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Fortunately, it isn't difficult to get great results from flash, and in this course, photographer, author, and teacher Ben Long details the concepts and techniques behind effective lighting with flash. Ben starts with fundamentals that build on exposure principles taught in other installments of Foundations of Photography—simple techniques that improve the results from a camera's built-in flash. He then focuses on fill flash techniques and on using flash as a key light. The course also explores topics ranging from bouncing and syncing flash to shooting with one or more off-camera flash units.
- How flash works
- Balancing ambient light and flash
- Understanding flash ranges and modes
- When to use fill flash
- Using an external flash
- Bouncing flash to improve light
- Building up multiple flash images
- Purchasing a flash
Skill Level Appropriate for all
We've talked a lot about how your camera and your flash work together to measure the light in your scene to determine how much additional flash light needs to be added to the picture. Now this is separate from the metering that's done to determine settings for the ambient exposure. If you've shot at all with an external flash or a built-in flash, then you probably already decided that, very often, all of that work that your camera and flash does is for naught, because it screws it up, and it puts probably too much light in the scene, or maybe not enough. Usually, I find that flashes are a little too over-eager, and things end up too bright.
A big part of your flash shooting experience is going to be taking a test shot, and then adjusting the flash to get the power right. You saw this earlier also that when working on a flash scene, we work with camera exposure to get the ambient light set where we want it to be, and we work with the power of our additional light to get our additional light where we want it to be. We haven't yet talked about how to do that, and we're going to do it now. It's a feature called flash exposure compensation. This is just one way that you can alter how much flash goes into a scene.
The other three ways are of course, flash position, aperture, and ISO. So, I've got a little still life here. I'm going to take a flash picture of it. I'm just turning my flash on, turning my camera on. Those are two critical steps there. To keep this easy, I've got the camera in program mode. My flash is set for ETTL mode. In other words, I'm in an almost fully automatic paradigm here. Camera is just going to do all the work for me and all I have to do is sit back and frame a shot and point it and we'll see what we get here.
want to make sure my ISO is at 100, which it is. Now, I haven't done that for any reason other than lower ISOs produce less noise. Because I'm working with a flash, I know that I'm going to have enough light. There is no reason to increase my ISO so I might as well go for the lowest noise possible. There will be times, depending on what you want in terms of your ambient exposure, where you will want to increase ISO. But here I'm just going to shoot at 100. So I'm framing up a simple shot here. Now, you can probably hear that sound, that's the flash head zooming as I zoom the lens.
So it's automatically trying to make sure that it, the flash spread is what it should be. I have pressed my shutter button, and I get a meter reading of a 60th of a second at F4. Now I'm in program mode, the shutter speed will not go below a 60th of a second; that's to ensure good handheld stability. If I was in a different mode, I might be able to control the shutter speed or I might see a different one. But in program mode, I'm not going to see it drop below that. And it's decided that F4 is where it needs to be to get the ambient exposure that it wants. And I'm just going to take my picture. And the flash fires and here's what I get.
It's actually not too far off. The flash has done a pretty decent job. Lets take a look though at what we've got. First thing you do when you evaluate a flash picture is remember that you've got two different exposures. There's the ambient exposure, that's the light in your background, and there's your flash exposure. The background is pretty dark. I'm okay with that. I like that. Our background here is just this pure white cyclorama. I like it a little bit dimmer. So I'm not going to worry about my ambient exposure. I'm going to leave it there. The flash stuff, though, looks a little hot. These white canvases over here are going out a little bit.
There's a little, the highlighting in here is just a little bit too strong. It looks like a flash picture. I would like the light to be a little more subtle. So I'm going to turn to my flash exposure compensation control. There are two ways, possibly, on your camera of adjusting flash exposure compensation. I'm working with a Canon 7D here. Most Canon SLRs are going to work this way, and a lot of other SLRs are going to work like what, what you'll see here. We'll discuss some other options in a minute. I'm going to adjust flash exposure compensation using the flash itself.
Now you should already be familiar with exposure compensation on your camera. That's what lets you dial exposure up or down to get your normal ambient exposures brighter or darker. Same thing here. I can press this button here. And I get a flash exposure compensation icon that's flashing, and it right now says plus zero, so I have no compensation dialed in at all. I had decided that my flash exposure was too bright, so I would like less flash in my picture. So I'm just going to dial this down, and just like your regular exposure compensation, it's measured in stops, so when I see here minus one third, that means it's going to cut the flash power by one third of a stop minus, oh, it keeps timing out here.
Minus two thirds, or, minus one, this will go all the way down, I believe, to minus three. I'm going to put it at minus one stop, so that's going to put out one stop less flash power than it did before. You saw a conceptual example of this in a previous movie where we had a spotlight shining on me and we just turned the power of the spotlight down. That's all we're doing here. My ambient exposure is going to stay the same, so my background will probably, mostly look the same by the time I'm done here. So, I'm framing up the same shot, metering, it still says a 60th of a second at F4, because again, my meter is just about the ambient light in the scene.
And I take my shot, and that's looking a little better. It's definitely darker. It definitely looks less like a flash picture, I'm getting less glare off the table, which is a good thing, but I think it might be a little too dark. If I look at the histogram of both of these images, I, I definitely have lost a lot of light. And where I'm worried about here is over on the left side, this area is getting just a little bit too dark. I think minus one stop was maybe too much exposure compensation. So, I am just going dial my exposure compensation from minus one stop up to minus two thirds.
So minus two thirds is actually brighter light than minus one stop. So this is going to put a little more flash light back into my picture. I am going to frame up my shot here again. Focus, meter, take the shot. And there we go. So I like this a little bit better. It's a little bit brighter. It's not so bright that it looks like a flash picture. Now, I can go the other direction also. Watch what happens if I come in here and dial up. Let's just do the exact opposite of what we did earlier. I'll go plus one stop. That's going to add one stop of flash power.
And now things are much, much brighter. Definitely too bright. But as you can see I have increased flash power by a stop simply by dialing in my flash exposure compensation. Now as I've done that, I've possibly lightened up the background also because more flash power is going to have more range. So you need to be thinking about, I keep talking about these separate exposures, the ambient exposure, the flash exposure. But there are times where depending how strong your flash is, it's going to spill into other parts of your scene and affect your ambient light. It's not affecting it so much that I am worried about it, it's not a problem here.
But sometimes that kind of spill between the exposures can be an issue. Now I am adjusting exposure compensation here by doing it on the flash. I can also, in this case, control flash exposure compensation from the camera. I'm going to set this back down to zero. And if your camera offers flash exposure compensation onboard the camera body, you might find that that's an easier way to dial in flash exposure compensation. On a Canon camera, I just press my flash exposure compensation button, which has the same icon that it does on the flash, and then I can just turn a knob down here, and it will update flash exposure compensation.
If you look in your manual, you'll maybe learn some interesting things about the interaction between flash exposure compensation between the camera and the flash. In the case of a Cannon camera, or at least this Cannon camera, I cannot use this control if this control is set to anything other than zero. In other words if I had any flash exposure compensation dialed into the flash, my on-camera flash exposure compensation control won't work. If I dial in down here, say, minus one stop of the flash exposure compensation. And I have zero up here, then I'll get my minus one stop.
If I now come in here and dial in say minus one third stop, that now overides this. They do not stack. They're not cumulative. I've got minus one dialed in here. And minus one third dialed in here. My picture will be minus one third. The flash always overrides what's on the body. Your camera maybe completely different. You just gotta check your manual. I looked in the index for the Canon manual under flash exposure compensation, and there was a little note that explained it all very clearly in just a couple of sentences. This is a critical feature. We are going to be doing most of our flash balancing work with flash exposure compensation through the rest of the course.
It's where we will spend most of your time manipulating flash. You've seen my process here. This is a great thing about digital. I can just explore. I can take a shot, I can review it. I can look at my histogram. If I've got too much flash power, I can dial it up and down with flash exposure compensation. Now, normally, I might also be worried about my ambient exposure, and manipulating that separately, as we've seen. But in this case, my ambient exposure looked, fine. So before we go on, go to your camera, find the flash exposure compensation control, learn how to use it.
If you're working with an external flash, try to look up in your manual the balance of the controls. Whether external flash overrides internal when, speaking of flash exposure compensation controls. Again this is a critical tool so you need to know how to use it before we move on.