Does anyone have a clue why, after all these years, Nik Output Sharpener STILL does not work on grayscale files? IMO, it’s totally ridiculous that I need to convert to RGB unnecessarily ballooning the size of my file. This might be an acceptable compromise for 35mm film scans, but 8x10? My computer would be gasping for air with a near 1TB file!
It’s hard to say, since DxO doesn’t fully explain its processing and rendering pipelines. This is true of PhotoLab and PureRAW and even more true of the Nik Collection in my experience. DxO acknowledges the problem here, but doesn’t say why:
Which file formats are supported for use with Nik Collection? – Help center
I’ve yet to see any real advances by DxO in how the Nik Collection manages color spaces. Some apps remain broken for me after many years of testing and reporting. The working color space is still limited to Adobe RGB. And as you point out, support is limited to RGB files. I suppose the ultimate reason for this stagnation is that the Nik Collection is primarily a set of plugins for Adobe software. But I’m not sure.
Well, you know that the Nik color correction tools require RGB files—whereas this shouldn’t really be necessary for the Nik Output Sharpener when working with grayscale files.
Given such enormous file sizes, couldn’t you use 8-bit compression—or even try JPEG?
I can certainly appreciate that color tools, like Color Efex and Viveza, require RGB files. But tools such as the Presharpener and the Output Sharpener shouldn’t require RGB color mode, IMO.
Sorry, I should have been clearer regarding those large color files. I’ve only ever come close to 1TB with an edit on a 16-bit 8x10 color transparency. Most of my shooting is on 8x10 B&W film which keeps me in the 100 mb range for a 16-bit grayscale file. But convert that to RGB in order to sharpen with Nik and that file starts getting kind of hefty. I don’t ever post-process in 8-bit and have been known to save out a fully finished file for print as a JPEG.
Hopefully, one day I’ll be able to use the output Sharpener on my grayscale files. A boy can hope, right? 