Lessons

Lesson Info

Knowing Your Limits: Histograms in PS

Sometimes clients give me images and either I don't feel like going into camera where I'm already done with camera and I need to do further changes when I'm in photo shop, so let's, take a look at how we can have some of the same ideas apply when we're in photo shop here's an image that's had some adjustments applied if I hide my adjustments, this is what was done in camera, and then I apply my adjustments it's just dark ing around the edges here. If you want to see what the original original looked like, I will double click on the bottom layer because it's, a smart object that contains the raw file and I can show you camera defaults. That was my original picture, so I did most of the change in camera, then it ended up in photo shop and let's see how we could get some of the same features here in photo shop. So first off, if you make adjustments with levels or curves, they both will offer you a history graham. But that history ram is thinking about like the overall brightness of your i...

mage, it doesn't show it to you in color, like it does in camera, where you can tell if you're getting saturation clipping versus going pure black and you're white. So if you'd like to be able to get a color history ma'am, you need to go to the window menu and in there you're going to find a choice called hissed a gram when you bring that open this shows up I don't know if I'm on default settings right now or not because I don't remember what the defaults look like but let's take a look at the options we have just in case yours doesn't look like mine there are two different sizes to this system graham and you can change between them by going to the side menu on the panel and switching between compact view and expanded view when you get into expanded view you have more choices so I go to expanded and you can see I have a little pop up menu if I click there I could see the history ram like I see it in levels levels are curves will give you one that looks like that or I can see the individual channels red, green and blue I can see city which thinks on ly about brightness ignores color or if I choose colors it's going to show me history gram that's similar to the one that we saw when we were in camera where if you see a colored spike on the end it means saturation clipping and if it changes from color to this this gray it is instead solid black or solid white after you've chosen that choice, you can switch back to the compact version of this if you would like or if you prefer the big one, go ahead and have it if you have a client over, you want to look overly sophisticated instead go to the side there's a choice called all channels view turn that sucker on and you can also show the individual channels and color if you leave that on the screen whenever you're working and act like you're looking at it when clients are there they never use it, so they're going to think you're doing more than unusual, but in general I usually have the colored version over here and find I don't necessarily need to look at the individuals but it can tell me am I losing detail in green blue and, um read by inspecting the am bitten individual ones that's up to you if you want to show the channel's uh we're not I'm going to stay here and expanded view and I'm gonna have it set the colors then another thing is you're gonna find a little warning symbol show up you see this little guy right here and what that means is that this history ram is not precisely accurate it's going to try to interactively change the history ram as you adjust your picture and in order to do that it takes some processing power and so it ends up working in a lower resolution version of your picture when it creates the history graham which means it's not precisely accurate if you wanted to be completely accurate, you can either click on this symbol or this one uh and that's going to make it recalculate the history ram from the full resolution image and you'll find it switching back or that little wind that little warning shows quite frequently as you make adjustments like right now if I make a selection so it only thinks about that area and I go back to thinking about the whole image it will reset itself the number you see down here that says cash level tells you how much smaller the version of the picture it's using uh what is calculating the history ram if it was a cash level of one, it means I think full size image cash level of two I think it's half size three might be a quarter sized for would be beneath size. I could be off on those numbers, but it's something like that. The main thing is the higher that number is the more this is an approximation so I can leave this open when I'm adjusting my picture the only problem is with default settings this appears is one of these little pop up panels and if I go in and make an adjustment like levels that thing's going to go away because this is also usually by default in a little pop up panel. So what I often do is I go to the history graham and I dragged its name over here into the area where you have color and swatches, because usually I'm either using the history graham or I'm using color, or I'm using swatches, but it's rare that I need to use more than one other time, and therefore I can have it there visible all the time, and then when I come in and do something like levels, curves or human saturation, I can still be visible. Then, when you're adjusting your image, just watched the ends of the history, if you see a colored spike saturation clippings going on, if you see a solid spike that's more of this great town that's in here, you have solid black or solid white, and if you want to see where it's happening within your image, what you need to do is go to either levels or curves, and you see these outers sliders, the one that is full of black or white, you could hold on the option key when you click on it, and it'll show you the same general view we had when we were on camera, so I can see that that area is forced to solid black in one area and we have a little bit of saturation clipping where you see those those colors that are in there and so you just have to decide is it more important to have detail in those areas where you see the color showing up uh or is it more important to keep them colorful if it's more important to see detail loader lower your saturation a bit until you don't see that anymore, but I wanted this area to be solid blacks he wouldn't be distracted by any detail that was in it so that's what we can do and either levels or curves we have these little sliders and you could hold on option when you click on him. There is another choice, though, and that is if you go to the upper right corner of levels or curves there's little side menu in one choice on the side menu is called show clipping for black or white points and what that means is when that's turned off in order to see that uh preview, I have to hold on the option key in click on this slider or the other. If you go to the side menu though and turn this on, then I don't have to hold on the option key it's just any time I grabbed this slider with no keys held down it all, I'd automatically get that for you and if I grabbed the opposite one bringing in let's say it automatically get that for you it's up to you what you prefer but just to show you the same thing is in curbs go here to curves see the two sliders at the bottom hold on the option key when you click on one you get the same view in on the side menu same choice so you'd have it up uh automatically when you grab this all right so that's how we could get the same view that we hadn't camera on when your photo shop and just know again that uh it's only guide nobody else is going to see your history graham so that uh you don't have to have the history ram perfect instead use that as a guide to say do I want inspect my shadows or highlights or the most colorful parts of my image to see if it's worth getting that extra detail back so it's up to you chuckled a minute ago because I glanced down at my notes and of course somebody on the side wrote we heart karen on I usually have a white board over near a clock over here that tells me what time to stop for the next break and it says sideways karen rocks I don't know who's sneaking in here I doubt it's karen but somebody's messing with true nonetheless so anyway that should give you an idea of either both saturation clipping and all three channels being clipped, just something that use useful to look at there's one of the thing that you might want to consider when looking at a history. Graham, you're mainly going to see this when you're in photo shop and you're making extreme adjustments, and that is here, I'll create a brand new document, and I'm just going to put something simple in this document. I'll put a grady in't from black to white. Sometimes when you work on an image, you're going to end up doing some extreme adjustments in doing those extreme adjustments, you might end up introducing what's called postal ization into your image. If you have something like a blue sky that goes over the full width of all really wide panorama in the difference in the sky is not all that great going across that wide area. If you end up making an adjustment, you might start seeing some stair stepping just or some people call it banding in your image, and I just want to show you how that would show up in the history ram, I'm going to do that by just taking this simple document that contains a grady in from black to white, and I'm going to reduce the number of shades that air in it, I'll do that by choosing posterized. And this tells me just how many shades so I wanted my image total in this case at least for now look what happens over here in the hissed a gram panel there's only four shades in my entire picture so if you look at the history and there's actually just four lines in the history ram one, two, three and four as I bring up the number of shades were going to seymour and more lines in the history graham you just watched the picture and see when you think it looks smooth when you can no longer tell that it's got that stair stepping or banding innit don't bring it up keep going! I can still see the banding now on the video feed your video feed is compressed and so it's hard to see if you're really seen exactly what I have here so it I'll let you know when I no longer see the banning he and it might be slightly different on the video feed though so I can still see the banning what I want you to do is keep an eye on the history graham and look at how wide the gaps are. What we want to find out is how um why do the does the gap need to be before we start noticing banding camera when am I gonna stop noticing I could still see it pretty skinny somewhere in here I'm going to stop noticing all that much it's looking relatively smooth but if you notice in the history of the gaps in between those lines are actually not all that great they're pretty small and so what that means is if you're a john senior picture and because of your adjustment the history ram starts getting gaps in it in the gaps or at least this big then if it goes any bigger than this any wider of gaps it might be something you could visibly notice in your picture and so if you're ever doing adjustment whenever you're done just glance of history ram and look for gaps but when I talk about gaps I mean gaps to go all the way to the bottom do you see the these gaps? They go all the way down to the very base that's here if the gap is only up here in the upper portion it's not something to be as worried about its when it actually goes all the way down here and starts touching the bottom and it's like two pixels wide I'd say all that means is if you see that inspect any area that would usually have a smooth transition like a blue sky in see if you start seeing banding where it looks like it's stair stepped instead of a smooth transition and if it is visibly that way what you will need to do with either back off on whatever adjustment caused it or to compensate for it usually you can end up adding noise to your picture if you add noise it breaks up the easy to see ah bands that are in your picture and makes the edges less kind of distinct and straight makes him harder for your eye to pick up on so that's the other thing to look at when you're looking at a history graham are you starting to get some gaps in it which might indicate that what used to be smooth now has distinct steps in it where you can visibly see him doesn't mean for certain that you're going to see them it just means you need to inspect the image closer than usual alright see might we love karen sheets here see if anybody else wrote stuff on the other sheets no they only been at the top messing with me all right then if you're going to convert your image to see him why came out you need to be careful because when you convert to seem why came out the scene white cake color space is something that can't reproduce his wide of a range of colors as you can have in rgb mode and so when you convert to see him why I came out you might find that certain colors shift on you so I want to show you how can you preview which colors might shift and where in your image you might want inspect it just in case you want to adjust it to find tune what's gonna happen when you go to see him why came out so to do this first we're going to go up to the view menu and in the view menu is a choice called proof set up in order to get photoshopped to simulate what things are gonna look like when you convert to see him why I came out you need to have this set toe working see m y k what working seeing why came out me mode means is we're going to simulate whatever settings air usually used when you choose this menu choice justly now you consent photo shop up for various kinds of printing and printing press before you convert to seem like a mode but going to the edit menu and at the bottom of the edit menu is a choice called color settings and the way you set up if you're converting the scene why k mode let's say for the newspaper versus a magazine versus high quality uh brochure printing is in color study and there's only one setting to change its right here called c m y k this setting right here tells it what type of printing you're doing and you can either guess if you're not certain how it's going to be printed or you could ask a printing company you know what kind of setting they should use here ah when you convert but this setting needs to be chosen before you convert the image to see him. Why I came out because it's used in the process of converting the scene, why can't so when I come over here and set this thing called proof set up toe working see m y k, that means simulate what this will look like when I converted to see him. Why k mode using the settings we currently have set now if I go to the view menu there's a choice, two of them once called proof colors and the other is called gamete warning. When I choose proof colors, it means simulate scene. Why came out? Just show me exactly what the picture will look like if I were to convert it to seem why came out so when I choose prove colors, if I go back up to the menu, you find a check box next to it and you'll see there's a keyboard shortcut command. Why control why in windows so I could quickly toggle it on and off to see if there's any difference in the image and you see the red portions of the image changing well, the red portions and the image are the areas that are obvious that are changing, but there might have been other areas that were changing in a more subtle way. That you just might not have been aware that happened, so if you want photo shop to show you exactly where the image changed, you can also go to the view menu and choose gamut warning if I choose that it's going to put gray on top of the image wherever it changed and so I can see that there's some little smaller areas that I might not realized over in here and I didn't notice over here on this hat a little area shifting so gamut warning all it does is put gray on top of the image where of it needs to shift when it converts to see why k mode where as proof colors actually shows you the shift, so if I take command wide a toggle proof colors on and off, I can see that and if I look at the hat on the right side, I barely notice it changing I really have to stare at it to see it change it all so I don't think it's a concern but it's that red nose that might be you can tell if proof colors has turned on without having to go to the menu to see if it's on if you look at the title of your picture up here, it tells me the name of my file, what magnification on viewing it out, the mode that it's in and how many bits that isthe then if it says scene, why kate after that? So it's saying both rgb end seemed like a? Well, if you see this part in the end, that means that prove colors is turned on. So if I type command, why you see that going away up where the title is so that's a visual indication. So if you know this is an image is going to be converted to see and why came out, what you might want to do is turn on proof colors before you start adjusting your picture, because there are a lot of colors, especially deep blues, that are very difficult to reproduce and saying, why k mode, but very easy to make an rgb. And so if you know you're going to end up in seeing why came out before you start adjusting the colors in your picture, you might want to turn on proof colors to get a preview of what I look like and seeing why came out in that way, you never are able to saturate the image so much in cia deep, deep blue show up. Instead, it shows you what it would shift to, and seeing white came out, uh, and therefore you never get enticed into using colors that aren't printable otherwise, ted command wide a toggle. Back and forth and decide, do you like to shift the color of this red portion to maybe it more oranges or more yellowish to get more into a printable range? Or is it okay to use to have that little shift that you're seeing but that's? One other area that I would consider when thinking about my limits? Because seeing white came owed cannot reproduce is wide of a range of colors as rgb. Also, if you ever clicking on your foreground color to choose a color to paint with or a color to use for text, uh, with that it's very easy also choose colors that are outside the printable range. And so if you're ever choosing a color and you're about to use it for texture painting, you know you're going to end up in scene, why came out? Then pay attention to this little symbol right here when you're in the color picker, if I choose let's, say deep blue that's going to show up what's gonna happen is inside the little square that's there it shows me the color that's closest to this one that it could make it seem like a moat. So it says, hey, this is the color you've chosen. This is as close as I can get in seeing white k and you might. This will click on that little square. Then, if you know you're going to end up and seeing white came out toe, actually, use that color. So you never created design that contains overly saturated colors that aren't reproducible in seeing like a mice will start what colors that are reproducible.