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Histogram Pop Quiz and Q&A

So now it is time for your official pop quiz on histograms. So, let's see how we're gonna do this. We've got just a few questions in here and so, I'm gonna show you a photograph and I have taken this photograph at a number of exposures and I want you to pick out what you think is the best histogram for this. And so, we got three. So, we got three people in the front row. So, let's start on the right. You'll be the lucky one. So, here is the photograph. And now, you need to kind of assess is this bright? Is this dark? Now, before I even show you the histograms, what do you think about this photo as far as brightness and darkness? Well, it's a little bit ... Well, the colors are a little bit on the darker side but it's not a dark one so it probably wouldn't be on any of the blacks. And there's not really much of just straight white so it should stay around the middle. Okay. So here are the three potential histograms that it might be. And so, each of these would be the result of chang...

ing your shutter speed or aperture and capturing this camera at different places. And so, if you've got this and you couldn't tell by looking at the photo, you had to judge which one of these histograms would be the correct histogram for this scene, which one would you choose? I'd probably choose B because a little bit more of the grayer, middle ground tone. The correct answer is B. Give her a round of applause. Right on. Nice job. Very good. Okay. So let's just say you had chosen A. Here is what the A photograph would look like. It'd be much brighter because that histogram is more over to the right hand side. If you had chosen C, it would look this. A little bit darker than average. Now, the fact of the matter is that exposure gives you a little bit of play latitude. And if you had done this, you could still fix it and make it look right in post. But we're trying to do the best practices here. We're trying to get is as right in the camera as possible. Alright, let's look at our next photograph. Alright, then there it is at B. Alright, next photograph. We're down in Florida here. So, what do you think of lightness and darkness in what you're seeing in this photograph? I think everything is very dark except for his eyes, in between the eyes, and up towards the back of his tail. That's where your light's going to come in. So, which one of those histograms to do you think best represents this subject? I'm gonna say A because you have just a little bit further light (mumbles). So which one of these histograms is gonna give you the brightest photograph? Okay. A is gonna give you the brightest. So it would be C then. So you're changing your ... I am. I'm changing... Did I give you permission to change? No, but I'm gonna do it anyway. Okay, well, that's good enough for me. And the correct answer is C so round of applause here. Nice job. (audience applause) Okay, so let's just say that you had chosen B. That's not too bad there. I mean, we can make that work. It's supposed to be really dark because this is, you know, really, like, black water and this really dark creature in here. If we had chosen A, it would be much, much brighter than it's supposed to be. And that's a mistake here and so, in this case, it's a fairly dark subject. We want a fairly dark histogram. And normally, I would be concerned about a histogram that far off to the left hand side. That would normally be a concern but when I know the subject, it makes sense. So you have to be able to draw a conclusion with a couple of pieces of information. Alright, let's do our third and final photograph, here. Alright, so what do you see in the photograph? What do you notice about lightness and darkness? There's a lot of light. A lot of white. And so, which histogram? You've got a pop of color in the back there. So, I'm gonna go with, I'm gonna go with A. Going with A. Alright, and let's see. Folks, we are three for three here. Nice job on the front row. (audience applause) Nice job. So yes. This is whitewash paint. We have white everywhere except this small area which is what, maybe what, 15% of the whole photograph? And so, predominately white. If we had shot this at the middle exposure it's gonna be kinda this muddy, dirty white. It's not quite the right color. And if we had shot it at C, it would have been clearly too dark. But the camera kinda inherently wants to shoot it at B and this is where you have to be smart and go wait a minute, this subject is brighter than average. We need to get that histogram off to the right hand side. And so, nice job on that histogram. Alright, so here's one more for you guys at home. Here are three photos, and this is one you can just play at home. I've got one, two, three photos and I have three histograms. See if you can line up the correct letters with which histogram goes with which photo. I'll give you a moment and we'll see if one of you wants to give us the right code. So these photos, you just need to look at the photos and have an overall assessment. Is this brighter or darker than average? What things are bright? And it's not really what the subject is, it's more how many pixels does it take up that's either bright or dark. How quickly does it go from light to dark? Okay. So there's a three letter code that I'm looking for. And people on the internet can start typing in their three letter codes. ABC. CBA. Back and forth like that. So, somebody in the back row, would they like to offer their code on how to decipher this? CAB You've got CAB, right? Okay, so let's see how we're doing. And that looks very good there. Would you mind telling folks how you figured some of those things out? What did you look for? Well, I looked for the extremes. So, so much white in three and I can see the histogram is pushed all the way to the right. Two is very dark and the histogram's, the majority of it's to the left. And then the not hard but the hardest of the three would probably be just number one. But I could see of those three histograms, C made most sense. Okay. And so yeah, obviously the all white area here makes the most sense with a big old spike on the right hand side. These two can be more difficult to choose between the two, but you do have almost, what is this, that's like a quarter to third of the frame, that's a ... Two-thirds of this picture is really dark and so you're gonna see that over here. And it does get bright but it very quickly goes to dark which is kinda that steeper curve here. Most of this is more even exposure. And so that explains most of this area in the middle tone. But as you get deeper and deeper into the chains, it does get darker and darker, so there is a fair bit of dark. So, good job on that. Very good. So it looks like these folks have really learned their histograms quite well. So nice job, folks. This might be a good time, I don't have a Q and A slide, but just catch up on any sorta questions we may have at this point. Is there anything we need to check on? We have something in class. So I had a question, that, you know, you showed us the the highlight peaking. Yeah So, I don't know if there's something that shows, I guess, the darkness peaking in the camera. So I don't know if that's an option. No, there isn't but there very well could be on future cameras. That makes perfect sense. Right. Generally highlights are the ones that we tend to have the most problems with. It's quite natural that there are some areas of darkness. For instance, right now, if you take this camera that's on right now. If we look at this area here, there's nothing that's perfectly white. Even the screen has a little bit of texture. But maybe down here, there's some really dark shadows that you're just not gonna see any information on. And so, if that was your camera, there would be a bunch of black blinking down there. And that's something that we see quite common. There's things that are just kinda lost in the shadows. That's much more common. And so, that's probably why it's not an option on the cameras. Got it. Thank you. John, a lot of people were playing at home online. So, it's always great to see that participation, as well as some light bulbs going off. Can you talk a little bit, there's several questions about shooting to the right and shooting to the left. And when you would that, or what does that actually mean when you say that? Okay. So there is a philosophy that it is better to capture your image a little bit brighter and then darken it up later, afterwards. And you can do that and it can be beneficial in some situations. For the most part, I think it's best practice just to try to get there right exposure in the camera. However, if you want to experiment with it, you can overexpose by a stop, but the key thing there is you don't want to overexpose any pixels at all. So you can only do this in situations where, as we like to say, you have a lot of headroom. You're not gonna be bumping up against the right hand side. So if you're shooting something that's kind of middle tone gray and darker, you could record it a little bit brighter than average and maybe get a little bit cleaner signal and then darken it up later. It requires a little bit more work and the resulting difference is very small but theoretically they are correct that it could help out and make it beneficial in some areas. One more quick question. When you're evaluating an image that is shot in raw or shot in JPEG, is the histogram gonna be the same for both of those file types? They will be because the raw images are converted to JPEG on the back of your camera. So one of the things to be aware of is that when you're looking at the histogram you're looking at it for the JPEG version and the raw image will actually give you a little bit more. So if you a little tiny spike on the right and a little spike on the left, I wouldn't worry too much if you're shooting raw because there's a good chance that you're gonna be able to utilize that information as that histogram is not 100% correct. And that's something else I would like to see changed on cameras. I would like to see the actual, true histogram, for the raw image. And right now, it's JPEG on all the cameras that I know of. Good to know, John. What about, this is from Isogen. Does the histogram change if you select Adobe RGB versus SRGB in a color profile? I don't believe that you'll see any difference between those two settings. Great, thank you.