Digital BW, The Print

I have not read the last few posts on this subject but I thought I'd throw
this out for thought - I myself am still thinking about it (still awke at
1am) and I wish I could consult someone that new the answer!

Sketch the following.  Light intensity on the x axis from 0 to the "standard
illuminant" D50 lighting.  First plot "perceived brightness". As we know
human vision is not linear and you get sharp increases in perceived
brightness at the beginning, flattening ever more off as we approach full
brightness of our illuminant (same applies to all human sensory experience:
sweetness, bitterness, audible volume etc).  From everything I have read
XYZ_Y is about the best model of human "perceived brightness" we have.  So
this plot is best approximated by XYZ_Y and is 100 (or 1 depending on
notation) at the standard illuminant.

Now plot L*.  L* is a linear concept.  As we move from no light to full
light L* moves evenly from 0 to 100.  When we get to 100% of the standard
illuminant, L* is 100.  Does this make sense so far?  I think it does.

Now compare the two lines.  At the low end of the scale very small increases
in L* are associated with large increases in perceived brightness (loosely
labelled luminance).

Maybe I am talking through a hole in my head here but does this answer our
issue about small gradations in  L* at the dark end of a visually pleasing
greyscale?