hanshab

elow are examples of before and after the saturate by subtract macro has run

There was a step missing in the macro, which is initially to duplicate the layer. I fixed that and put in more explanations to the macro. The key is the inversion and the subtraction which takes out the complementary colours of RGB to make the RGB more saturated. However what John Rostrow got is typical if you don't adjust opacity and the brightness and contrast of the colours once the subtract mode is applied. This is because in RGB as opposed to LAB, both colours and contrast are adjusted. In the macro I allow you to adjust all these parameters to taste since each picture will be different. The saturation is very deep as is the contrast so those will need to be adjusted. I recommend that you set the global opacity to between 10 to 20 percent saturate by subtract RGB.afmacro

Very nicely done.

I forgot to add that it is a single macro and has to be uploaded from the macro and not the macro library pull down menu.

The saturation of a color is determined by a combination of light intensity and how much it is distributed across the spectrum of different wavelengths. The math for saturation includes luminosity. An interesting way to saturate a photo is using the subtract blend mode. This can be achieved by making a copy of the photo then inverting it. This changes each color to the complementary color. But it also affects the luminosity. You then apply the subtract blend mode. You are in essence subtracting the complementary colors from the original photo that has the effect of saturating the original color. In RGB mode, when inverting, you not only invert the color but you also invert the luminosity. This has will darken the photo colours. So in practice what I have found you may need to change the brightness of the midtones and/or the shadows. You can then apply blend ranges to apply the difference blend mode but I find keeping the highlights from the original works best. I have included a macro here that does this. The macro lets you manipulate the brightness and contrast of the midtones and shadows if you wish. YOU can also manipulate the blend range if you desire. Have fun. Note that this works in the RGB color space but NOT in the LAB color space as the math is different. saturate by subtract RGB.afmacro

I do most of my work in the LAB color space. I then convert to other color gamuts as required. I find LAB useful since it separates color from luminosity so its easier to create masks such as luminosity or saturation masks. I have developed a macro that provides sharpening and color accentuation using the unsharp mask and curves. In the enclosed macro you can adjust the separation of the A and B components as you wish, just bring up the curves adjustment to accomplish. I have also included the selective color adjustment and levels adjustment which I often use to "dial in" the precise colours I want. Just access the respective adjustments once the macro has run. Hans' LAB sharpen.afmacro

here is the algorithm for vivid light. IT is a combination of color dodge and color bur Based on the value of a particular pixel. This blend mode combines Color Dodge and Color Burn (rescaled so that neutral colors become middle gray). Dodge applies when values in the top layer are lighter than middle gray, and burn to darker values. The middle gray is the neutral color. When color is lighter than this, this effectively moves the white point of the bottom layer down by twice the difference; when it is darker, the black point is moved up by twice the difference. (The perceived contrast increases.) Blend > 0.5) * (1 - (1-Target) / (2*(Blend-0.5))) +(Blend <= 0.5) * (Target / (1-2*Blend))

I cannot open your file.. But just going by your text whenever R=G=B, the color is a shade of grey. But if you say Max=Min, is this supposed to be irregardless of if its blue green or red? Ie Max (R,G,B) = Min(R,G,B) it always will involve the lightness as that is always part of RGB so you are setting the lightness to some single value over all colours in RGB. but I can't be sure as your file does not open... Thanks

I keep finding things for you for your camera club: here is a good video on why 32 bit Pro photo is the best..... today.... https://wolfcrow.com/should-you-raise-bit-depth-and-color-space-before-color-grading-part-two-raw-video/

BTW Neutral shooting only affects Jpgs not raw..... I use the jpgs for immediate processing using snapseed but then when I get home I use Affinity Photo. 14 bit raw encoding is what is preferred for raw.;.;; if you want to talk about color then I recommend you look at these web sites . The author is a painter and photographer and he gives a very good overview of color theory. Folks in your camera club might appreciate this.....https://www.youtube.com/user/EverydayHDR/search?query=color+theory be sure you watch both color theory 1 and 2 which are both shown on this page... There are many others on color theory out there but I like this one as Blake is also a painter.....

I have several 6 TB disks a 4 TB and a 3 TB disk... I remember when disk technology for a 8 foot high disk drive was 256 MB..... I also developed computers in the early days and have a number of patents on them ITs come a long way. AS AP works in 32 bit floating point in develop it gives you a good start for any further work you do in the photo or HDR module. I use the HDR module a lot directly from the develop module. You might try working in 32 bit mode in photo as most of the adjustments work in that mode. Many folks think you dont need 32 bit and if your camera only records in 8 bit then that is true but my cameras have a very wide dynamic range with 36 and 45 MPixels as well as recording in 14 bit flash and I can recover a lot .. You really need the dynamic range for that. I have conversed with many photographers on You tube working in Photoshop who insist that 16 bits is enough but watch some of the videos from James Ritson and you will see the benefits of 32 bits. Its not for everyone, most people will be very happy with 16 bit which is what Photo persona works in when you dont select 32 bit mode..... I have to tell you that 32 bit mode is especially useful when doing astrophotography..... I never have to bracket a landscape photo when I work in 32 bit I have always been able to recover the darks when I expose for the lights..... But then I have the right camera for this as well. As far as your comment on the cost of the books. Well, these are textbooks and are expensive...

In affinity photo raw development is done in 32 bit unbounded float in a linear space according to Serif. My camera takes pictures in Adobe 14 bit not 8 bit which is adequate for a raw picture when you record the raw file in camera as NEUTRAL. I find cameras that record RAW in 8 bit less than desirable. But 8 bit makes the file size smaller but you cannot recover out of gamut data easily especially in landscape photography which is what I do. Its when you do manipulations with the camera raw file in either any persona that you need the extra precision. So when you go to the photo persona you could select a 32 bit space with the assistant. Serif went to 32 bit in the develop persona i Believe with version 1.5 as with version 1.4 when you did even tonal adjustments it would blow through the available precision and give very undesirable results. The HDR persona is of course in 32 bit as well and I tend to do a lot of adjustments there. Then you can continue working in 32 bit mode when you go to the photo persona. Of course you have to scale to whatever format when you output the file... There is a video on how to do that scaling as well

FYI I am a former professor of Astrophysics and former director of the Hughes GPS (WAAS) program with a specialty in relativity theory. C* is the chrominance in LAB and is not separable in any RGB color space . I would not convert RGB to LAB you lose something as the RGB color space is smaller than LAB. I always go directly to LAB then only convert to Pro Photo when all the calculations are done. Again there is a loss associated with this but its what you have to do and to print you have to go further to sRGB...... I am still experimenting with going directly to a 32 bit color space and working from there . In the formulas L is the luminosity and one can use a luminosity mask for this; again I refer to Kuyper..

There is no precise way to do saturation masks in any RGB color space because lightness affects saturation and lightness is not directly used in any RGB saturation mask approach I have seen. Using the HSL and HSV adjustments in Affinity is a rather poor choice as this will give significantly different results for brighter and darker images.I do not recommend this approach. It does not take into account lightness. (I am working on a solution in the LAB color space that includes luminosity masks and uses color inversion masks and the difference and or subtract blend modes but I am still working on it.) In LAB luminosity is directly applied and much easier to use the formula there is: which is not recommended as there is no chrominance (C*) relationship to other gamuts from LAB , an approximation to what the eye sees is given by . This is still an approximation the explanation can be found in wikipedia here: https://en.wikipedia.org/wiki/Colorfulness or on any book on Color Theory such as https://www.amazon.com/Color-Vision-Colorimetry-Applications-Monograph/dp/0819483974/ref=sr_1_13?ie=UTF8&amp;qid=1547755006&amp;sr=8-13&amp;keywords=The+physics+of+color+theory Tony Kuyper who is cited in the dialogue above has done an excellent job of getting to the best practical solution for saturation masks and I have been using his approach up to now. He has also done a superb job on luminosity masks

I agree, it really hampers me especially when i try to use the color burn/color dodge blend modes...