Digital BW, The Print

Wow. What a firestorm. Even a claim of gratuitous "name dropping"!! hmph.

I will stand by the following facts (verified by me and others -- yes, my amigo Bruce 
Frazer too -- many years ago):

1.) almost all high-end scanners today scan INTERNALLY at 10, 12 or 14-bits (only 
the cheapest consumer scannersnow  scan at 8 bits internally. Almost NO scanners 
actually scan at 16 bits))

2.) assuming that the SCAN curve is optimal for the negarive in question (i.e. the 
instructions to the scanner, including white point, black point, and shape of curve) 
there will be ABSOLUTELY NO DIFFERENCE between an optimal "8 bit" scan and a raw 
"16 bit" scan that has been manipulated to equal the "look" obtained by the above 
optimized curve -- regardless of the number of bits. 

It can best be diagrammed as such:

scanner (12bit) + optimal curve --> optimal file (8bit) --> printer (8bit)
scanner (12bit) --> expanded file (16bit) --> manipulate (16bit) --> optimal file 
(any bit) --> printer (8bit)

All things being equal, the above two workflows will produce the EXACT SAME IMAGE 
at the printer (i.e. there will no perceptible difference at all)...

...However, I *WILL* conceed the following scenario where manipulating in 16 bits has 
a theoretical advantage (it is certainly not true for most B&W images):

- specifically, the case where one wants to push the image WAY BEYOND what an 
optimal 8-bit scan would deliver, especially using algorithmic means (e.g. equalize, 
extreme curves, etc,).  An example of such extreme manipulation might be what 
Ansel Adam would have needed to do with "Moonrise Over Hernandez" -- where he 
burned the (light) sky practically black in his (anlaogue) enlarger. Were he to do the 
same in Photoshop today in 8 bit, then yes, one MIGHT see enhanced noise and 
posterization -- however, much of this "might" is determined by what you are 
attempting to do and HOW you go about doing it. It is NOT TRUE AT ALL that if you 
perform extreme manipulations in 8 bits, then you are destined for posterization and 
enhanced noise. Again, it depends more on the user, not the technology. For 
example, actual "manual" Photoshop burning and dodging in 8bits gives perfect 
gradations, devoid of any banding. No advantage at all doing burning/dodging in 
16bits

So the sum of this is this:

- if you are trying to obtain an optimal digitization of a negative using modern 
scanning equipment, and your goal is to print this optimized image file as is, then 
there is no advantage to capturing, storing, printing in 16 bits. In oher words, for the 
vast majority of images (and users), 8 bits together with an optimal scan is more than 
adequate, in spite of all the theorists arguments to the contrary

- however, if your goal is to manipulate -- to an extreme degree -- an image way 
beyond its optimal "zone", then capturing and manipluating in 16 bit may have some 
advantages. 

- As others have noted, printing in 16 bits is a total waste.

Michael Sullivan
author of "Make Your Scanner a Great Design & Production Tool" published waaay 
back in 1994, now out of print

P.S. assuming someone has unlimited memory & harddisk space then go ahead, scan 
away at 16 bits -- at least there is no harm! However, my own experience with most 
users is that they do in fact have limited memory and harddisk space. For these 
people, I would instead recommend to them to learn how to do GREAT scans and save 
the files in 8bit

P.P.S in my experience, a lot of the 16bit vs 8bit argument involves a perverse form of 
bragging -- those with the horsepower (and latest tools) tend to brag about it. We've 
all heard a version of this before: "my car can blow the doors off of your car" kind of 
thing. Tedious. Boring.   In the end, RESULTS is all that counts, not HOW you did it.