Latest / Wildlife and Adventure Photography / Exposure Compensation: Take Control of Your Exposure
Transcript
- 0:08SPEAKER_00: Hello again and welcome to today's podcast.
- 0:10SPEAKER_00: Now, I want to talk about exposure compensation and um just talk a little bit about what it is, what it does, and when you use it.
- 0:17SPEAKER_00: So if you don't know what exposure compensation is, you might have noticed on your camera somewhere, um, if you're using a DSLR or mirrorless um uh type camera, there's a little button with a plus and a minus on it.
- 0:30SPEAKER_00: And also you might have noticed either on the information screen on the back of the camera or through the viewfinder, there's a little scale with a zero in the middle, and it goes from plus one to plus three on one side over to the right, and then minus one to minus three on the left-hand side of the zero.
- 0:46SPEAKER_00: So this is your exposure compensation um scale, and it's actually useful to know about because I've always found it's one of those controls I'll accidentally reset and then my exposure's all off, and I'm trying to work out what I've done.
- 1:03SPEAKER_00: Where you're gonna be using that is in a situation where you've taken a photograph and you've checked the image on the back of the camera and it doesn't look right, it's too dark or it's too bright, and you haven't done anything wrong, and you've allowed the camera to make the exposure decisions.
- 1:20SPEAKER_00: So you might be using one of the modes, I'll dive into those in a moment, but but the camera's got it wrong, and the reason is simply that the camera is programmed to expose to a particular level, and a particular gray scale, in fact, is what it's exposing to.
- 1:39SPEAKER_00: So, on the whole, that works pretty well, but there are occasions where the situation that you're looking at fools the camera's exposure uh meter so that it actually gives you the wrong exposure, or your subject is in a situation where it kind of gets lost.
- 1:58SPEAKER_00: So, what you need to remember is the camera doesn't know what your subject is, it doesn't know what's important in the scene, it doesn't know whether the white object that you're pointing it at is supposed to be white.
- 2:11SPEAKER_00: Uh, it doesn't know if the darkness is intentional, and it really doesn't understand mood as a concept.
- 2:16SPEAKER_00: So um it's not doing any of that.
- 2:19SPEAKER_00: That's all down to you as the photographer.
- 2:22SPEAKER_00: So, this is why I want to look at what exposure compensation actually does, and look at situations where the camera can get it wrong and what you can do to correct that, and this is basically when you would use exposure compensation.
- 2:37SPEAKER_00: So, very simply, what is it?
- 2:40SPEAKER_00: Well, it's simply telling the camera that if you use the positive scale, so you go plus one, plus two, plus three, and often you'll find um uh a sort of finer tune in between there.
- 2:54SPEAKER_00: In the canons I use, it's normally a third of a there'll be two dots between the zero and the one.
- 2:59SPEAKER_00: Um, so when you go positive, you're basically saying I want the photograph to be brighter.
- 3:04SPEAKER_00: So, in other words, the photograph as it stands is underexposed.
- 3:08SPEAKER_00: Or if you go to negative on the left hand side, you want the photograph to be darker, or in other words, you want to underexpose it.
- 3:16SPEAKER_00: Exposure compensation is measured in EVs, and plus one EV is approximately one stop brighter, minus one EV is approximately one stop darker, and this is what you'll see on the scale.
- 3:29SPEAKER_00: And then you'll have either half stops or half steps between each EV number, so between zero and one, one and two, two and three, or it might be thirds.
- 3:39SPEAKER_00: So I have thirds on my canons.
- 3:42SPEAKER_00: Um, we don't really need to go into the mathematic mathematics of it in uh this particular podcast, but that's essentially what you're doing.
- 3:50SPEAKER_00: So positive basically means you're making the image brighter, and um the negative is making it darker, and then really it's a question of finding a level, finding a setting that gives you an exposure that you're happy with.
- 4:03SPEAKER_00: What is it doing though?
- 4:05SPEAKER_00: So you're not actually changing the camera's exposure settings yourself, but what you are doing is telling the camera that it the exposure that it is creating, if you like, at this point, based on what it's programmed to do, is not correct for the situation that you're in.
- 4:25SPEAKER_00: You're not getting the result that you are looking for.
- 4:28SPEAKER_00: So, what you're essentially saying to the camera is you think this is correctly exposed, but I think it's too dark, so we're gonna go another stop.
- 4:34SPEAKER_00: I'm gonna um overexpose that another stop and make it a bit brighter.
- 4:40SPEAKER_00: Basically, um, why does the camera get it wrong?
- 4:45SPEAKER_00: Well, the camera's meter usually works on the average brightness of the scene.
- 4:52SPEAKER_00: That is not 100% correct, and I will clarify that uh later.
- 4:56SPEAKER_00: But if we start with that, just as um a concept right now, so it's looking at the average brightness of the whole scene, everything it's looking at.
- 5:05SPEAKER_00: And so if you've got a very bright image with a dark area, uh that's gonna look very bright to the camera, so it's gonna reduce the exposure because the let's say whiteness.
- 5:18SPEAKER_00: If you've got a lot of snow, it's gonna look very bright.
- 5:20SPEAKER_00: Equally, if you're shooting into dark, it's gonna try and bring the exposure up, and you might lose um a smaller subject in that darkness.
- 5:28SPEAKER_00: So it doesn't know that there's an area of white is a bird, or an area of darkness is a gorilla, it's just it's just light and dark.
- 5:37SPEAKER_00: As I've said, a predominantly white scene can cause the camera to make the photograph too dark, and what happens in that instance is whites become grey.
- 5:47SPEAKER_00: So, what you would do in that situation is to add compensation, so you're overexposing, so essentially the camera has underexposed the image because it is compensating for that that whiteness, it's trying to get that white area down to uh actually an 18% grey.
- 6:06SPEAKER_00: That's what it's trying to achieve.
- 6:08SPEAKER_00: So it's gonna mess up the brightness, the uh the uh exposure.
- 6:13SPEAKER_00: Equally with dark subjects, probably dark scene.
- 6:17SPEAKER_00: The camera doesn't realize it's a dark scene, it just realizes that the exposure it's running with right now is not hitting that um mark that it's been programmed to achieve, so it's gonna overexpose the um the image until it gets a level of grey that it is programmed to expose to.
- 6:36SPEAKER_00: So, in other words, the blacks will begin to look grey.
- 6:39SPEAKER_00: So, what you do is you add negative compensation and that makes the image darker.
- 6:44SPEAKER_00: The important thing to remember here, it's not really the colour of your subject that matters, it's the relationship between your subject and the rest of the scene.
- 6:51SPEAKER_00: So you're looking at the scene as a whole, and then how significant is your subject in that?
- 6:56SPEAKER_00: Because you might have a relatively this particularly happens when you've got a relatively small subject in a background that is predominantly light or dark, that is likely to throw off the uh the exposure of the camera.
- 7:10SPEAKER_00: Now, where I find this useful and where I tend to use it is when I'm using it with modes, so I'm a big believer in using modes, generally aperture priority.
- 7:21SPEAKER_00: So with aperture priority, you choose what the aperture is because then you're controlling depth of field, and what the camera does, it compensates to maintain the correct exposure by varying the shutter speed.
- 7:34SPEAKER_00: So that is essentially where aperture priority comes in.
- 7:38SPEAKER_00: So if you're in the situation where you have a white subject against a dark background, so let's say a white Y standing in dark water, for example, what the camera's seeing is a lot of darkness, and so it increases the exposure, and the white bird becomes too bright.
- 7:56SPEAKER_00: So predominantly, if it's metering across the whole of the scene, that scene is going to be dark because it's primarily um dark water, so it's gonna look darker, it won't be able to achieve the level of grey it's aiming for.
- 8:11SPEAKER_00: It will basically increase the exposure until it achieves a level of uh grey that it's aiming for.
- 8:19SPEAKER_00: But that as a result of that, the the bird, the white area is going to be very, very white, it's gonna be um too bright.
- 8:25SPEAKER_00: So, what you do is just try stepping down to a negative compensation, so it might be minus a third, it might be minus two-thirds, it might be minus one EV, and shoot again.
- 8:38SPEAKER_00: So the camera is still controlling the shutter speed, but what you're telling it to do is to produce a darker exposure.
- 8:44SPEAKER_00: You're basically saying, Okay, take your exposure, but I want you to underexpose it by this particular amount.
- 8:53SPEAKER_00: Now, if you go to a similar situation, but this time you've got a white bird against a white background, the camera's going to see a lot of brightness.
- 9:02SPEAKER_00: Overall, the whole image is very bright, and what it will do is to reduce the exposure again because it's trying to hit that 80% grey, that light grey kind of average um brightness.
- 9:15SPEAKER_00: So that means the bird is going to become grey.
- 9:18SPEAKER_00: So if a bird looks grey or underexposed, what you then do is do the opposite to what I've just suggested.
- 9:25SPEAKER_00: So you increase the exposure either by plus third, plus two-thirds, plus um one stop.
- 9:32SPEAKER_00: And the important thing to remember here isn't about memorizing the where you have white, you go plus, you go overexposed, uh, where you have black, you underexposed.
- 9:45SPEAKER_00: It's about looking at what the camera's doing, and then you choose based on the outcome, the result that you're trying to achieve, whether you want more or less exposure, and how much more or how much less exposure you want in order to get your subject correctly exposed.
- 10:06SPEAKER_00: Now, the other place you the other mode you might be using is shutter priority, which is one I'll use less often, but I use it quite a lot.
- 10:15SPEAKER_00: So, obviously, in shutter speed priority, you're choosing the shutter speed, the camera's changing the aperture.
- 10:20SPEAKER_00: So, this is useful for things like action photography, where you want to either freeze the action or you might want some deliberate movement.
- 10:30SPEAKER_00: So, an example of that might be a bird in flight, and you've chosen um a shutter speed of one two thousandth of a second because you want to freeze everything.
- 10:40SPEAKER_00: And in this case, the bird is dark against a bright sky, and depending on the reach you have with your lens, that bird might be quite small as well in the in the overall frame.
- 10:54SPEAKER_00: So, what the camera is likely to do is to expose for the sky and not the bird, so the bird becomes quite dark.
- 11:03SPEAKER_00: Now, you probably don't want to change the shutter speed because that's giving you you're freezing the action because that's primarily why you're in shutter speed um uh priority, you're controlling how much movement is in there.
- 11:16SPEAKER_00: So, by adding, let's say, one EV, one effectively one stop, you are telling the camera to overexpose but keep the other settings the same.
- 11:27SPEAKER_00: So the camera basically opens the aperture further, and that gives you a brighter exposure, but your shutter speed stays where you want it because shutter speed is the most important thing in that scenario.
- 11:41SPEAKER_00: And then the opposite situation is where you have a dark animal against a dark environment, and and again, when the camera's trying what it will try and do is brighten the scene, but you might want it pretty dark.
- 11:52SPEAKER_00: So again, you underexpose, you go negative minus two-thirds, minus um one EV, and what that's doing is it's not changing the shutter speed, it's just now changing the aperture settings so that you achieve that underexposure that you want.
- 12:09SPEAKER_00: So the important thing to remember here is exposure compensation allows you to retain the reason you chose the mode that you're shooting in, whether it's um shutter speed or aperture the priority.
- 12:23SPEAKER_00: It allows you to retain that mode, but it then corrects the camera's exposure um decision essentially.
- 12:31SPEAKER_00: Uh so it's choosing either the what it feels is the appropriate shutter speed or aperture to get a correct exposure.
- 12:37SPEAKER_00: Uh, but what you're doing is telling it uh this is wrong, and you need to either underexpose or underexpose or overexpose by a certain amount.
- 12:48SPEAKER_00: Another mode you might use is program mode, and um program mode allows the camera to choose um a lot of the exposure for you, it's primarily um shutter speed.
- 13:00SPEAKER_00: It it will depend on the camera.
- 13:03SPEAKER_00: When I got first used program, I didn't use it very much, but it's basically try and do the fastest shutter speed, um, or at least the cameras I used it with, which is a while back, it would try and choose the fastest shutter speed and still maintain a correct exposure, but that's you know all very iffy because um it's assuming a lot there, so you don't need to um abandon that level of automation, and the same actually applies for auto.
- 13:32SPEAKER_00: And typically, where you're gonna see this is you're photographing someone standing near a bright window, so the bright window is behind them, and that person is underexposed, they're way too dark.
- 13:44SPEAKER_00: So, this is another example where you can use exposure compensation, just push it up to plus one and see what the difference is, and what it will do is begin to overexpose what it feels is an overexposure, but it will begin to correctly expose the person standing in front of a window.
- 14:02SPEAKER_00: And this this is a probably a good way to practice with it if you're not so confident with your um camera.
- 14:11SPEAKER_00: Maybe use it in um in auto mode and see how you go.
- 14:16SPEAKER_00: Um, another thing you can do is auto ISO.
- 14:20SPEAKER_00: So this this is a bit more advanced.
- 14:24SPEAKER_00: Uh let's say that you are you're doing some odd life photography, your Apertures F5.6, you're using a shutter speed of one one thousandth of a second, and you've selected ISO to auto.
- 14:38SPEAKER_00: So, what you're doing in that situation is you're controlling two things now.
- 14:43SPEAKER_00: So you're going a little bit beyond what the standard modes give you.
- 14:49SPEAKER_00: So you've chosen the depth of field you want with by choosing f5.6, and you've chosen the shutter speed you want because you're shooting at one thousandth of a second, so you want to start freezing things, and the camera is managing the ISO, so obviously that's the other part, the other side of the exposure triangle.
- 15:08SPEAKER_00: But when you look at the image, you've got a consistently dark image.
- 15:13SPEAKER_00: So, again, this is a situation where you can use exposure compensation, and if it's dark, you want to overexpose a little bit, so maybe add two-thirds um EV to overexpose slightly.
- 15:26SPEAKER_00: So you're still making full use of the camera's automation, but you're correcting how what the camera is deciding is the correct exposure, you're just changing it, you're tweaking it if you like, so that the exposure is now where you want it and not where the camera has been programmed to put it.
- 15:45SPEAKER_00: So, um to recap on all of this uh a little bit anyway, um exposure compensation is particularly useful in certain situations.
- 15:56SPEAKER_00: So, for example, your subject is significantly brighter or darker than the background.
- 16:00SPEAKER_00: So I've mentioned a person standing or sitting in front of a window that's bright and they look dark, so you can correct for that using exposure compensation.
- 16:11SPEAKER_00: The camera consistently makes the image too bright or too dark.
- 16:15SPEAKER_00: So if you're um you're just finding your images and not everything's coming out wrong, just put in some exposure compensation and that should bring it back in again.
- 16:26SPEAKER_00: Uh, you're photographing predominantly white or dark scenes, so in those situations, if you're using uh a metering system that's evaluating the whole of the frame, then that will throw it off.
- 16:40SPEAKER_00: So exposure compensation is one way of correcting that.
- 16:44SPEAKER_00: Or you like the settings that the camera's choosing, but you don't like the resulting brightness, or it might be too bright or too dark, or it might be you just want to deliberately be a bit more creative and um force the exposure one way or the other and see what sort of result you get.
- 17:01SPEAKER_00: It would definitely influence the mood of the image.
- 17:03SPEAKER_00: So um I'd certainly recommend that as something to um experiment with.
- 17:10SPEAKER_00: So when isn't exposure compensation the best solution?
- 17:17SPEAKER_00: Now um I'm not here to tell you that everything can be fixed with exposure compensation, it is an option that you have when the exposure is not correct, but there are or there is at least one other thing you can look at, and that's the metering system that you are using.
- 17:41SPEAKER_00: So generally, what you will have or the default is something like um evaluative meet metering.
- 17:49SPEAKER_00: So most cameras will have three or four metering modes.
- 17:53SPEAKER_00: So, what I mean by that is it will decide you actually choose with that mode how much of what's in the frame is used to um work out what the correct exposure should be.
- 18:05SPEAKER_00: So the default tends to be evaluative or matrix metering that uses most of what you can see in the viewfinder or on the screen at the back, so it uses most of the frame.
- 18:18SPEAKER_00: So this is the kind of metering that's probably more likely to be thrown off because you're evaluating in most cases pretty much everything that's within the frame.
- 18:28SPEAKER_00: I think in Canons it's about 90% of what you can see, to that uh you know, the majority of the frame.
- 18:34SPEAKER_00: When you go to something like center-weighted metering, which is the next one, you're metering to an area in the middle of the viewfinder with the weighting on what's absolutely dead center, and it will ignore the outer edge of the frame.
- 18:50SPEAKER_00: So this is a more useful metering system where you might have a big variation between your subject and how bright or dark that is and the background.
- 19:02SPEAKER_00: And then the final option is spot metering, where you're just taking um uh a very small area, uh generally just a few percent in the center of the viewfinder, and um the camera is only metering on that.
- 19:16SPEAKER_00: And the reason why that one's useful is that's generally when you're setting the metering, uh, you that's generally where you want to pop your subject.
- 19:23SPEAKER_00: So you're now metering directly off your subject.
- 19:26SPEAKER_00: So that's more likely to give you fairly accurate metering, a fairly accurate exposure uh without needing compensation.
- 19:35SPEAKER_00: But compensation is there as a way of just correcting it if it's if it's got it wrong.
- 19:40SPEAKER_00: Um, another thing to do is just manual exposure, of course.
- 19:44SPEAKER_00: Uh, you don't need to um have everything automated.
- 19:47SPEAKER_00: So if you've got consistent lighting, or you can control the lighting if you're in a studio, um, or you could be photographing a series of images in the same light, or you don't want the camera changing exposure because it depends on what you're shooting, you can get a sequence of images, but the exposure is slightly different on each one.
- 20:05SPEAKER_00: So if you print them as a sequence, you you might have to just tweak the exposure on each one, otherwise, they might be slightly different and it will look a little bit odd.
- 20:16SPEAKER_00: Or you could be working in uh a situation where you've got very difficult um contrast.
- 20:22SPEAKER_00: So, I guess to summarize this, the kind of things to think about, first of all, I generally use automation, I don't often shoot in manual, and I do that for a very simple reason that a lot of what I'm photographing happens fairly quickly, and so for example, wild breaching or something happening with um wildlife in Africa, say that will all happen very uh quickly, so you don't have time to keep changing everything.
- 20:57SPEAKER_00: So it makes sense to let the camera do some of the heavy lifting for you, and that's why I use modes, and that's why I generally use so I'm I'm generally more interested in depth of field, or if um shutter speed is there, I'll generally um just push the ISO up a little bit to make sure the um shutter speed I'm getting is in the range I want for the depth of field that I want to uh shoot.
- 21:19SPEAKER_00: So automation is the place to start.
- 21:21SPEAKER_00: If things are not correct, then look at exposure compensation as a way of tweaking things.
- 21:27SPEAKER_00: So exposure compensation is a way of correcting uh the automated exposure level, and then the other option is manual exp manual exposure, so you'd start doing everything manually.
- 21:39SPEAKER_00: Uh again, though that's really only practical if things are not going to be changing too much.
- 21:43SPEAKER_00: So it's great for studio work, for example.
- 21:47SPEAKER_00: Now, um the other tool that you have on the camera is the histogram.
- 21:52SPEAKER_00: So, what exposure compensation does?
- 21:55SPEAKER_00: It changes the exposure.
- 21:57SPEAKER_00: And if you look at the histogram, which digital cameras have on the back now, um, and you you may have seen it, and you could you can use the histogram live, or you can look at the histogram when you're looking at An image when you add exposure compensation, the histogram moves towards the right, and it's that's um exposed to the right is essentially just one of one of the methods you can use to get um I'm I'm trying to avoid saying a correct exposure because what's correct is what you want it to be, it gives you the result you want.
- 22:29SPEAKER_00: The correct exposure for you might be something that's quite dark, for example.
- 22:33SPEAKER_00: But the histogram gives you an idea of first of all dynamic range you've got, so the difference between the the brightest area and the darkest area.
- 22:43SPEAKER_00: So if the full histogram is used full left to right, then you've got a wide dynamic range, but if only a small part is there, then you're you're reducing the dynamic range.
- 22:52SPEAKER_00: And um when you add exposure compensation, the histogram moves to the right, so that's where the the brighter part is, darkness to the left.
- 23:01SPEAKER_00: The things to look for are just highlights clipping, so hitting the uh the top of the histogram there.
- 23:08SPEAKER_00: If you want to reduce the exposure, the histogram moves towards the left.
- 23:12SPEAKER_00: And the thing to be aware of there though is you just want to watch for important shadows and details disappearing.
- 23:22SPEAKER_00: Because if you've got very fine details, so let's say feathers on a bird, if you underexpose too much, you'll lose that detail.
- 23:31SPEAKER_00: So if you're photographing uh, let's say a white bird or an animal, you might have very little tolerance for overexposure because what happens is that once those feathers or fur highlights have completely blown out, they're overexposed, there actually isn't any detail left to um recover because you've you've the histograms clipped at the top, you've overexposed that particular part of the animal, and you might want that detail.
- 24:00SPEAKER_00: Uh, so you do need to just be aware of that and and be very conscious of if you're happy for some areas to be blown out, to be too bright, or if you're happy to lose some detail because things are too dark.
- 24:12SPEAKER_00: So it's all about finding that balance, and and this is why exposure compensation can be quite useful in just varying what the camera is um giving you as a um correct exposure for that particular image.
- 24:27SPEAKER_00: So if you want to try this out, something you can do is just uh find a subject where you have contrasting tones or um uh a subject where it might be the someone standing in front of a window, for example, and just take three photographs, one with zero exposure compensation, so your your reference photograph, then one with exposure set to minus one, so you've underexposed it by stop, and then another photograph with the exposure compensation set to plus one, so you've overexposed it by a stop, and then just have a look at them.
- 25:03SPEAKER_00: And the the sort of questions you're asking are which looks best, which looks most natural, which one has the best highlight detail, and what's the what does the histogram show?
- 25:14SPEAKER_00: So you can look at the histograms after you've taken them as well, and then just try it with the predominantly white subject and a predominantly dark subject.
- 25:23SPEAKER_00: And and what this does is it gives you um much more of a feel for what's achievable with exposure compensation on your camera with the setup that you have.
- 25:35SPEAKER_00: And once you've got that feel, and if you practice with this a little bit, you can just look at a result, and if you're not happy with it, you immediately know what you've got to do.
- 25:44SPEAKER_00: You know that you need to do minus two-thirds exposure compensation, for example.
- 25:49SPEAKER_00: So I just want to um finish with this with just three things to remember if you're not familiar with this.
- 25:55SPEAKER_00: So if you do a positive exposure compensation, you're making the image brighter, you're overexposing it, um, at least versus what the camera thinks.
- 26:04SPEAKER_00: If you do a minus, a negative number, it makes it darker, you're underexposing it.
- 26:10SPEAKER_00: And the time to use exposure compensation is when you like what the camera is controlling.
- 26:17SPEAKER_00: So, for example, aperture priority or shutter speed priority, but you don't like the exposure it's producing.
- 26:24SPEAKER_00: So the thing to remember is your camera is very good at calculating exposure.
- 26:28SPEAKER_00: It's one of the really great things about modern cameras, but it doesn't know what you're trying to create.
- 26:33SPEAKER_00: That's obviously down to you.
- 26:35SPEAKER_00: So, exposure compensation is your way of really just adding another layer of creative control over what the camera's giving you so that you're fine-tuning uh the result that you're producing.
- 26:51SPEAKER_00: So, I hope you're um I hope that made some sense.
- 26:54SPEAKER_00: Hopefully, um, if you didn't know much about exposure compensation, it's a bit clearer now.
- 26:58SPEAKER_00: Uh, I definitely recommend that you go off and give it a try because this you know, this stuff's all very theoretical, but photography isn't a theoretical activity, you've got to be hands on, and the only way to really uh understand it is to just go out and try it and um look at the difference with different subjects and then just practice with it until it becomes second nature.
- 27:18SPEAKER_00: So that's it from me.
- 27:20SPEAKER_00: I'll speak to you again uh next week.
- 27:21SPEAKER_00: The next podcast is out on Friday.
- 27:24SPEAKER_00: Um, hope you have a good week.
- 27:25SPEAKER_00: I'll speak to you then.
- 27:26SPEAKER_00: Bye for now.