what is the best way to boost the colors (saturation)


#1

Hi,

as far as I can see, in RawTherapy there are (at least) three way to boost the colors or increase saturation.

  1. In Exposure / Exposure / there is the Saturation-slider - this appears to be the most “brutal” way

  2. In the Color tab there is the Dynamics slider (I am translating from German - not sure whether is correct)

  3. In /Exposure / Lab-adjustments there is the chromacity slider

Especially between the last two options, I do not see any difference.

What are the differences between these tools and what are their advantages and disadvantages?

Thanks in advance for the answers and

regards from Vienna

A.


(Shreedhar Inamdar) #2

The chroma slider in the Residual Image tab of Wavelet module, the A and B curves of LAB module in the exposure tab plus the CH curve in LAB are some more options to increase chromacity. The last two can be used for increasing chromacity of specific hues.


#3

Ah, thanks! The a and b curves in the Lab moduls are very interesting. The other two options you mentioned I did not quite understand.
Thanks anyway!
Edit: Now I understood the CH curve as well. RawTherapee ist ingenious!


(Jacek Gozdz) #4

I was in need of severe saturation boost some time ago, and here are my findings:

SATURATION from exposure tab creates colorfull bloches on neutral colors. Avoid it.

VIBRANCE may create grey bloches on skin. Use with care.

All 3 sliders from 2002 CIE (SATURATION, COLOURFULNES, CHROMA) tend to shift hue. Use if You know what You are doing.

CHROMACITY from LAB tool - no problems found. Go for it.


#5

Yeah, thanks, thats what I thought. But its the same in Photoshop, right? All satuation-tools but Lab-Mode are crap.


(Glenn Butcher) #6

The single thing I found most effective to achieve the color saturation that satisfies my soul has been to jump whole-hog into color management. Since I started using a calibrated camera and display profiles, and a high-gamut working profile, my colors as-shot are looking good enough. You may already be doing this; just thought I’d bring it up for completeness.

Now, when I feel the need to mess with saturation, it’s to introduce unrealistic artifacts. For that, any old crap saturation tool will do… :smile:

+1 to @cuniek and LAB Chromaticity; while I haven’t used it, the math makes the most intuitive sense relevant to the objective.


#7

Well. Actually I am already there (color managment, but my camera is not profiled). Though, in my opinion it is a matter of taste and style. Usually, in a RAW file, colors are not very saturated. I prefer it more colorful. Color is much better when you adjust exposure and contrast. But, especially in RT, I think using Lab chromacity is smarter than just adjusting contrast with the contrast slider in RGB.


(Glenn Butcher) #8

Ah, the colors are there, you just have to treat them kindly… using a high-gamut working profile helps.

Here’s what I get starting with assigning a calibrated camera profile, converting to Rec2020 for editing, then to sRGB for jpeg output:


#9

I know.
How do I calibrate a camera?

The flower is very beautiful. As I said: colors are a matter of style.

On the other hand: calibrating a camera is basically the same as editing the “uncalibrated” raw file or applying a pp3 - I mean in a color profile, there are curves for the channels, for the saturation etc. - or am I missing something?


(Glenn Butcher) #10

@betazoid, after my experience, I think the overall thing to aim for is to protect the colors the camera is capable of presenting, so you don’t have to consider the saturation tools to restore them. So, I think the tasks, order of importance, are:

  1. Shoot raw. Starting with a sRGB JPEG has truncated your colors already, compelling you to dial them back in with the saturation tools.

  2. Use a large gamut working profile in your editing, like ProPhoto or Rec2020, convert to sRGB only when ready to save to jpeg for viewing, or to the particular printer profile for printing.

  3. Calibrate your display. It’s hard to gauge what you’re getting until you do this. My displays at home are decent, close-to-sRGB, so I didn’t notice the importance of this until I looked at some of my images at work, on three less-than-stellar LCD panels. Doing this requires access to a measurement instrument like a ColorMunki, but I found the investment to be worth it. Others might put this task higher on the list, and I’d be hard-pressed to disagree.

  4. Make and use a calibrated camera profile. Actually, this is probably not as important as #1 or #2, as all the raw converters I know have measured data for most cameras, but I don’t think you have sufficient control over the process until you do so. Making one is rather simple, you just take a well-exposed shot of a reference color patch target, and use the FOSS Argyll software to make a ICC profile that you assign to your raw camera file before you start editing. Most raw converters have a dialog somewhere to do this assignment.

Now, I’m still figuring all this out myself, but this is the sum of my learning to date.

Thank you. It was really the rich greens in the leaves that caught my eye; the flower made a good counterpoint. Now, I do manipulate colors arbitrarily sometimes, but this image’s colors are based completely on what I described above.


#11

Thank you. It was really the rich greens in the leaves that caught my eye; the flower made a good counterpoint. Now, I do manipulate colors arbitrarily sometimes, but this image’s colors are based completely on what I described above.

Which lens did you use for this photo? In my experience, it is above all the quality of the lens that determines image quality, especially the colors. In this case, this is the most important question for me.
I am trying to guess: more Zeiss than Leica, maybe Canon L (100mm?), or Nikon?
(If you have experience, it is possible to recognize specific lenses, especially (like in this case) if the photo is not too heavily edited.

Well, I like old lenses for instance. They are not expensive now but they used to be when they were new. Often they have some kind of special effect, special color rendering or special bokeh.
But: there are RAW files, which look grey at first but you can bring out a lot of color if you edit them. And there RAW files, which do not look bad at first, but you cannot improve them with editing significantly.
E.g. photos that I took with an old Helios 44 first looked quite grey, especially wide open. But they are magical when you edit them…


(Morgan Hardwood) #12

Re @ggbutcher
Point 1, “shoot raw” - absolutely, because it lets you decide what happens to the colors.
Point 2 “use a large working space” RT uses ProPhoto by default, though I’m not sure how relevant that is - I recall reading something about it not mattering for some reason in RT - @jdc would know more.
Point 3, very much so.
Point 4 - you don’t need to make your own camera profile for most situations, because RT ships a growing number of high quality DCP profiles, and the difference between a dedicated profile made for shooting at midday in northern Sweden in winter or one made for shooting in the afternoon in southern France in summer is quite insignificant when compared to the overwhelming effect made by the other tools and steps in your workflow.


(Glenn Butcher) #13

Nikkor 18-140mm, at 140mm… I use a so-called super zoom because 1) I mainly shoot railroad subjects, can’t be changing lenses amongst dust and moving machinery, and 2) don’t have a lot of budget for photography. This particular image probably doesn’t challenge it because the corners are in shadow already (hides vignetting), and there are not that many sharp edges with high contrast to display chromatic aberration. For my purposes a very nice lens.

Regarding old lenses I still have my Nikon F2 with the 28mm, 50mm F1.4, and 105mm lenses, three very nice lenses. Don’t have much use for them on the D7000, except as macro lenses with extenders to accommodate the mount mismatch.


#14

You think you want more saturation, but it might really be more differentiation of colors. For the latter, apply S-curves on Lab-a and Lab-b.


(Desmis) #15

What a tricky question as the choice of working profile ?

Some elements to bring water to the mill!
You would think that the better the profile, the better it is, hence the choice of Prophoto.

But we are not sure that the data of the device fits well in Prophoto, moreover Prophoto contains colors outside the visible spectrum.
the use of Prophoto will lead in some cases to make the sliders inactive when we refer to the luminance RGB, whose blue coefficient is close to zero.

Today the majority of the screens has a gamut close to srgb, and in some rare cases AdobeRGB, can be in some cases a little more, but one is very very far from Prophoto
Today the majority of printers have a gamut lower than srgb, and in some rare cases some colors can reach Widegamut, but also one is very far from Prophoto

When one calibrates his camera, to elaborate a profile (ICC or dcp), in the majority one uses a colorchecker, whose almost all the colors are close to srgb.
All the colors outside this case are extrapolated and therefore probably wrong, except if we use a target rich in colors close to widegamut (the maximum of printers).

Moreover it is not because a camera profile (matrix or ICC or DCP) is wide that it contains all the colors and moreover the renderings are probably nonlinear.
In synthesis and not in conclusion I think that choosing another working profile would be interesting for example RC2020, or Widegamut.
My preference is towards WG which has a superior size superior in the reds.

Now as for the best way to saturate, it depends …
if you are a Cartesian scientist, you will choose Lab, who also has a Munsell correction, from a mathematical point of view the rendering of the colors will be almost perfect
if you admit that our brain and our eyes do not respond only to strict laws, but that a part of subjectivity exists, in this case prefer Vibrance or better still Ciecam.
I did not add at the end of the Ciecam a module Munsell, we could do it but it would go against the meaning of the work of the researchers

But what is on it is that the worst method is saturation in RGB modules (exposure)
:slight_smile:
jacques


(Sebastien Guyader) #16

Thanks Jacques! I don’t know why, but subjectively I almost always avoid increasing saturation in RGB. In general I use Chromaticity in Lab*, or sometimes a* and b* curves.


(Desmis) #17

@sguyader

Hello Sebastien
Using saturation RGB, also modify luminance and contrast, in some cases it may be usefull, but technicely it’s bad

Using “a” and “b” curves, for me, it’s for special effects, because one difference leads to change hue, but as above, in some cases it’s useful :slight_smile:

PS: je rentre d’un séjour de 15 jours à la Martinique, belle île, peut être des plages plus “accessibles”, mais point commun avec la Guadeloupe la circulation est “infernale”, même peut être pire :slight_smile:


(Raymond L Payne) #18

Dear Sebastien, etal:

Saturation is not only subjective but fraught with false assumptions. Saturation should almost always be the last slider to tweak. On simple editing programs or where the terms are “muddied” in definition. You figure out where luminescence is handled.

  1. Start with brightness and usually back off on the slider which seems counterintuitive.

  2. Move to Hue (3 colours) flattening out the amount.

  3. Pull back on Gain.

  4. Increase Contrast gingerly.

  5. Shift Saturation not more 15% or whatever your program calls it.

The key is the “Brightness” control. Just saying.

RAYMOND