exposure to see if our people online will get so people online also guess so we already know two of them what are those apertura esa correct so what's the third thing that controls the explode the eggs explosions exposure from the flash what is that let's see online any guesses there's a little delay but famine food bar says tiny goblins tiny goblins do correct they battle the ninjas no wrong and baba ghanoush says distances subjects distance to subject uh has an impact on our flash but it doesn't control it flatters sorry saying flash power flash power beaming me correct? You said that whoever said that about your side of the head yeah, good. Okay, I'm going to call the output from the flash that's what? I'm gonna call so flash power output from the flash because guess what we can do we can tell her flash to have more light or less light we can tell it to increase or decrease we can do that which is really cool. And so what we have now is this the flash exposure triangle it's a new exposure triangle which is really cool and look, it looks just like the other one did sort of the aperture we have the flash output and we have the eye. So so let's take a look at these three things because we want to figure out something quantity, duration sensitivity, right? Those three things we still need those three things so amateur controls quantity correct flash output controls what I know it's a trick question it controls quantity and duration uh, ok, I know uh right can you see why it's so difficult to use these old speed lights or like variable after variable after variable after variable and so what? We're just breaking it down so why is this quantity and duration? Let me explain it to you our flash has something called a flash duration in other words, how long it's on josh, can I use you again? Okay, once again, josh is gonna come up, so right now you're gonna be the shutter, ok? Your shutter. All right, I'm the flash. Uh uh anybody else remember that movie? Ok, it's going to be hard for me to not dio every time I say flash, you'll save every one of us. Okay, so we're going to do here is, you know you're going to be the flash I mean, the shutter so shutter opens right? I'm the light from the flash the light from the flash turns on at maximum intensity you're still open wow a cz much as it can and it will come bounce off our subject and go through right and that might happen in let's say two hundredth of a second right? This might be opened for half a second it doesn't matter, so how long the flashes on is the duration? If I take my flash power down, it might turn on go out here bounce off the subject to come through the shudder at something like ten thousandth of a second that fast shutter is just always open so how long that flash is on? The subject is determined by the actual output of flash so not only is it how bright but it's also how long, how bright and how long that sounds like a song from camp doesn't how bride along okay, so now I did a lot of camp time sorry having flashbacks um so quantity and duration flash duration is how short or how long that light from the flashes on now the cool thing about this we will find out that you can freeze motion better with the duration of your flash then you can with your shutter let me explain that here's the flash now here's the shutter right let's say the shutter is, uh zipping it eight thousandth of a second without a flash and we're trying to shoot a baseball player, right? So it goes juke and on ly slices out eight thousandth of a second of something happening. But remember, our little flash can flash it's something like ten thousandth of a second or maybe even shorter so if the only thing that the camera sees is the light that comes from the flash weaken slice time out that these really, really small intervals and we can freeze motion better with the flash and we can with a shudder day three we have ninjas coming yes is there a day two day three we have ninjas we actually haven't interest I'm not kidding ninjas they're going to be they might already be here in the room we don't know but way have ninjas they're gonna be here we're gonna freeze them flipping around it's gonna be awesome and we're going to do with her flash and we're going to do it with slow shutter speeds and short flash rations it's really cool studio photographers and know all about this flash duration because to get short flash durations thousands of dollars really really expensive speed lights not so much okay I guess so sensitivity right sensitivity before we go on our re flooded with questions or people tracking I want to make sure that we don't go too fast for these questions well angie sense that is is wondering if you could explain again what exactly do you mean by quantity quantity? Okay quantity how much? How much so our normal ambient light when it goes through the lens the aperture closes and opens and says this is how much can go through so not very much or a lot of light quantity in the shutter says you can have not very much but it can go for really long or not very much but really short and those two things control how much light hits this sensor and gives us exposure so quantities, just how much is going through how bright quantity from the flash is not so much how much? Uh, physically but how much? How bright it is really bright. Not so bright. So I guess that's the best answer for that. Thank you. Yes, we're gonna get to start shooting pictures here shortly, so and then you'll go. Oh, god. Oh, yeah good. Yes. Okay, there's so many questions try to keep him exactly many question question that's what happened in mid life? Let's not get ahead of ourselves. Um, let's see deal from england asked what should I justify one a shallow depth of field when using a flash at the maximum sink speed? How so? State one more time? What should I just if I want to shallow depth of field when using the flowers at the maximum sing speed. So what do you adjust? So, uh, great question so you're saying is you want to shoot it one point two or two point eight to get really shallow depth of field, but you can't because you're limited by two hundredth of a second and so you're stuck, right it's going to be over exposed? Is that what we're asking, so hopefully a typing yes or no I'm guessing that's what you're asking is that you've got this issue so there are a couple things that you can do for that we're going to talk about something called high speed sync, which is magical that's coming a little bit later and you'll see that we can break through that sink speed barrier with speed lights it's something you can't do with a studio stroke so that's the first thing that we'll tell you to do is put on this thing called high speed saying that allows you to go faster that's the best um barring everything else, you can get this thing called a neutral density filter and you put that on the end of your lens and it's like sunglasses for your lens and that makes everything darker and so then you can shoot it why you're open apertures but then you have to have a lot more strength from your flash and so you might not have enough power from your flush. So the best thing to do with the speed light issues high speed sync we're not there yet we'll get there okay? So addie await that person was answering somebody else's question way to go if you know the answer answer away I love that so again on the quality duration from paul eleven isn't flash quantity on ly its duration no no so that the duration and quantity they change together but you can have a lot of light that lasts for a long time or not very much like this really short and so what will happen is you khun you can just how much of your flashes making it through by adjusting your aperture? So you gonna have a lot of light coming from this flash and you can under expose that by making an aperture to small but you can get something that's got a little bit of a blur to it because the light is on for too long. So, uh or you could dial that down. Open this up. I know fun, huh? On dso the duration is really short and you have no emotion but you have a proper exposure, so when we start shooting, I think that's going to make more sense. Ok, okay, so, um these two guys quantity, quality duration again we're not going to talk about our s o yet we're going to move on from that it's going too good. So what controls ambien exposure looking controls, the ambient exposure we have this we have shutter aperture and I am so so what we're doing here is we're saying, when you mix these two things together flash and ambient light we have eyes, so it affects both things aperture effects boast both things shudder on ly affects the ambient light so you can change your shutter speed up or down it's going to change your ambient light. It's going to leave your flash alone?