16bit vs 8bit for prints

[Terry]

A photographer friend of mine processes everything in Photoshop in 16 bit
RAW. When he wants to have a print made he changes the image to an 8 bit
tif. He says that the reason for dropping to 8 bit is that most photo labs
have 8 bit printers.

It seems to me if you are going to switch to 8 bit for the print, you might
as well have never started in 16 bit in the first place. Don't you lose the
extra dynamic range, etc. as soon as you make the change? It doesn't makes
sense to me. What would happen if you sent a 16 bit file to be printed?
How much larger would the file size be - twice the size?

[rafe b]

I doubt there are any inkjet printers that can use
16-bits and in any case, the Windows driver interface
doesn't allow 16-bit print files -- at least that's
what I've heard.

A 16 bit workflow is another matter -- easier to
defend on theoretical grounds if not from actual
observable benefits.

The idea behind the 16-bit workflow is that the
extra bits will minimize the cumulative effects
of rounding/truncation error in the course of
several radical color transformations (eg.,
curves/levels/saturation, etc.)