WhiteWall says, “Please use the black/white standard profile GrayGamma2.2.”
But when I want to import it in the Soft-Proofing menu, it is greyed. What can be the reason please? And also strange, can’t even select it to upload. Also grayed out as in the soft-proof dialog.
P.S.
Here,
similar question and also below a possible solution which is described.
“I made test prints on Ilford black and white, Fuji Crystal Print DP II and Kodak Pro Endura. Soft Proof, using Adobe RGB profile, works very well for the Ilford paper. It is closer to the print than either the Fuji or Kodak papers using their own profiles.”
B&W images can be stored with rendering method settings “RGB” or “monochromatic”.
Without having tested it, I’d say that the B&W profiles are made for files stored with the monochromatic method.
Please note that I write this from memory … which means that the wording might be off.
DPL was unable to handle monochromatic files a few years ago. I had scanned images that I had saved as monochromatic files and when I rescanned and stored them as RGB, DPL was able to display the images in the files.
Found a few profiles with a search. Applying these in Soft Proofing did change the histogram, visible differences were minimal though - as tested with an image treated with a Fuji B&W preset from FilmPack.
I read the links you provided (and others in the forum mentioned) …
So from what I understood
convert the image to B&W as RGB file
( all 3 color channels show the same value )
and then export as AdobeRGB, which is Gamma 2.2
( the SP with ARGB + RI perceptual shouldn’t show a difference, otherwise correct it )
Don’t use sRGB, which is also Gamma 2.2, but some numbers represent different grayscale values (I tested the latter myself a long time ago).
.
WhiteWall points out
Wichtig: Unsere ICC Profile dienen ausschließlich der Softprofilierung und einer repräsentativen Vorschau. Bitte nutzen Sie diese Profile nicht für eine (Farbraum-)Konvertierung und betten Sie das ICC Profil nicht in Ihre Bilddaten ein.
which means … leave the B&W image in AdobeRGB and send it out.
WhiteWall will use their paper profile for the paper in question.
As big prints are costly maybe you can check out the paper but in a smaller size.
A general question about gamma.
With the old tube monitors/televisions the amount of light it produced was not linear with the amount of power send to the tubes.The difference was expressed as gamma, as opposite of linear.
Modern monitors are led based and are linear. To avoid differences between tube and led based monitors a gamma was build in these monitors.
The old Apple monitors had a gamma of 2.2 while the other monitors had a gamma of 1.8. Now Apple switched to 1.8.
What is the meaning of an icc profile with a certain, different, gamma?
That’s known. Question is when the gamma is applied. For me it’s part of the demosaicing proces and as so not adjustable.
That’s why I got confused by the name of the thread. It suggests that gamma 2.2. is something extraordinary.
The gamma correction in PL is above the basic gamma correction.
Are you sure ?
I thought that when exporting linear DNG, only demosaicing process is applied (which in DxO world, as I undertsand, is an AI process** including optical correction and denoising - if enabled).
So any transfer curve should be applied after that (demosaicing).
If not, demosaicing implies loss of datas, and DxO linear DNG would loose datas.
** Is whole demosaicing an AI process ??? - this could partly explain why new cameras take a long time to be incorporated.
(Anyway Ai seems a good way to reverse engeenering when datasets are easy to produce).
Maybe I must correct myself. There’re 2 gamma corrections. The one I referred to is the gamma correction the OS uses. The gamma correction PL or any other converter uses is the correction for the human eye.
It’s not an AI process, just math.
indeed. I thought I had read this on the DxO site but on looking again I can’t find this information. This seems more logical and predictable.
How the OS gamma correction could be applied when demosaicing ?
Isn’t it only applied when display occurs, and so doesn’t alter the image datas ?
Other softwares (not photo softwares) I use keep linear datas for the whole process and only apply gamma or other curves when displaying or saving images (depending of user target choice when saving and display device/target choice when displaying).
I corrected myself. The gamma for the monitor is applied by the OS. The gamma, correction, for the human eye is applied with demosaicing. Normally.
It is not an essential part of the demosaicing process.
So my question remains : how to get a linear DNG that should not suffer data loss ? Photolab get 2 kind of demosaicing process ? A special one for linear dng ?
Other softwares (not photo softwares) I use keep linear datas for the whole process and only apply gamma or other curves either when displaying or when saving images (depending of user target choice when saving and display device/target choice when displaying).
Maybe we should talk about conversion and demosaicing. In that case demosaicing is the process to get the RGB pixels. The gamma and the color conversion is done on these pixels. That process can be called a conversion from RAW to RGB.
How other software deal with these DNG I don’t know. The only thing I know is that photography is a visual activity. I must rely on what I see and that includes the gamma correction and the color conversion.
A general remark on data loss. Mathemetical there is no loss with the gamma correction. The range doesn’t change with the used formula.
Like anybody here I’m not an expert. I just try to do my thinking.