Tip for B&W conversions with PL3

DxO PhotoLab Tutorials, tips & tricks
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I discovered a trick that allows me a greater degree of control over B&W conversions in Photolab 3.

I’m used to the B&W conversions using Photoshop CS6’s Adobe Camera RAW (ACR). With a B&W conversion, you are allowed to adjust the luminance of the various colors (red, yellow, green, cyan, blue, and magenta) in the original image. The adjusted image is the one that is converted to B&W.

PL2 has a similar capability of adjusting the luminance of selected color ranges, but the conversion to B&W (under Style - Toning) occurs before the HSL control is processed; once the image is B&W, the HSL control no longer sees the colors in the image; HSL adjustments have no effect.

With PL3, I created a preset that only affects the new HSL control; what it does is set the saturation of each color to 0 (leaving everything else at default value). By applying the preset, my image becomes B&W; however, after the preset is applied, I can adjust the luminance of the individual colors.

This doesn’t work with PL2. Luminance and saturation are hooked together in some manner such that when saturation is 0, luminance changes do nothing.

One problem with this scheme is that, while it creates a B&W image, I don’t know that it does so in a manner that is compatible with the eye’s sensitivity (which is usually calculated as luminance = 30% of the red channel, 59% of the green and 11% of the blue). In addition to creating a preset with the saturation set to 0 for each color, it might also be necessary to adjust the color ranges and their luminosity. By working with some reference color image and its properly converted B&W equivalent, it might be possible to create an accurate B&W preset. In the end, this might simply reproduce the results of Style - Toning; B&W, but with the ability to tweak the conversion that is not otherwise possible.

The controls appear to be in the order of the color pipeline. For example, color changes from RAW White Balance are fed to Color Accentuation, then to Color Rendering, Style - Toning and finally HSL. Since HSL is after Style - Toning, B&W toning eliminates the colors HSL would affect. I suspect this was done because one might want to apply HSL adjustments for Style - Toning: Landscape or Style - Toning: Portrait. For Sepia toning, HSL adjustments aren’t that important, and putting B&W toning ahead of HSL is counter-productive.

The DxO people might have created a more flexible application simply by removing B&W from the toning operations and making it a toggle after HSL.

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Thanks for passing this discovery on - it sounds really interesting !

Would you be willing to share your Preset (by uploading to here) ?

Regards, John M

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I have doubt that this is the right approach.
PL proposes B&W presets you can adapt.

FilmPack proposes color channels editing for a total control.

Pascal

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Hello everyone

This new flexible control with HSL black & white conversion is the result of the refactoring of Luminance and Saturation algorythms.
We introduce that on purpose, to allow each channel to act like a real channel mixer now, when setting their luminance on a desaturated image (meaning -100 on global channel).

You can now also get partial saturation very easily when starting on -100 saturation on global channel, and setting a specific color range to 50 (in order to get the original color), or even by pushing a bit further if you want to oversaturate.

Enjoy :wink:

The DxO Team

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Hi, Pascal,

What specifically do you mean by “right approach”? RIght and wrong are usually terms applied to things like math and science, not art.

There are multiple ways of converting to B&W. The one I mentioned is a common one, known as Rec. 709 (see https://en.wikipedia.org/wiki/Luma_(video)).

Adjusting the B&W conversion through the HSL control (really, just the “L” part) has been around for years in Adobe RAW and Photoshop. I’ve found it useful and I’m sure others have as well. It’s just another tool. No one is forced to use it.

The B&W presets in PL don’t include any magic. They all seem to work off of Style - Toning: B&W, which locks out the HSL control. I found one odd one: B&W: Dense. This one sets the HSL “All” color saturation to 0. Why? I had to dig around a bit, but I found out it uses the Tone Curve’s ability to independently modify each of the RGB channels.

What’s strange is that it appears to be pipelined after Style - Toning and before HSL. I guess I don’t understand PL’s pipeline, since Style - Toning seems to precede HSL. In any case, even with B&W toning, the image appears in color, so the HSL “All” (or now, Master) channel needs to be desaturated to keep a B&W image.

This is exciting! Working with channels is not the same as working with color ranges. On the other hand, we get a lot more control over the conversion to luminance than with just a luminance slider. And it doesn’t require a preset! And it works in PL2! It might also be a way to solve the Rec. 709 B&W conversion problem.

Using the Tone Curve doesn’t preclude using a preset like the one I proposed. Some things might be easier to achieve one way vs. the other.

As for Film Pack, I don’t own it, don’t plan to buy it, and can’t address its effectiveness as a solution for B&W conversions. If it works for you, great.

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Hi, John,

I’d be happy to share a preset, but I do want one that, by default, creates a Rec. 709 B&W conversion (see one of my other posts for a link about Rec. 709). This would require a test image and some futzing around. Stay tuned.

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Thanks. I think this confirms my findings and answers my question PL3 HSL tool and black&white

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Yes, it looks like we were chasing the same problem. What’s interesting is that I missed that desaturating the master “channel” (white) would still allow the other colors’ luminance to be altered. This is simpler than using a preset and it doesn’t miss any colors.

As I’ve mentioned, desturation is typically not the same as B&W conversion.You can observe this by setting the master channel to 0% saturation and then turn the Style - Toning: B&W control on/off. Some images change a little, some a lot.

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i think commen for people who a used to colorgrading techniques :slightly_smiling_face:
I am pleased with the fact that we have several methodes in DxO-PL now to create a B&W or B&W and colored objects.

  • The mask invert is a major step in controling isolated parts of the image not only color but also other things asblur
    The HSL tool is that powerfull that a non trained person in colorgrading can find the blunt and easy visual seen adjustments but not the careful adjusted colortints/HUE corrections it also can deliver.
    This tool has enough for a tutorial on its own.
    replacing color, enhancing a colorrange, create a post layed colorfilter by white channel and normal you don’t have in white channel luminance and uniformity but (if i round the color channel full round you still have the three sat/lum/uniform sliders active, three sliders and three controls as in huebandwidt (channel) feathering of overlapping channels. endless playing time :slightly_smiling_face:
    The old HSL i didn’t catches it’s use for me it didn’t pulled me in using it but the new is fun to use and you can go wild in changing colors and or saturation/lumination/uniformity and that 8 times plus a White full hue band channel. To master this tool in it’s full capacity some tutorial and guidens is appreciated. HINT hint hint.:innocent:
    And Silver effex and style toning and filmpack W&B’s

.

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I see you are expert in the subject :wink:
I reacted on “desatured” (only).
I was not aware of the “Luminence” relevant.
Pascal

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Hi, everyone,

I created a test image with strips of red, green, and blue with full saturation and luminosity varying from 20% to 100% in steps of 20. At the end is a gray strip, with the same luminosity steps.

To the right of each strip is its Rec 709 B&W conversion value. To review, the red channel is 30% of the resulting gray value, the green channel is 59% and the blue channel is 11%. For example, a 40% Red would be converted to a 12% gray (40% x 30%).

I loaded the image into PL3 and set the Master color channel in the HSL control to completely desaturated (-100). The result I saw was that each color strip exactly matched the gray strip next to it. PL3 appears to use Rec. 709 for its Master channel desaturation.

(Oddly, Style - Toning: B&W does not appear to follow the Rec. 709 conversion rules. There’s nothing wrong with this. Photoshop’s CS6 B&W conversion also does not follow Rec. 709. The rule is based on the sensitivity of the eye to the various colors, but that doesn’t necessarily make it the only useful conversion.)

You can now adjust the other color “channels” (I think the word “channel” is misused here—these are colors or color ranges) to refine the B&W conversion.

Bottom line: There is no need for a preset. Just desaturate the Master channel in the HSL control. Skip the Style - Toning: B&W control.

You could also modify the colors with the Tone Curve by manipulating the individual channels (in the correct sense of channels, i.e. R, G and B). One caution is that, for example, changing the red channel doesn’t affect the green or blue strips (as expected), but it does affect the gray strips because gray is created from equal amounts of the red, green and blue channels. Changing red in the HSL control, on the other hand, does not affect the gray strips at all.

Here’s the test file I created, in case you want to try out any of this:

Color Strips.tif (7.4 MB)

What about PL2? Sorry, none of this really works in PL2. Desturating the All “channel” does not do a Rec. 709 conversion. Every primary color is converted to gray equally. At full brightness and saturation, each color is converted to 50% gray. The individual color ranges have no effect once the All “channel” is desaturated. Sorry—HSL is seriously screwed up in PL2.

Thanks to everyone who helped me improve this tip!

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This is very interesting - thanks, @freixas!

I recently used PhotoLab 2 with FilmPack 5 to convert a certain color image to black and white. Yesterday, I experimented with using the new PhotoLab 3 HSL tool instead of FilmPack’s channel mixer. The HSL tool acts on the color channels a bit differently, as one should expect - and just about as effectively. I got close to the same result and could probably refine it more precisely than with FilmPack if I want. Having FilmPack’s extra contrast adjustments helps a lot, though. I love it!

I imagine that some might want the aid of a mask showing which parts of the image are being affected, but I’m perfectly happy eyeballing it.

I ran into an odd glitch. A couple of times, after playing with the range and feathering of a given color channel in the HSL tool and then resetting these to defaults, the luminance adjustments stopped having an effect. Switching colors a few times and going back again to the one I was working on would get it working again. (Windows 10) I can’t be sure how easy this is to reproduce without a lot more testing.

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I was looking for an alternative to creating B&W images, to teach at our photo club, for those who do not have FilmPack.

As you say, the HSL tool in PL3 does an excellent job in “desaturating”, whilst still allowing tonal changes in the channel mixer or the tone curves. It also means that, with FilmPack, should I not want to start with a preset film, I can equally well apply a coloured filter to the now desaturated image and get the effect as if I had put a coloured resin filter in front of the lens at the time of shooting.

Thank you for pointing this out :smiley:

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Joanna, have a look here: PhotoLab presets for FilmPack 5 film types are now available!

sigi

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@Sigi,you need Filmpack for those presets you point to.
See text above the presets.

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Peter - I have filmpack so I can not test it. But I understood that Mark created Presets based on the Filmpack settings. Now these presets should hence work with out Filmpack or?

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Thanks. I’ve already downloaded and installed them. The advantage is that you get to preview the film effect before choosing, which is very useful.

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What you call the Rec 709 B&W conversion (a term from the video world) is very important for retouching. Conny Wallstrom has a nice video which illustrates the differences between various kinds of B&W conversion. And here’s Lulie Talmor’s article on using a B&W helper layer for dodging and burning.

Of course if your goal is to use B&W conversion for artistic effects then preserving the relative perceptual luminosity is not always necessary.

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quote from Mark in the post:

Of course, using these presets will only work if the FilmPack 5 plug-in is installed.

What he did was create from Filmpack a partial preset (so no other settings are effected , and used every film type to save as preset so you have all as “preview” in the preset tab.
Like the others as landscape, portret, dxo standard…

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Alas, that “odd glitch” I mentioned above has continued to occur while making other adjustments to RAW and TIFF files. The Viewer window stops updating as adjustments are made. Reported as a bug.