b&w srgb colour space help!

[itf]

I have a whole lot of scanned black and white negatives and am editing the 16 bit tiffs. The color space is gray and colour profile is gray gamma 2.2, the files are around the 42mb mark.

I'm experimenting with darktable and a trial version of photoshop. After editing I'm trying to save tiff and jpeg copies with srgb profiles.

This works but the resulting tiffs are three times the size of the original and the jpegs seem larger than they ought to be too. I think this is because the color space is changed from gray to rgb when the profile is changed to srgb. :bang:

I can't figure out how to keep the space as gray with an srgb profile, in fact with darktable I can't figure out how to even keep the original gray gamma 2.2 profile.

Any tips? Any recommended software?

 

[itf]

Ok, so I'll start answering my own question. I've now figured out how to change the colour management stuff in photoshop. Changing the profile to sGREY from sRGB returns my tiffs back to their original size (42mb instead of 126mb with the 3 channels of rgb). So I have to find out if an sGRAY profile is going to work for the printer.