Digital BW, The Print

> 8 bit  to 16 bit conversion is so straightforward it's hard to
> imagine why it would be better to do it before sending data to
> OPM.   

I am purely speculating here ... but one can imagine an 8bit->16bit
conversion that is not quite as straightforward and might create
a better image.  The idea would be to make the hi-byte of the 16bit
value equal to the 8bit value, and then put a random value into
the low-byte.   This has the effect of reducing "mock bands" at the
transitions between the 256 values; it is frequently used in 
computer image generation systems.  However, I'd be very surprised
if Photoshop does this when you convert "mode" from 8bit to 16bit,
in which case this wouldn't explain the supposed improvement from
OPM when you give it 16bit images,

John