Removing Color Casts

 

Advanced Adobe® Photoshop® Techniques

 

Lesson Info

Removing Color Casts

so this segment we're going to talk about color and color correcting there's a new catchphrase out there that's been around mostly in the motion pictures he called color grading which is just another way to say adjusting the colors the way you want so there's consistency between images and things of that nature so I'm gonna show you a bunch of different techniques some of which are maur eyeballing and others are a little more numerically correct and ways where you can end up fixing things in the ways we want needless to say if we are the person holding the camera and we are shooting in raw and we have chosen what appears to be a relatively good white balance that's already a good start because we're already in the right frame of color space and in terms of shading and everything and also easier to change and rob I'm going to show you some different ways depending on what you have available to you so first of all let's just talk about if you wanted to just look at something visual on yo...

ur screen and say that looks like the colors little off to me how can I just that toe look a little better there are a couple of ways we can do it including ways that are very just um what's the word I'm looking for just eyeballing and it's not a technically perfect way to do it but if you just say you know this color looks a little off to me I want to adjust it and it's a jpeg file so I don't want to bother going into camera commands like levels and curves have a neutral gray eyedropper so I've added an adjustment layer because I want this to be on ability that aiken test and see and then I can look at something I say I think this area here looks kind of grayish maybe in here and then it makes an adjustment and if you're not quite sure about that one you khun try somewhere else and it will make adjustments along the way but that's just me doing it as a way that artistically I just want to say this is a color that I like but there's not a lot of technology behind it uh than me clicking and saying I think that's a good spot so that would be one possibility once you were I'm happy with it then you could apply that adjustment layer or just leave it there in case you ever wanna tweak it further one of the things that people have often wished for in photo shop was a white balance tool where you could just click and say click on something to adjust the white balance photo shop doesn't have it but now that in the last couple of versions we can use the camera filter it means even on a layer we can go in here and take advantage of the white balance tool right in aside camera raw and do it that way so that be another option to say I want to adjust it and of course then we had the added bonus where if we still want it tweak the color temperature or choose to try an auto setting I don't find that auto setting often does it for me I like to do it myself but least you can tweak it further say that's pretty close by like a little more towards this color temperature and when you click okay now in this case I chose this for the sake of argument not to make it a smart object but normally I would just in case I wantto apply that filter and see the white balance and then later on in a project I think well maybe that's not exactly what I wanted after all now the bottom layer of this because I chose to make two different copies of this actually is a camera smart object and say in this case I could just go directly to camera to adjust the white balance there this is the original raw files on this case you can see I am in fact getting all of the white balanced settings and oddly enough I find on a raw file when I choose auto white balance it often looks pretty good on a j peg but I pick auto white balance I'm often not completely satisfied so I think that's just because the white balance information the raw file just does a better job but as I mentioned earlier especially if you're in the kind of just looking at him and say I think I want to look this way you're not trying to technically balance it correctly you're just tryingto visually artistically changed color there's actually nothing wrong with single what do these other white balances look like even though they're the quote unquote wrong white balance you might end up finding something you like even this one tungsten that's too far but then I could also pull it back a bit and go that's not bad I kind of like that so there's actually nothing wrong with starting with any of the built in white balances with a raw file and then tweaking the results a little bit if you're just trying to say I think this looks better so that's one option we always have available to us the other one which is kind of interesting and this is an old school technique that I I wish I could remember where I first thought I think katrina heisman had might have been the first book that I saw this technique and was just helping figure out what kind of color tent if there's a color cast a cz we used to call it when people still do but mostly the printing business has been a color caste do it mean this kind of bluish greenish or whatever but trying to determine what that color waas was often a bit of a challenge so if we I'll see if I can do this as a smart up never actually tried before but let's see there's a blur function called average and what that does is it looks across the whole image and averaged out the pixels and it often tells you this is the color caste thatyou have you see the color that it's appearing is greenish what I want to do is to be able to say it out to take that away I need the opposite color invert that and then see if I can not work this way we'll find out in one second I've never actually tried this before let's see color yeah it didn't work that way okay so I'm not going to do it as smart as I thought I'd try it just in case because we'll be cool if I could but let's step backwards here so it was going to be easier for me if I do it as a separate layer like this this is one of the rare times you'll see me use the command called rast arising only because this is a temporary measure I'm still ultimately using the bottom smart objects of this top one we will now do that blur average and then I just press committed control I for invert and if I change the blend mode to color and then knock down the opacity and this is where the bit of guesswork comes in but you can see that's taken away that color cast because I've taken the opposite color and applied it with this blood mode called color so both of these air still kind of a way where you're looking at it saying that looks better to me and for many circumstances where you're preparing something for your own purposes for a website for facebook even if you're printing it this at least gets you mohr into the correct look that you want however we might want to still be able to do it a little more technically correct and I buy sat by that I mean with some feedback that photo shop gives me instead of just my eyeballs and I'm not going to deliberately here get into a a hole discussion of calibrated monitors all that kind of stuff because that certainly is a help but for many of these things if you're just trying to say I just wanted to look more like this kind of color these methods are good if you're faced with a document that has a color cast this is a jpeg so if I tried to do auto white balance I'm guessing it probably wouldn't work all that well just from my past experience of trying that so I'd like to try the method of clicking with one of those grey I droppers the problem is on this photo I'm not entirely sure where I should be clicking so I'm going to take advantage of a technique that I came up with many years ago that that I will say right up front it's not technically perfect but it's way better than guessing so ifyou're instead of you going I think that's a good spot with the eyedropper and clicking all over the place this will help you narrow it down and I preface it by that because I used to show this years ago in workshops and there'd be at least one engineer in the crowd would say well I don't know that the luminosity of that is really made get out I'm like okay so that's why I now say yes I understand but it given the alternative me just arbitrary trey really going I think I will click there this is better so very simple process and you could actually create an action for these first few steps if you really want to because it's always the first part is always the same we add a new layer and we fill that layer with fifty percent gray one of the blend modes that's available to us in photo shop is called difference and let me show you if you haven't seen different smoke before this is what it does if you have a copy of the layer that's exactly the same when you change the moe to difference going to compare the pixels and everywhere the same it will be black or a very very dark color in this case it will be black if I choose difference because there's literally no difference all I see is a jet black image not that you would do this I'm just trying to show you what difference mode does watch what happens soon as I take the move tool and shift the pixels even a bit then because they're not exactly the same position now I'm getting different shades so one thing's people use difference mode for is say you were trying to take the I don't know the head of some one on one photo and match it up with the body on a different version the photo this could help make sure that areas that were similar were lined up in our case the reason I'm showing you this is when I have this fifty percent grey layer if I change the blend mode to difference that suggests that anywhere where there's grey underneath it should be very very dark if not black so this is a start to help me narrow down any parts where it's very light colored I know that's not a good place for me to use but I want to narrow it down even a step further so I used an adjustment layer called threshold now threshold is a say this eh not an everyday typical use of adjustment layer because it takes away all color and all shades of gray and just makes things black or white which in many cases would be well bad but this case what it does if I move this all the way over to the left the first pixels that will appear when I start move this slider in will be the blackest parts of this and the blackest parts would mean the parts that are closest to fifty percent great because remember I took that fifty percent grey layer changed the difference mode this is helping me highlight which areas of the very first areas that appear should be the darkest part of the image now I usually like to go just a little bit further and give myself a couple of places to click on so I instead of me trying to remember where should I click if you use this tool called the color sampler tool which shares the same slot is the eyedropper tool you can actually mark a spot and say I'd like to try that one there and maybe this one over here and you could try I mean you could do multiple that he really wanted to and you could even push this a little further and see I'll pick a third one just for the sake of argument okay so once I've done that you could do one of two things either just throw these both away or if you think you might need to tweak it further temporarily hide both um in this case I'll just hide them both so you can see now if you look close you can see there are three little samplers there which are marked the three spots that I just saw it a little hard to see because they're color but it said there's a one two three four two three one two three so those are the three spots that I just marked now I take a these want to use frankly is just levels because again and take that same gray eyedropper instead of me guessing where should I click I'm going to try to a line that up and say well let's drive this one and see it's not bad I think I like that one better what's this one look like that's about the same so there's still a bit of an element of playing around guessing but the theory behind this is it just means that giving me a better idea of where it would be a spot that I would play considered me totally guessing in some photographs you can look like oh look at that there's a a great part of the pavement that I know that's a good grade but one certain areas like this where you just not sure what's neutral now it's a photographer if you're the one taking photos one of the best investment you can get is a great card of some kind so if you're doing a portrait shoot or a shoot of any kind somewhere where you're uncertain about lighting conditions make sure that one photo has the person holding or the great card propped up and then you khun taken adjustment layer click on that gray and then apply that same adjustment to other images this way it's just it's helping me with instead of doing a complete one hundred percent guests it's narrowing down the choice is a little bit to finish this off I would go back to the color sampler tool and hit this clear all but because I don't want not that they do anything but they're just a little distracting to have little number of symbols on there and by the way before I do that let me just point out I took this wakes I didn't need it but when you have the info panel available to you moving the eyedropper normally you see how the top figures air constantly changing as I'm going over different colors but the ones that I put remained fixed so is telling me these are the color values for those three samplers that you put on there as a frame of reference which will use in another technique I can also move around and see different values in different other spots if I want to as well I'm gonna clear these off but that's what they info pala does again will take more use of that shortly now to suggest that any one of these methods is better than another it really comes down to what you're trying to do if you're trying to be more specific about us that is just taking a guess this will least narrow down the choices a little bit let's go back a step here I'm gonna actually now they've done this delete all this information because sometimes when there is this kind of a color caste or something of that nature you might not on ly want to worry about the mid tone great point but also make sure that your highlights and shadows are all looking nice in that will everything so one of the ways we can do that it's built on the same principle where I start off with a threshold adjustment layer and I go all the way to the left and as I start to move the first areas that appear are going to be the darkest spot so I take that color sampler too and I click there to say that's the first but then I go all the way to the other end and the first spots it'll appear are the highlights on this image so then I click on second one there then I go back to this concept that did a second ago right a new layer fifty percent gray different sme owed that to our throw a threshold adjustment lair and I find the third point so now if we get rid of this stuff again and I go to something like levels I'm still doing his adjustment layers because I want to make sure that I'm not doing any kind of permanent decisions here so I have three I droppers I just have to remember the order in which I did it all though hopefully should be fairly apparent that if you look at it the number one should be over something very dark and the number two should be something over quite bright if it doesn't look like that then you just said in different order so you just have to remember I know that I did it black first so I take the black eye dropper and I click on that black sampler I take the white eyedropper and click on that one and you see already how the color caste has gone a little bit sometimes even doing that is going to help then taking the gray eyedropper and clicking on that third one will just help finalize it so now we have gone from this to this in a way that was a lot more technical than me just going I think they're so I mean there's nothing wrong with that the pain what you're trying to do in this case technically that is the brightest area but now I find my eyes are being a little too drawn to it because we tend to look at the latest spot so in this case I think I might pull that back a bit because it's almost a little too much because I'm really trying to look at the subject not that white bright part that's over her shoulder so this is a an example of why we have to always be willing I think to not only consider what is thie technically the highlight in the shadows in the mid tones but also what makes sense on what looks good it's just like when we talked before in camera raw let's go back to a raw file for a second that at a certain point if you move the sliders you start to get these warning symbol saying you know you're going to either clip this put information the shadows or the highlights and you get those warnings you may look at a photograph and go you know that highlight warning is so off in the corner I don't even notice it that I don't worry about it they're just there to give you some warnings but it's just something that helps and which reminds me of the one thing I forgot to show you earlier with camera raw that could be a bit of a help it's actually a very similar principle to thresh hold if I hold down option are all too before I start moving that exposure slider as I move it now it's showing me on a per channel basis what are the areas are being affected so I could decide again that the first ones they're showing up I don't really care about these ones a little more noticeable and the same thing the other way if I mostly in this case the photo scraps so dark is we're going to really see it but I could see the same thing with shadows so yet another example of our good friend to make better key changing the way that this functionality works it just gives you a bit more visual feedback than that overall saying well now my photograph is lighter or darker

Class Description


There is always a better way to edit in Adobe® Photoshop® – learn new, advanced techniques from expert instructor Dave Cross and develop a faster, more effective post-production process.

In Advanced Adobe® Photoshop® Techniques, Dave will introduce you to a wealth of little-known and under-utilized techniques that you can use to make your photographs really pop. You’ll learn learn new ways to work with:

  • Layers and masks
  • Composites
  • Type
  • Camera Raw
  • Color grading

Dave will show you how to speed up your work with luminosity masks and how to be more creative using the Blend If sliders. You’ll see how non-destructive methods – including smart objects, adjustment layers, vector shapes and smart filters – can boost both productivity and creativity. You’ll also get lots of great tips on automating your work.

Open up a world of creative possibilities – join Dave Cross for Advanced Adobe® Photoshop® Techniques.


Software Used: Adobe Photoshop CC 2014 15.0

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