Lessons

Lesson Info

Light Output Compared

we're about to do something that's really, really fun. I am going to show you a bunch of different lights and we're going to attach different light modifiers and we're gonna figure out which one gives us the most bang for the buck, what which one is the brightest light? And then in the next segment we're gonna do something even more fun. And so to help me illustrate this, Teresa is gonna come out and she's right here, come on out, Teresa. She is as you can see in some groovy workout clothes, so she's dressed like this because after we figure out which lights are the brightest, she's gonna be doing some jumping and crazy stuff in mid air and we're gonna try to freeze that motion. But before we get there, we have to figure out which lights are gonna give us the best results. And so let me show you how I have everything set up. So Theresa, if you'll zip over here, we have a light meter on a stand. So right here there is a light meter and this is going to measure how much light is coming f...

rom these lights over here on this side. And so to show you we have, I have different lights and different light modifiers. So, I have the least powerful light. This is a forsa 60 B. It's a little guy usually used for like Close up interviews and things like that. It's an awesome little light. And then we jump up to afford 200, much more powerful for its a 300 even more powerful. And then 4, 500, this is the big gun packs a lot of punch and so what we want to do is to compare exactly how much brighter these light skin because we know they are going to be brighter. And then also we have hard light reflectors on there that will give us a lot of punch. But I want to see what happens if we start adding this guy right here. This is a final lens so that should theoretically give us even more light, more uh more light is traveling to our subject. So let's figure this out. So between this bar right here. So I've set up this light stand with a bar and this is going to be our starting line. So all the lights will be above this. So we have equal distance. So I'm gonna give this to Theresa, she's just gonna put that to that light meter. So this is 10 ft exactly. So we have 10 ft from this light bar right here to our light meter. Now that light meter is going to be measuring a value called lux And then I'll also flip it back and forth so we can see some things like shutter speed and aperture value to translate what lux means in photography terms but think of lux like temperature and so it's a relative measurement, you have to understand what lux is measuring just measures how much light so a higher number means more light and then we can translate that into shutter speed and aperture values and things like that, but we're gonna stick to lux to see which is brighter and then once we get to the brightest we'll see exactly how bright that is now. Speaking of bright, if you look at this giant studio right here, we've got our giant studio camp, we have lots of light bouncing everywhere, I don't want that light to influence our meter reading, so we have to somehow make it dark in here and that's what we're going to do. So if we look at the entire lighting system here, we're gonna start shutting off the front lights. So those guys are turned off, then we're gonna turn off these two lights right here. So those guys are turned off and then what we have done is this light right here has a grid on it, so it's restricting the light so it's just a pool of light right here. So the light is not going anywhere else. If I go over here you can see I'm in darkness, there's no light there and then this light right here also has a grid that's restricting light and so it's so you can see what I'm doing over here, but if I go over here, you can see that where the light meter is, it's dark. Oh yes, I'm stepping on stuff and so none of the light that we have on right now is hitting our light meter and we have done that intentionally so that you can see me, but we don't have to have this in light. Em pollute this, those are the words I'm trying to use to pollute. So Teresa is gonna help us with this meter reading. And so what she will do is she will push that meter reading button and what has to happen first is Mark has to turn on the meter, so that will come on, this is our psychotic and there you go. So she will push that and it will give us a value in lux. So right now go ahead and meet her forest Theresa she meters that and that's metering at 46 Lux, that's just not very much light. Okay, so now what we're gonna do here is I'm going to bring up our first light. So his first light, we'll get this sort of a closer shot of this. This is a forsa 60 b. This is the little guy that we used before and to keep things fair, I'm gonna try to put the front of the light where are light bar is so it's the front of the light, that's at 10 ft, not the front of the light modifier. So it's about right there. So this is the light that should give us the least amount of light because it's the least powerful light and so it's 60b and it has a soft box on it. And so traditionally soft boxes diffuse light and they absorb a lot. So we're not gonna see this is gonna be the least powerful light. So what I'm gonna do is when you turn this on This light is set to 100% value, colour temperature is 50, and so let's go ahead and meet her that. And when we meet her that 150 Lux, 150 lux, what does that mean in terms of photography? So, I'm gonna go over here and do some fancy things to this light meter. I'm gonna change the mode so that we have this in shutter priority mode. And so when I meet her this now we can see that if we were taking pictures at 100 and 25th of a second, I S 0 800 that that would meet her at 1.8. So it's not a lot of light, we'd have to have a high I S. O and a really wide aperture value. So that is how that lux translates into photography. So 100 and 40 lux not a lot of light. Okay, and that's at 10 ft. So now what I'm going to do, so I'm gonna turn this guy off, I'm going to take off this soft box, I'll put that on the ground and now I'm going to change to a standard, this is a standard modifier, you can see that guy right there. And so this is going to its parabolic which means that it focuses the light and shoots everything out straight. It is a really efficient light modifier, Somebody turn that on and then I will Again, it's a 100% to make sure this is right out. There you go, very much its a lot brighter now. So let's now meter this light. So go ahead Teresa meter that. So we just went to 970 Lux what? That's a lot brighter. So what I can do is again, let's take a look and see what that translates into. So that's a 45. So we just went from 18245 and so that is what two stops about two stops um a little bit more than two stops of so that's four times as much like it's a lot lot brighter. Alright, so that's what this this modifier does for us. Let's go and try something else. So now we are using this guy just gonna pull go back to my pool of light. This is a final lens. So I will put this on my head here and I'll turn that on And it takes a second for this to turn on 123 and it's on boom. Okay, now this final lenses is zoomed out right now so it's not focused but when we meet her this we get how many lux? Oh I got to change it back to lux. So it went down by just about a third. Stop there. Somebody change this back into lux. So we have a relative measurement. So 640 Lux. So not as bright. But what I'm going to do is I'm going to zoom this light in so it's very focused and now meet her that one more time, wow, 2400 Lux. And so that translates to, let's see. F seven. So What did we learn? We learned that this 60 be here went from a value of 1.8 to what was the last value 7? Is that right? Yeah. F 77. Yeah, so 1.827 is just an incredible range of light and we did that only by changing our light modifier. And so definitely the final lens is what works best. And so now what we're gonna do is remember that lux was 2500, I think that's what we were at. I'll come back over here. I'm gonna change this back to lux. There we are. 2400. So that's what that's what we want to beat. 2400 is the record at this point. So I'm gonna take this light, move it out of the way and now what I'll do unplug this just so it doesn't tangle me up and now we're gonna go to the forsa 200. This is the force of 200. We're not gonna mess with the soft box because we have already looked at that. This is gonna be very bright Teresa so prepare yourself. All right. So now We're going to put this at 100% and meter that for me please. And that meters at 2600. So 2600 is what this guy pumps out without a Fresnel lens, which is pretty impressive. So you can get more light out of this with a standard reflector than you can with their 60 b with are really impressive reflectors. So what I'm gonna do now is let's try what will happen. So 2600 is where we were at. So now I'm gonna put on a for now lens and this one is zoomed out so zoomed out what is the value there? We're gonna meet her that We went from 26 26. No change now I'm going to zoom in on this so I am really focusing the light and now what do we get there? 5000 what? Okay, so we keep doubling. So that went to 5000. That is the record. That's what we want to be so far. So in the nand light 4 to 200 we have a 5000 lux at 10 ft. That's pretty impressive. That's a lot of light. Okay, so now let's keep moving up So you can see right now we could be shooting at aperture values of seven or 10 something up there. So we have plenty of light to do what we want. But let's see if we have a motion freezing light because we want to be shooting at much faster shutter speeds. We want to be shooting it 8,000th of a second. Okay, now we're at the four is a 300. Okay, so full blast force of 300 with a standard reflector is 4200, so not as bright as the final lens on our other uh on our force a 200. So what we're gonna do is let's put the final lens on there. So let's see yeah, how far we get. Okay, so this is the final ins zoomed out and that gives us 30 600. So we're going down a little by spreading that light out, we're gonna zoom that in and now that guy is 12,000 as a lot. Okay, so just so we are clear on what the heck 12,000 means? Are you blind? Yeah? Okay, I'm blinded S. F. 16, It's 125th of a second and I also 800 f. 16. So that's what we've come from 1.8 two F 16. That's a little big big difference. Okay so we have one more light to check and let's see what we can do with that. So I'm going to take this guy off And we're gonna go to the big guy, the force of and we will see what that does for us. Unplugged this guy All right, one more light. Let's see if we can get up to big big numbers standard reflector. Let's see what it will be. I have no idea what it's gonna start at, but I'm gonna guess. I'm gonna guess. 12,000. What are you going to guess? Mm Teresa guesses 11,000. Teresa guesses. 11,008 m at 6300. We're both wrong. Oh, you both lost big time. It's pretty crazy that the final lens makes that much of a difference. So, I'm gonna put the final lens On the big force of and now we'll turn that on. So it zoomed out right now. So that meters at and now I'm gonna zoom that in. What was it? It's totally zoomed in and that meters at 18 0 lux and that translates into real life values of F 20 At 25. So I don't even have a lens that goes to F- I don't think. And so I could go up in shutter speed and get my lens. So the 5/100 of a second. F 10. That's pretty good. I could shoot at 5/100 of a second is oh 800 F 10 10 ft with that. Okay, so what we're going to do now Theresa come on out and we're gonna have Hannah turned back on the lights so that you can see us in real life. And what we're going to do is now that we know that what we need Our um I'm gonna turn this off so we don't keep frying us. What we need are uh these big guys right here, the force of 500, we know that it's gonna give us the most light possible. We know that we want the final lenses and we want to zoom those in a little bit so that we get nice coverage of light and then we need you to go and do some super Wonder woman stuff and we'll capture that in um in our camera at a high shutter speed. But if you saw we can't shoot at 8000 of a second, we need to do some things. And so in the next section I'm going to explain how we get there.