Raw Therapee Basics: Curves & Histogram

yes mother hi guys and gals and another bit of bra therapy an advice for you and today what we're going to do is look at curbs and because eats a question I've been asked quite a few times over voice 3-4 weeks since I started doing these raw therapy videos and yeah people sort of get their ads around why these two curves so we're going to explain why these two curves but we going to explain a little bit more we're gonna look at the curve types and the sort of curve modes if you like and the other thing we're gonna do is look at this the histogram now everybody who's I used to any other raw processor or Photoshop deben is used to a histogram the only thing is the histogram in bra therapy is whoo it's a wee bit special it really is and I'm not going to do a drill down on to the histogram but I'm just going to show you one or two little things on the histogram that'll prove very very useful to you so I think the first thing I'm gonna do is start off with the old curves and he we've got this I photograph of a dragonfly bit of a strange color variant of you know he's supporting the cloudy remember whether he's a blue tile already common blue but he said it's a color form of that one of those two species and lovely little thing very very dainty sorry about that one we've got over here the tone curve one and town curves two under the exposure tab and I'm using these macro images in the previous video and in this one because they illustrate the usefulness of curbs when you've got an image which is fundamentally very very fine high frequency detail surrounded by an absolute boatload of low contrast low frequency detail these are V this very smooth background we all need to use curbs and I'll just tell you something about curbs you have which nobody on YouTube ever tells you virtually everything you can do to an image o beat in Lightroom or or therapy or indeed Photoshop or anything else there's loads of different adjustments you can do and they all go under the different guises of different names etc etc and they are all at the back of it curbs adjustments they're either global curves adjustments individual channel curves adjustments or individual tonal range adjustments and localized adjustments within your image be they based on terminal color but at all a down curves adjustments at the end of the day curves adjustments Drive every other adjustment in Photoshop Lightroom or or therapy etc there isn't called curves yes does well nearly every one of them anyway so just to get back to curves and try and keep this all nice and simple we have linear standard flexible parametric and my personal favorite control cage and what we're going to do is we're going to go through each one now linear doesn't make any difference to your image in all the words the curve is turned off so linear is of no interest to us let's go to standard now a sort of standard tone curve like that you might think is quite familiar you can see we've got a general histogram of the image as a taste now I'm sitting here in the background I'll do you think about standard term curve is this if I sort of grab one point and a lefty top yes we get a Bezier curve coming from our high Y point down to our black point through this point we've just pulled on now if I go and put another point on the curve and drag it me all the way to make an S shape sort of contrast increasing tone curve and you'll notice saturations gone up as well but we'll come to that in a minute if I wish to then go and put another point on you can see if I remove that it has a really big effect on all the rest of the curve and it's very difficult to control a standard sort of cubic spline curve such as this very very very difficult so we'll just neutralize that curve and then we'll go on to the flexible curve and we'll try and emulate the same adjustment as we did before rather like that and like that okay so we've achieved fundamentally the same result as we had before however if I now go and put a third point in there you can see that as I remove that third point up and down it doesn't have the same effect on the rest of the curve that's a subtle effect but nowhere near as great as the standard curve it's a little bit more constrained within the local adjustments area that you're trying to adjust we will now receive a curve and put it back to linear in other words it has no effect on the image and then we'll go and have a look at the next type of kids we can have which is parametric now you've got access to both a normal standard cubic spline curve inside of borax of library but you've also got access to a parametric curve now a parametric curve just in case you don't know where they are in lightroom let's go and open this image in Lightroom and we've got to do a load of adjustments to get it to look like that they agree that there's Lightroom's initial demos akin in the image and it's bloody terrible but if we come to the tone curve you can see we've got our usual as you've just seen a cubic spline curve but if we click here on this little square inside a white room we can change it to what you call a parametric curve where we can set the highlight range we can set the shadow range and then we can come in and make individual adjustments to the highlights and the lights and the darks and the shadows themselves and you get this a little gray area coming over the curve which shows you what area of tone or what tonality you're going to be adjusting so you've got access to the parametric curve which works on top of the normal standard sort of tone curves that you used to these are the that one and the two of them work in parallel they don't cancel each other out which i think is where a lot of people get confused about the two tone curves in rural therapy and so we'll switch back to or therapy where we fill a far better looking image and similarly we can set the position of the highlights Wheaton's the positional or desired position for the shadows we can't fundamentally change the shadows they can go darker we make the darks go darker we can make the whites go lighter and we can bring the highlights up if we want it all right so that's a parametric curve I hate parametric curves I just don't like them at all then I've never ever ever ever ever once found a perfect use for a parametric curve never not in all the years I've been processing images so we'll just go and read zero map and we'll come to my favorite curve type inside of roar therapy which is the control cage now I'll just read zero that the control cage is a different beast altogether let's go and do that self same adjustment or try and replicate the adjustment we were making me thought and you can see I've created a new point but you'll notice the curve doesn't pass through that point it passes much lower down it's a much more subdued and subtle adjustment and if we then go and try and emulate by that shape curve again there's fundamentally the same curve but it's a lot more gentle it's a lot smoother and you'll notice you've got these dotted lines here between this point here and this point here but it's actually doing there is a straight line running between these two points but then it tails off in other words he's more favourable to keeping contrast because well you have to remember is with any curve if you flatten the gradient of the curve you actually reduce the contrast and if you flatten it out completely like a flat curve you lose the image in its entirety because it man all becomes the same tonal value in other words you've removed all the contrast from it so we better go in trees around that and so this is why I like and control cage curves because they are very very gentle you can go quite crazy with them and not go over the top and it maintains wherever possible a straight line but Bezier these things in a very very smooth and graduated way so those are the fundamental types of curves that you can use inside a real therapy but now we come to the actual modes now you can think of the curves modes which is standard weighted standard film like saturation and value blending luminance and perceptual for those of you who Photoshop savvy oh I'm probably going to get in trouble with Ingo and all the developers of real therapy for saying this but you can think of these like blend modes in Photoshop but not mm-hmm but you can think of them as blend modes but they're not like any blend modes that you are used to in Photoshop and but you know if you put a curves adjustment layer on to an image and you sleeping the curve you put an S a curve on to a curves adjustment layer and you leave it in the normal blend mode it increases the saturation of the image as well as the contrast of the image if you then put it in the luminance blend mode then all the colors go back to where they were you don't get any saturation increase you just get a tonality a grayscale increase in contrast so you can think of these white blend modes but they melt so if we have this the largest proton which is a little bit on the aggressive side if you have written the standard blend mode with increased contrast but we've also increased saturation now I'm gonna just break here because what I want to do is to now bring in the histogram part of this lesson as I said I'm not doing it a deep drill down into the histogram because there's a lot of useful things about this to Graham in rural therapy it's a lot more extensive and a lot more technically revealing about your image than any Instagram I've ever come across at any rate but if we go over to the histogram model d rizal just widen it out a little bit so we can sort of get a better view so this is where we're looking we've got the hi to me SAP bottoms off so we've got nothing in the histogram there's the red channel of the image as it stands at the moment there is the green Channel and there is the blue Channel there is a little button here which he says when you hover over he says toggle between linear log linear and log log scaling now anybody who's been watching the government graphs I'm for Co vid 19 but will actually know the difference between linear and log because log curves make things look a little bit lower than linear does some if we were to use a linear scale for this esta gram and then it would be quite tall my advice is to habit in log log it makes a lot more sense the histogram is a bit more usable and actually ends up being divided into stops you can see we've got these little icons as I click this but when it's split on a 45 degree diagonal that is linear but his log Linea where we've got a curve in the eye Colin and he wished he were bigger taller wished he did say up here somewhere what you were looking at but if we now press it again so we've got this lower white Porsche in a smaller white portion then we are actually in log log the useful things on the histogram are this gray button here which if I activate it that is the images it stands at the moment but is the l channel of a lab conversion of the image or lab model of the image as it stands at the moment so this is a little bit like the composite histogram in Photoshop or Lightroom the other thing we can do though see this little yellow button here if we hit the yellow button then we will get this for histogram come up well actually if you do if you can't Balam one and it's in yellow that is a histogram showing the distribution of the chroma of the image the color of the image the colourful mass of the image you can take that as an indication of what are the most saturated tones all the most colorful tones within the image so when you go and make subtle adjustments if it's difficult for you to see if you've had an effect on saturation then that little yellow histogram will actually show you so if I just go back one two before I put this kid on or if I just go and turn the curve off instead of going back one step in the history began turning the curve off and notice how the entire histogram shifty but also the core fulness or the chroma of the image is shifted and it's also been slightly redistributed so I'll go and put a control cage curve back on like that I like that get it passing through the midterms I mean as I said before it is exaggerated so this is in standard curve mode so we've got a distribution of higher contrast within the image but we've got an increase in saturation the other thing is when you processing something with an awful lot of smooth graduations in like a sunset image this standard curve mode can actually give you some quite significant hue shifts within the delicate graduations of for instance a sunset sky and so it's not really a very good mode for a curve if we go to standard way t2 a weighted standard now you'll notice there's a massive difference between the actual saturation of the course especially in this smooth although contrast area if I just go back again so you can see there's standard and notice this yellow HD Graham here ever change it back to weighted standard see how he climbs a little bit but it's not quite so light so it moves a little bit to the left and goes up a little bit so it's still colorful we've had a color increase but we haven't had such a big change if we think back to when this HSV reading here now remember we did actually look at the HSV equalizer last week hue saturation and value or hiking value to luminance or brightness what this weighted standard has done if we go back to standard again we just go on apply it again it's actually biased towards the original the values within the image so it has increased saturation a little bit but not as much but it hasn't affected the lightness values when it's done it shifted the contrast but he doesn't produce quite such a color shift I'm going to put it back to standard again because this is the one we should judge all the other modes against so we just put that back in standard and then we shift to film like you can see in this particular instance it's not really made a lot of difference now on a different image with a different distribution of court and perhaps even a different distribution of the frequency of detail in other words not quite so much or it's such a big expanse of low frequency low contrast detail areas in the image can very well give you a completely different result and result in a considerable jump in saturation so you have to remember that these various curve modes don't always give you exactly the same result in every image which is why you need to learn to play around with them and experiment with them and you'll get a feel for which mode will do what to a particular image and you'll also certainly start to develop your favourites so if we put it back to you standard again and then we come down to saturation and value blending now sutter Asian and value blending this it is a very very useful and is one of the ones I turn to quite regularly because if I just turn the curve off doesn't really make a massive massive difference to the levels of color in the image but it certainly makes a massive difference to the amount of contrast in these areas of higher frequency detail so we'll just switch back to you standard again and we'll come down to luminance now you notice that there was a big jump in this in the position of this chroma histogram we're going to do it again go back to standard and then come to luminance now that is very much like putting a curves adjustment on in Photoshop or a curves adjustment layer in Photoshop and then putting it in the woman in its blend mode or luminosity blend mode very very very similar and fundamentally I find that the luminance bland mode sometimes actually works or feels nicer or looks nicer than weighted standard weighted standard is one of my go-to curves or curve modes so is luminance and flattery or lastly I should say their standard and these perceptual which is supposedly supposedly the one that does zero color change there is the completely unadjusted image there is the image with the contrast adjustment in the perceptual blend mode on this particular image to me it is bumping the saturation just a little bit because if I switch from perceptual back to luminance again you see what I mean it looks a little bit less saturated so the three curve modes that are suggest you look at or keep in mind are weighted standard luminance and be satchel with a control cage type all right so I'm just going to apply what I think is a nice curve it's our easy row that I'm gonna put it back in this standard blend mode if you're like shouldn't decide blend mode but well there you go and I'm just gonna put a simple subtle shape tone curve in there and so we've got an increase in saturation so I'm just gonna drop this into the perceptual blend mode or am I gonna drop it into the luminance blend mode I'm going to leave it in the luminance blend mode so this s-shaped curve here is having virtually no effect on the saturation of the image but it's having a big effect on the contrast of the image now that is the thing what we can do is bring in a second curve and I'm gonna pick a control curve again and I'll just rezero that as I said my favorite curve is the control cage but if you go into raw pedia now they put all sorts of things in there about the control cage um you know if you've got sort of fine point on you can actually really control and create lots and lots of straight lines on the curve I actually never ever ever use more than two points on a control cage curve never because I've got the option to bring in a second curve now a lot of people seem to be confused about the existence of this second curve because maybe easy think if you do something to this curve it'll cancel that curve out not no no no no no no no no no no no nada won't this curve will make adjustments based on the adjustments that are made here so in other words this curve is a has a compound effect on the image based on what's happened then this curve yeah so it's a cumulative thing so what we can now do is seen as we've done on curves adjustment here which is a very very subtle s-shaped curve to control contrast without making changes to Co it now we can make changes to a little bit of contrast and more quick in this instance in this second curve so we could go and apply another curve rather like that and then drop baton maybe film like or weighted standard or saturation and value blending that looks a little bit harsh so what we will do is we will really drop that curve down okay something like that let's turn it off see the image looks it looks nice but it looks a little flat if we just go on put a very very subtle curve on there now and it just adds that little bit of pop to it it's not really doing much for the color we could possibly go and drop that in film like and just give it a little increase in saturation if I go back to where were we saturation and value blending watch this yellow histogram here we drop it back into film like it actually moves the histogram slightly to the right which is making more of the lighter tones just like a little bit more colorful but it is dropping slightly in exposure or in vertical pixel count for each tone so we could do is maybe just brighten the image up just a little bit rather like that and I think that works really really cool so if you are struggling to fundamentally see what's going on with color and with brightness what you can do is actually turn off the red green and blue portions of the histogram so you can just look at the luminance and the core fulness there's a bit a bit bit of a strange do and you can't do that in Photoshop and you can't do that in the light room don't think you can do it in cap one Pro or anything else to be quite honest with you I'm so there you go all we've got left to do to this image now is just blow it up to I want to one view sort of pull it down a little bit so we can see what's going on come over to the D mosaicing panel I'm gonna switch out from a maze to a maze possibly ng4 because remember the ng Thor is more favorable to demos Asian these low contrast low-frequency detail areas and then I'll just go and drop the capture sharp you know I'm very good and I'm quite happy with that image I'm trying to keep it realistic and as life why like as possible and dead to be honest with you I think we've succeeded quite well we could go into the color tab and then turn on the HSV equalizer I need to go in to earth for saturation I might want to just increase the saturation of the Reds and increase the saturation and the yellows a bit to give us an overall increase in saturation in these little red flowers here and then I might just want to decrease the saturation of greens ever so slightly just to try and keep this background under control and yeah there you go oh you've enjoyed that going in the next video this will give you something to look forward to we are going to be looking at these babies I'll have adjustments now somebody did ask me why I favored the HSV equalize it is against all that adjustments mm-hmm I don't that was somebody put it on a comment on last week's video I don't but the purpose of these raw therapy videos that I'm putting up on a youtube channel is to gradually wean Lightroom users on to volunteer or therapy and the HSV equalizer as you've just seen there's got three levels of control the lab adjustments forget these yeah Missy sort of Tin Pan Alley the real power comes from these here and as you can see here we've got one two three four five six seven eight nine adjustments that we can bring to bear within the advanced if you're like all AB controls so that's what we'll be looking at in the next video perhaps might be something else but my main intention right now used to cover this in the next video so if we just come back out to a fit to screen view and we'll push or walk walk back and there we go yeah rule therapy curbs in rule therapy nice and simple a hope have managed to explain it properly for you use this video can go on have a look at the curb Sachin under the expose your tab on raw PD and I'll think you're between the video and what it says on Raw PD and think you'll soon get the hang of it and don't forget use this neat little trick with ace to Graham yeah I mean that istagram very very powerful and so anyway there you go guys and girls hope you've enjoyed that hope you found it useful Tim yeah if you have and you want to see more don't forget yes give us a warrant give us a thumbs up leave a comment in comment section below share it share it I could do with the traffic yeah and yeah if you want more in-depth members exclusive articles and videos don't forget you can always up over on to my patreon channel and start reaping the benefits of my membership site alrighty so until the next time guys and gals stay safe stay well and I'll see you very soon Chiru

Channel: Andy Astbury

Views: 11,744

Keywords: raw therapee, rawtherapee, raw therapy, raw therapee tutorial, workflow, curves, lightroom, photoshop, photography tutorials for beginners, tutorial, photography, raw, rawtherapee tutorial, free software, image editing, process, how to edit, image processing, photo edit, photography software, raw processing, capture sharpening, hsv equalizer, raw processing software, wildlife in pixels, photo editor, andy astbury, free lightroom alternative, Raw therapee tutorials youtube

Id: 3sCGNkR2XGc

Length: 33min 22sec (2002 seconds)

Published: Fri May 08 2020