Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "joshhackney"
<joshhackney@g...> wrote:
...

I have thoughts on some of this, but not allof your concerns...

>...My real curiosity is that for those of us shooting digital, that
start out in an 
> RGB space, is it useful to convert to a gray space after our color
to b&w conversion, and 
> before continuing the rest of our edits in PS?  Are there any
downsides to staying in RGB?  
> Possible tints introduced, file size . . . something else?  I only
ask because my current 
> workflow includes Photokit Sharpener, which requires an RGB working
space.  

Then you must stay in RGB for that step, and that is the downside to
an earlier conversion. If not for your use of that particular filter,
I don't see any reason to stay in RGB.

> 
> Another question I have is why greygamma 2.2, and not greygamma 1.8?

There are any number of Gray spaces you could convert to for any
number of reasons. I tend to prefer keeping files in a commonly used
space so in the future the files can be repurposed. If it is converted
and archived in a space more related to a particulare output system,
it may become obsolete and less relevant for future printing. If you
are printing with a color managed system and will be converting to
print anyway, I think the choice matters less.
But the real issue is this-  Popular color spaces tend to be gamma
2.2, so your conversion to a gray 2.2 space will be less "lossy", and
2.2 is a common space out there in the world. So since you are likely
to have more than one conversion in your process (RGB-gray-output) it
makes sense to have at least one of them be as lossless as possible.
ProPhoto is gamma 1.8, so there could be an arguement for going to 1.8
gamma gray.
Keep in mind they will all display the same.

> When I bought 
> my first set of piezotones for a 1280, the documentation from Cone
said to use GG1.8.
> 

Jon likes 1.8 spaces. For years he's recommended using ColorMatch for
RGB, it's 1.8. He has fairly elaborate and rational reasons for this
involving issues besides gamma alone. One of the most educational
exchanges on a list was an arguement that lasted for days and days
between Jon and David Tobie about this issue. Things like that don't
happen on lists any more... I believe he is less dogmatic about it
these days. We've all evolved away from the "1.8 for Macs" thing.
Anyway, so if he uses a 1.8 RGB space, you can see why he would favor
a 1.8 gray space. He knows it works down the line with their profiles
because of his experience at their shop and therefore has specific
setting recommendations. Color management is so easily messed up that
helping poeple with product settings needs to be clear as a bell.
I asked him once, since his profiles were a color managed conversion,
if theoretically other spaces would convert to his profiles without
problems and he agreed it would probably work.

Anyway, if this is of any help, my thinking is to convert from RGB to
a commonly used gray space that has the same gamma as the RGB space
and archive, then convert when printing on the fly with the output
profile. I see no reason not to leave RGB as soon as possible, except
for your filter dilemma.

Hope that helps some.
Tyler