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Lesson 15 from: FAST CLASS: Fundamentals of Photography

John Greengo

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Lesson Info

15. Histogram

Next Lesson: Dynamic Range


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Photographic Characteristics


Camera Types


Shutter System


Shutter Speed Basics


Camera Settings Overview


Camera Settings - Details


Sensor Size: Basics


Focal Length


Lesson Info


all right. Next up is the hissed. A graham hissed A gram is very important for judging and making sure that you have got the right exposure. So when you play back, an image after you've taken it, which you want to look for, is an info, information, button info or a display button on your camera. Or perhaps something else depends on the camera you have that allows you to see this little graph. This is a graph of the tonal distribution. It's gonna tell you if your picture is too light or too dark. All right, So what this graph is is it's showing you all the pixel. So we have white pixels, we have black pixels, and we have all these different shades of gray. And for the moment, we're going to forget about color. All right, so we have a picture that's composed of a lot of different pixels. And in the history, Graham, what we're gonna do is we're gonna organize all these pixels. So in the very left column are black pixels and then ones that air really near black and then over to the right h...

and side, where we put a white pixel And so now we have a graph where we can see. Okay, we got a whole bunch of middle grey pixels and a few dark ones and a few light ones, and it's very, very easy to see if you got the right exposure just by the shape of the hissed a gram. So a hist a gram might look a little something like this. So this vertical height is measuring the number of pixels at anyone brightness level, and then it's broken up from left to right, going from darks shadows, mid tones, toe highlights, and you can easily see if there's a lot of pixels in one particular group. And so this has a lot of pixels in the mid tones, which is where a lot of normal pictures are going to be now. One thing you want to keep an eye on is the left most column, because those air pure black pixels, which means that you have got essentially no light in to those pixels. And so if there's a lot of them that are stacked up really high in that left hand column, you've got a really dark photo. I'm not saying it's bad. You've got a really dark photo, and you may need to take a look and judge if that's appropriate for what you're shooting. Same thing goes with the right side of the graph is those are the white pixels If you have a lot of white pixels, those were going to be blown out pixels without any color without any detailed information. And that's probably not a good thing. In most photographs. It really is something that you have to look at on an individual basis, and so we'll be looking at a bunch of different photos in here. Many cameras will have two different options on graphs. You can either choose a brightness one, which is just all the pixels combined together, which is a good way of judging the overall brightness. And then there's RGB, hissed a grams, which separated out into red, green and blue pixels, so you know how bright any one particular channel is. I find the RTB hissed a gram a little bit easier to read. I like the colors, and it can tell you if you're getting a really bright area in one of the colors where you may get some clipping on that Now this is really handy to have on a digital camera, especially a non muralist style, because when you look at the back of the camera under bright light or even just normal outdoor light, it's hard to judge. Is that the right exposure or not? Because it's being influenced by the light hitting the LCD on the screen? If you have a mirror list camera, you are it a little bit of an advantage because you can hold the E V F up to your eyes, block out all that extra light and get a better view of what that final image is gonna look like. But the hissed a gram is, I think it's It's like the lie detector test for pictures. Did you or did you not get the right exposure? And this will let you know that you got the right exposure. Generally, what you're worried about is a big mound of information over to the right hand side for over exposure and a big mound over to the left hand side for under exposure. But you should not just assume things with hissed a grams. Every photograph is gonna have a different looking hissed, a gram. And so I encourage you to play back your images. Look at your history, grams, and start learning about what's going on in those photographs. And so we're gonna have an impromptu quiz here on this one. And so what team are we next up with A or B do? Does anyone recall who the last question was with? And so for Team A, the question is, is what's this? Hissed a gram gonna look like you have any sort of ideas on what this hissed a Graham is gonna look like. Just give me a general idea. What, you think it looks like it's gonna be the big spike on the right hand side, Big spike on the right hand side. And we indeed have that. So that is That's worth a point, I think. And so there is a big spike in the right hand side because we're photographing Snow Snow. It's light. And in this case, we do have a big spike up here. And just in case you're wondering this other little mound of information in here, would you think that IHS Anybody want to just call it out the sky? Yeah, that's the sky And you also see the blue channels a little bit brighter there, so you can see that actually sticking out there. Okay, we're gonna go over to Team B, and we're gonna do the reverse. Here's the hissed a gram. You tell me what we're photographing. Just tell me what you think the photograph looks like. So this is either under exposed or just very dark, like rights guy. Okay, So is it a very dark photograph? It's a dark photograph. It's from nighttime. So they get a point to. That was kind of a free bonus point for everybody There didn't do anybody did it. Uh, you want to be able to look at photographs? Guess what the hissed a Graham is gonna look like. Look, a hist a gram. And guess what the photograph is like. All right, So what? I'm photographing this and I'm looking at the photo, and I'm thinking, Is this the right exposure or not? I can't tell. I would like more information. Let's look at the history, Graham. Oh, we've got a lot of information way over on the right hand side. Let's try darkening this photo up. And so now we can see a lot more color information in the sky, and so this is just a really useful tool for knowing if you got the right exposure. All right, One of the things I just told you moments ago was be aware of spikes on the far right hand side. In this case, we do have a definite spike on the far right hand side, but in this case, I don't care about the spike on the right hand side because it's a cloudy day. It's one of those overcast days that has no texture in the sky at all, and it's the subject in the middle of the frame. That's most important now. Some of your cameras will have blink, ease. And these are things that you can turn on and off that show you the highlight clipping of pixels that have become overexposed. And this could be very helpful. For instance, for a wedding photographer. If the bride's dress is completely blinking, you have no detail in it. She's probably going to be mad. You better change your exposure so that you can see some detail in those highlight areas now. Ah, word for those more advanced users this is a hist a gram that you see in your camera. It's of the J Peg preview of your image. It's not the actual raw image, so it's quite possible you could get these blinky highlights turning on telling you, Oh, no, the world's gonna end, but in reality, on your raw image, you actually do have all that information. And so it's kind of a precautionary warning that comes on a little bit sooner than it actually needs to. Come on. If you are shooting and raw. If you are shooting in JPEG, it comes on right about when you need it. So when you're judging the exposure of a picture that you've just taken, there's a number of things that you can look at. You can look at the back of the camera. You can look at the history, Graham. You can look at the light meter. You look at the scene with your own eyes and you're like a private detective who's trying to figure out what's going on in this mystery. But you have different pieces of evidence, and so you need to be looking at all these pieces of evidence to see if they match up because I can't tell you this is a bad hissed a gram because it might be appropriate for a certain type of photograph. This is a tricky situation. I have a very dark subject in a very light background, and I am really stretching the range that my camera can handle because there's important information over on the left and some pretty important information over on the right. Now, when it comes to the hissed, a gram and exposure, I can move left and I could move right. But I can't stretch things out or squeeze things. Okay, that's not possible in. So we can change your exposure and make it brighter or darker. But we can't do both at the same time. And so that gets to be very tricky when we are in high dynamic situations where we have very bright lights, highlights with clouds and waves, and then we have very dark shadows. And so we have dark areas and we have light areas. And if you're asking But John, how do I make a better photo? Come back at a different time when the light is better? This is why photographing in the middle of the day could be very, very difficult. And so be aware that if you're getting extremes, there's only so much you can do with your camera. And there are limitations and there's always gonna be. I mean, the cameras have been getting better and better, and I'll talk about some of the best cameras when it comes to dynamic range here. But there are just limitations of brightness levels really bright and really dark at the same time is very challenging for capers. Now, as many of you know, I'm a big fan of visuals. I love visuals, and I like colors, like to be able to see things. I think this is a really fun looking hissed a gram, and it's an equally fund photograph that goes with it. So compare your hissed a grams. Look at your photographs. I think this is kind of an unusual hissed a gram here. Does anyone know what's going on here? Anyone want a throw out? A guess as to what's going on in this photograph. There's something, uh, there was what was that? Ah, clown video shit. And so one of the things is that you'll see these color channels really spiking when there is a noticeable color. What color is really noticeable in this photograph? Red and green combined to form yellow. That was an all ha moment right there. And you know what I was When I make this class, I go through all of my photographs, and I'm looking for examples of this and that. And so I was working on this section. I'm like, OK, I need some good photos that show an interesting hissed a gram. And so I had this weird photo oven led who? But I'm like, Okay, this is gonna be a cool hissed a gram, and I pull it up and I'm like, it's not really that interesting. And so it does not necessary correlated between the photo and the hissed. A gram. I think this is a pretty interesting history, ma'am. Right here. There's something weird going on here, and I'm gonna ask you because like, I would never guess this myself. But here's what's going on is that there's a lot of different colors and there's just slightly different brightness is of that one color according to where it ISS. And so I think it's intriguing because you start learning about your photographs when you study the history. Grams. I've been using this one in my class for many years. This is, I think, what I think is traditionally thought of as a terrible looking hissed, A gram spikes on both ends. That's like the worst case scenario in a photograph. So you must have a terrible photograph. Not necessarily. Things start to make sense when you see both ends of the hissed, a gram and the photograph, and so hopefully that makes a lot more sense for you now.

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