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Author Topic: B/W color space?  (Read 5829 times)

teddillard

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B/W color space?
« on: December 22, 2008, 07:48:02 AM »

On another thread Andrew mentioned sending a grayscale file to the printer in AdobeRGB.  This got me to thinking...

Can you elaborate on this?  It seems to make sense, especially since in my experience the Epson printers like working with a file coming from Adobe better than anything else, but it raises some questions about how do edit and where to switch.  

Assuming I'm shooting RAW files and processing in Camera RAW, and using the HSL/Grayscale tab to convert to B/W, and printing to, say, an Epson 3800, are you suggesting that it's better to do all your edits in the grayscale space, and then convert to AdobeRGB as a last step?  ..or convert to Adobe immediately and then make your edits?

Is there a discernible difference in the output?  

And, as long as I'm going there, is there a practical difference between the grayscale working spaces?  

Are there any links you can point me to on this, to save yourself the tappin on the keyboard?  

Thanks...

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Ted Dillard

Jonathan Wienke

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B/W color space?
« Reply #1 on: December 22, 2008, 10:37:56 AM »

Since a grayscale file converted to RGB is going to have equal R, G, and B values, the gamut of the color space doesn't really matter. But the gamma curve of the color space will to some degree; if the source and destination spaces don't have the same gamma, then the equivalent of a curve adjustment will be done on the image data to convert from the source gamma to the destination gamma. But if they are the same, then the grayscales can simply be duplicated to make the R, G, and B channel values. If your grayscale file is gamma 2.2, use Adobe RGB, but if your grayscale file is gamma 1.8, use ProPhoto.

As to which grayscale gamma is best, 1.8 is closer to the tone response curve of printers, so gamma 1.8 images need less munging to be converted to the printer color space than gamma 2.2. Gamma 2.2 is closer to the native response of monitors, so I recommend using Gray Gamma 1.8 and ProPhoto as editing spaces and default color spaces for print files, and Gray Gamma 2.2 and sRGB for web and monitor-display-only files, especially singe most of these files are JPEGs and 8-bit-only.

digitaldog

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B/W color space?
« Reply #2 on: December 22, 2008, 10:51:11 AM »

Depends on what you're trying to accomplish. The send an Adobe RGB (1998) doc trick is simply to pass over a bug printing to the Epson using Advanced B&W under Leopard with CS4. Who's bug it is, is still being debated. If you print in a color space other than Adobe RGB (1998) using Let Photoshop Manage color, the print data never seems to make it to the printer. The ABW driver expects Adobe RGB (1998). If you were sending a toned doc, you'd use an actual output profile (NOT ABW) and you could and would select the color paper profile.
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teddillard

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B/W color space?
« Reply #3 on: December 22, 2008, 05:06:34 PM »

Quote from: digitaldog
The send an Adobe RGB (1998) doc trick is simply to pass over a bug printing to the Epson using Advanced B&W under Leopard with CS4.

ahh.  got it.
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Ted Dillard

Schewe

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B/W color space?
« Reply #4 on: December 22, 2008, 06:03:47 PM »

Quote from: digitaldog
The send an Adobe RGB (1998) doc trick is simply to pass over a bug printing to the Epson using Advanced B&W under Leopard with CS4. Who's bug it is, is still being debated.

Don't kid yourself Andrew, it's an Epson problem...the ABW Mode of the driver is color management stooopid and has been designed for Adobe RGB. So, if you send it ANYTHING other than gamma 2.2 (even sRGB is a tweaked gamma and isn't optimal) the driver thinks it's in Adobe RGB...the changes made to the print pipeline in CS4 and Lightroom 2.x is what made this stand out like a sore thumb...that's why the intentional double-color management trick works...it's taking whatever color space the image is in and converting it to Adobe RGB prior to sending it to the pipeline. Yes, there ARE some other gremlins at work–most notably Apple's friggin' ColorSync that seems to REFUSE to just send the friggin' data without doing some sort of "Generic RGB" conversion as a way of making itself part of the pipeline...personally, I would like to see Steve Jobs try to make a friggin' print and see the hoops we all have to jump through just to get this stuff to work. On this point, Windows seems to actually do less bad things than ColorSync...(but even on Windows, the ABW Mode is expecting Adobe RGB).
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teddillard

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B/W color space?
« Reply #5 on: December 23, 2008, 07:00:59 AM »

Quote from: Schewe
Don't kid yourself Andrew, it's an Epson problem...the ABW Mode of the driver is color management stooopid and has been designed for Adobe RGB. So, if you send it ANYTHING other than gamma 2.2 (even sRGB is a tweaked gamma and isn't optimal) the driver thinks it's in Adobe RGB...the changes made to the print pipeline in CS4 and Lightroom 2.x is what made this stand out like a sore thumb...that's why the intentional double-color management trick works...it's taking whatever color space the image is in and converting it to Adobe RGB prior to sending it to the pipeline. Yes, there ARE some other gremlins at work–most notably Apple's friggin' ColorSync that seems to REFUSE to just send the friggin' data without doing some sort of "Generic RGB" conversion as a way of making itself part of the pipeline...personally, I would like to see Steve Jobs try to make a friggin' print and see the hoops we all have to jump through just to get this stuff to work. On this point, Windows seems to actually do less bad things than ColorSync...(but even on Windows, the ABW Mode is expecting Adobe RGB).

woah.  

a 3 - "friggin" post.  

(fwiw, correct spelling and usage is "frikkin", according to my editor...)
« Last Edit: December 23, 2008, 07:01:40 AM by teddillard »
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Ted Dillard

Eric Myrvaagnes

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B/W color space?
« Reply #6 on: December 23, 2008, 08:56:23 AM »

Quote from: teddillard
(fwiw, correct spelling and usage is "frikkin", according to my editor...)
Sorry to quibble, Ted, but I'm with Schewe on this. I suspect there are local variants. Where I live, it's always "friggin". The "frikkin" looks to me like a Finnish version.  
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-Eric Myrvaagnes

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teddillard

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B/W color space?
« Reply #7 on: December 23, 2008, 09:10:24 AM »

Quote from: EricM
Sorry to quibble, Ted, but I'm with Schewe on this. I suspect there are local variants. Where I live, it's always "friggin". The "frikkin" looks to me like a Finnish version.  

dammit.  wrong again.

(not even spelled right.  she's gonna HEAR about this...)
« Last Edit: December 23, 2008, 09:12:33 AM by teddillard »
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Ted Dillard

Tklimek

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B/W color space?
« Reply #8 on: December 23, 2008, 12:15:06 PM »

Plus......

Jeff is located in Chicago (some of the time...  ;-) )......and we have words like:

Fronchroom = front room
Grachkey = garage key
Da Bears = The Chicago Bears football team

;-)

Holiday cheers....


Todd "In Chicago"

Quote from: teddillard
dammit.  wrong again.

(not even spelled right.  she's gonna HEAR about this...)
« Last Edit: December 23, 2008, 12:15:55 PM by Tklimek »
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teddillard

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B/W color space?
« Reply #9 on: December 23, 2008, 02:43:19 PM »

Quote from: Tklimek
Plus......

Jeff is located in Chicago (some of the time...  ;-) )......and we have words like:

Fronchroom = front room
Grachkey = garage key
Da Bears = The Chicago Bears football team

;-)

Holiday cheers....


Todd "In Chicago"

go cubs

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Ted Dillard

Schewe

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B/W color space?
« Reply #10 on: December 24, 2008, 12:13:57 AM »

Quote from: teddillard
go cubs


The Cubs, Bears, White Sox, Blackhawks and Bulls all suck eggs...there used to be great teams here in Chicago, now? Not so much...
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teddillard

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B/W color space?
« Reply #11 on: December 24, 2008, 05:24:17 AM »

Quote from: Schewe
The Cubs, Bears, White Sox, Blackhawks and Bulls all suck eggs...there used to be great teams here in Chicago, now? Not so much...

come on, the Cubbies?  FRIKKIN EXCELLENT!  

("...for when the little bears from the windy city to the north take the flag, the apocalypse is nigh." )



Have a great holiday, guys!
« Last Edit: December 24, 2008, 05:25:44 AM by teddillard »
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Ted Dillard

Tklimek

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B/W color space?
« Reply #12 on: December 24, 2008, 02:05:00 PM »

Professor Schewe......

Winning records are highly overrated.  ;-)

At least we still have the most awesome places to drink and eat!!

Todd in Chicago

Quote from: Schewe
The Cubs, Bears, White Sox, Blackhawks and Bulls all suck eggs...there used to be great teams here in Chicago, now? Not so much...
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