PhotoLab 8
I often create B&W images with blue skies that I want to be rendered dark, so I add the red filter…
But to do this, I have to revert from Wide Gamut to Classic, otherwise, all I get is…
As I wind up the Density slider on the filter tool, after 110, everything gets brighter instead of darker.
Anyone got any ideas? Or is this just another bug?
PL8.1/Win11 here. For generic B&W renderings the behavior is as expected (maybe too mild), while for other types it is similar to your example. Strange indeed.
EDIT: Same strange behavior for PL7.10/Win11.
@Joanna : what rendering did you use?
Same effect here:
Ideas: Not really…except, maybe, possibly…some tonality shifting takes place in order to preserve details in saturated colours. Even though we only get a B&W preview, processing takes place in colour. Adding saturated colour (red in this case) might be counteracted by the new colour management with its wider space, changed rendering and options.
Remember your lobsters? They might suffer similar effects.
This is getting a bit more complex than we first thought.
Here is a screenshot with the Fuji Acros emulation in Classic WCS…
And here it is in the Wide Gamut WCS…
Notice how the pointer on the slider scale for the Classic WCS is only halfway, at 100.
But the pointer for the Wide Gamut WCS has the pointer at the extreme right for the same value of 100.
This means that I can increase the intensity of the film emulation in the Classic version to 200, which gives this appearance…
Not much difference, apart from slightly darker blacks.
But, if I turn on the red filter to 200 in Classic mode, with the emulation intensity at 100, I get this…
… and, if I increase the emulation to 200, I get…
Not necessarily very useful for this particular image but, at least it does provide an interesting option if required (say for IR images)
As opposed to changing nothing else and simply switching to Wide Gamut is like cancelling both the emulation and filter…
Notice how the maximum emulation density has now switched to only 100.
Curiouser and curiouser.
Using Wide Gamut, the Red filter seems to work as expected, perhaps too mild, on B&W Generic renderings and (to make it even more strange) on ‘Rollei Ortho 25’. Other renderings of BW film or Digital film types do misbehave.
Do you think there’s also something wrong with the Channel Mixer? I had this impression since about PL7.8, but I use it very rarely (like B&W), so maybe it’s only my hallucination.
Is the behavior different with PhotoLab 7 or earlier?
I remember running into problems like this several times before with the channel mixer, filters, and film simulations during EA testing and with new PhotoLab releases. They were bugs and were eventually fixed. Might be that something broke in PL8 or earlier and needs to be fixed now.
Just checked it on my laptop where I still have PL7.6/Win. Related to the @Joanna’s issue with red filter behaviour on the sky – the behaviour is as in PL7.10, PL8.1. It’s an old story, it seems.
The Channel Mixer in PL7.6 seems to work as in recent versions, so I had some hallucinations indeed. Forget my question about it.
corrected version !
I did a (criss) cross test in PL8 with a ProPhoto TIFF file and a converted sRGB version,
each in WideGamut (WG) and Legacy (Leg) working color space,
and used the Black & white film simulation Fuji Neopan Acros 100 (FP).
.
You can download “riwodot colortest I.tif”
.
ProPhoto color space
no filter
with red filter
.
*) Adding a red filter (FilmPack) when set to Legacy also influenced the white point and darkened the whole pic. → Compare and check histogram!
ProPhoto:
WG = 253 ↔ Leg = 231
sRGB:
WG = 253 ↔ Leg = 236
.
Could you explain what you mean by “generic”?
I mean the Type of rendering, just below the Color/B&W buttons and above the Rendering pull down list. With the B&W button active, you have the choice of ‘Generic rendering’, ‘Black & white film’, and ‘Digital film - DxO FilmPack’.
Well, I’ve just run a quick test - again 
and found that the only way to get the expected darkening of blue skies with a red filter is to use the Classic WCS. Without that, nothing I can do: Channel Mixer, Colour Wheel, etc, causes the darkening, except for a couple of esoteric film emulations, which have adverse effects on the rest of the image.
This may very well be why I was struggling to understand the red filter instructions you gave me in my other thread… Nothing really was happening and I wasn’t getting response from the filter or the Channel Mixer as I would expect for b/w conversions.
Tom
Does this mean the ‘Legacy’ selection? What color space does Legacy use?
Tom
Yes.
AdobeRGB
@Joanna, did you report the problem to DxO?
If I remember correctly, you posted an example of FP Red Filter acting on B&W sky, which worked as expected, so I wonder which PL version you used (could not find the example now).
The problem looks somewhat embarrassing.
I thought that the Color Wheel (I mean HSL tool) is applied after rendering (unlike Channel Mixer or WB), so if you choose B&W rendering, HSL should have absolutely no effect. Am I wrong?
Is there a difference when you export the colour versions in wide gamut and legacy from PL as TIF and then edit them with the standalone version of Filmpack?
I tried with FP7 standalone and used the ProPhoto as well as the sRGB version of this pic with the Black & white film simulation Fuji Neopan Acros 100 and the red filter.
The conversion from “ProPhoto” turned out darker (most probably due to the more intense blue) than from “sRGB”.
There was no white point shift as mentioned before.
.
… and the complete experiment
Yes, I have just done that, with a link to this thread.
Only to find that the support site is down 
My examples (RF = Red Filter Intensity) - test photo with 10 VCs:
Sorry, couldn’t upload the RAW because the forum software said it’s too big. It’s over 60MB. The jpeg with no corrections applied (neutral color):
I have submitted a bug report, citing this thread. Received placatory automated acknowledgment…
Merci de votre patience et excellente fin de journée !
