Re: [darktable-user] I think I found a bug:

2020-09-03 Thread Marc Cabuy
Karim, Terry, Indeed clear explanation, Karim. Thank you. May I additionally to Terry's question (32-bit tiff export) ask whether exporting in a - wider than AdobeRGB - colorspace would be more beneficial too ? (Of course if that other photo editing program supports the wider colorspace and can

Re: [darktable-user] I think I found a bug:

2020-09-03 Thread Terry Pinfold
Thanks Karim for explaining floating point in an easy and useful manner. Can I ask, when you export an image from DT for further editing in programs like GIMP would you suggest 32 bit FP or is there little benefit? On Thu, 3 Sep 2020 at 07:04, Top Rock Photography < ka...@toprockphotography.com> w

Re: [darktable-user] Channel mixer bug?

2020-09-03 Thread William Ferguson
https://github.com/darktable-org/darktable/issues/5578 On Thu, Sep 3, 2020 at 1:18 PM Mikael Ståldal wrote: > Thanks, good to know. (Would be nice if this was documented though.) > > /Mikael > > > On 2020-09-03 18:12, Matt Maguire wrote: > > The problem is that the channel mixer has a clamping f

Re: [darktable-user] Channel mixer bug?

2020-09-03 Thread Mikael Ståldal
Thanks, good to know. (Would be nice if this was documented though.) /Mikael On 2020-09-03 18:12, Matt Maguire wrote: The problem is that the channel mixer has a clamping function which limits the values that are allowed to pass through. This is not appropriate behaviour for the scene-referre

Re: [darktable-user] Channel mixer bug?

2020-09-03 Thread Matt Maguire
Le ven. 4 sept. 2020 à 02:21, Graham Byrnes a écrit : > If you stick to "graymode" or the color modes (outputs R,G,B) it should be > fine: there is a bug that clips large signals to 1, which is really a bug > but has potentially been incorporated in many models. Certainly if you keep > the sum of

Re: [darktable-user] Channel mixer bug?

2020-09-03 Thread Graham Byrnes
If you stick to "graymode" or the color modes (outputs R,G,B) it should be fine: there is a bug that clips large signals to 1, which is really a bug but has potentially been incorporated in many models. Certainly if you keep the sum of values to 1, it should rarely cause a problem. For HSL, yes, t

Re: [darktable-user] Channel mixer bug?

2020-09-03 Thread Matt Maguire
The problem is that the channel mixer has a clamping function which limits the values that are allowed to pass through. This is not appropriate behaviour for the scene-referred part of the pixel pipe, as it can result in exactly the symptoms you report. The devs are aware of this, and there are mul

Re: [darktable-user] Channel mixer bug?

2020-09-03 Thread Mikael Ståldal
After playing around with the channel mixer on some pictures, I get an odd effect sometimes. Just enabling the module with default settings sometimes affects the picture, the histogram jumps to the left and I lose detail in the highlights. Seems to happen when I also use filmic RGB. Is this int