Caution: long, nerdy response
Your question caused me to go back and re-read some more from "Real
World Color Management" and specifically on Adobe RGB. The discussion
is from Chapter 10 titled Color Management Workflow and in a section
that discusses input, editing and output color spaces and the
distinction between what's called early and late binding.
In early binding the input, editing and output spaces are the same.
That's the case for sRGB as input and editing space when we know we're
going to a lab or other output process that wants only sRGB. The
process is simplified and mistakes are reduced such as the case of your
240 prints made to the wrong color space.
Adobe RGB is described as an editing space and designed to be used with
late binding... meaning that the image is converted to, edited and then
kept in the Adobe RGB space until such time as it's necessary to convert
to an output space for screen or print. The reason for this is that
Adobe RGB has a larger gamut. Not specifically discussed here but I
believe the reason it's called an editing space is that the larger color
gamut makes it less likely to lose color info to arithmetic
manipulations when we edit just as Moose suggests converting 8 bit
images to 16 bit during editing even though they're going out as 8 bit
in the end.
But nothing is ever completely simple. The discussion of Adobe RGB as a
device-independent RGB space says:
"One solution, embodied in Adobe Systems' applications but usable by
others, is to use a device-independent, gray-balanced, perceptually
uniform space such as Adobe RGB (1998) for editing. This approach has
proven sufficiently popular to spawn a plethora of editing spaces -
often named for their developers - and debating the merits of each is
decidedly outside the scope of this book. Instead, we'll simply say
that the main criterion in choosing an editing space is its gamut.
Bigger isn't necessarily better. The trade-off is between finding an
editing space that won't clip colors in either your capture or your
output, and finding an editing space that doesn't waste huge numbers of
bits describing colors that you can't capture, display, print, or in
some cases, even see. In practice, it's pretty much impossible to find
a space that contains all your colors but doesn't waste bits, so you
simply have to pick the best trade-off for your particular purposes."
Now a final point on sRGB for wedding and event photographers as
championed by Will Crockett (who is also a wedding photographer as well
as a stump speaker). No discussion of Crockett is complete without
saying that he is also a strong proponent of wedding photographers
shooting only in JPEG. As a matter of efficient and profitable work
flow (weddings involve hundreds or even thousands of images) the
photographer should make extreme efforts to get the exposure and white
balance correct within a small fraction such that adjustments to same
are not necessary and JPEG's contain all that's required for color
content and print. Whether this is doable or desirable is a separate
discussion but serves to illustrate the sRGB decision which is based
mostly on a simplified work flow through to a lab generated print. YMMV.
Chuck Norcutt
Jon Mitchell wrote:
> Hi All,
>
> Just to weigh in with my opinion (not based on anything but my own
> procedures - which seem to work for me).
>
> I shoot in Adobe RBG. Everything is processed in Adobe RGB, 16-bit,
> 300ppi. PSD files are saved as such. I then have a PS action set up to
> create a Hi-Res sRGB 8-bit JPEG from the finished PSD file (which I send
> off for printing if required), and yet another action set up to create a
> Lo-Res sRGB 8-bit JPEG - resized to 800 pixels on the longest side and
> 72ppi - which I then use for posting on the web, browsing on my
> computer, etc.
>
> As someone else here has posted, adobe RGB has a wider dynamic range or
> something like that. My logic is that it is better to work with that,
> and then convert to sRGB at the final stage. I must admit to having
> done zero comparative testing with this, so YMMV, etc....
>
> To add further to this - I consider it critical that if the printing lab
> you are sending the files to is going to work in sRGB then you must send
> them the files in sRGB. Never trust their "automated systems" to
> convert for you. I have discovered this when I sent 250 files off to
> get 6x4's of them all as proofs, only to discover that the files were in
> Adobe RGB. The prints came back looking wrong, to varying degrees
> depending on picture content. Generally, slightly milky with a slight
> green hue to the whites.
>
> In my case, I use PhotoBox and they clearly state that files should be
> sent in sRGB format (for prints up to silly-big-size at least). My
> stupid fault really, I knew it and didn't check the files I was sending.
>
> Hope this helps. It is only my opinion, and would welcome the thoughts
> of others more knowledgeable than I ;-)
>
> Regards,
>
> Jon
>
>
>
>
>
>
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