RGB or CMYK in print?

[dleather]

It would be an interesting exercise to take a RAW image straight out of the camera and have some of the prepress folks on this forum do their massaging of the image as if it was a live job and compare the differences in final work. I'd be happy to supply one if there is interest.

best, gordon p

That would be interesting. Our prepress provider usually gets the Raw image, the .plist file, and a low res JPG from the photographer as guidance for focus, white balance, color settings etc. (Our end result is color matched to specific fabric swatches, so what the camera captures always gets changed anyway...) A quick screen shot, or low res JPG of the "desired" result could help here too.

 

[Stephen Marsh]

dleather wrote:

> That would be interesting. Our prepress provider usually gets the Raw
> image, the .plist file, and a low res JPG from the photographer as
> guidance for focus, white balance, color settings etc.

Just curious, but what (Mac) raw converter are you using that imports
settings via a PLIST file? Adobe products usually use .xmp, so I am
presuming that you use another converter?

Stephen Marsh

 

[graficworx]

Printer profiles

Printer profiles

Everyone has had some great discussions on how to get the files, but it's equally as important to how you send the files to press. Any printer or press on the market uses CMYK natively. None use RGB, as RGB is a subtractive color profile (subtracts from black) and CMYK is additive color (adds to white). If you sent a press operator an RGB file they may reject it, or convert it. If they convert it themselves it will not look like how you saw it.

If you convert it to CMYK yourself and you have the correct color profiles for the output device it should look the same on almost all output devices from inkjet to offset press and everything in between. Of course there will be slight color variations that's unavoidable.

300 dpi at full size is usually accepted as the industry norm. That should be sufficient for any output, and is fine for offset press or laser output.

 

[gordo]

Count me in!

I would suggest that we all agree, or that Gordo stipulates a common colour space (say either sRGB or a specific ISO CMYK) and also a common resolution in pixels and a format such as JPEG (I guess it depends if the results will be viewed in a browswer, or say a PDF or PSD etc).

It would also help if Gordo gave some sort of "brief" to describe the intent of the rendering - or just give us all freedom to do what we wish without "customer creative direction".

Stephen Marsh

Dang, looks like I've got some work to do. Like think and take a photo. I'll do that tomorrow.

It probably should be some kind of product photo rather than something arsty.
Perhaps the RAW image should be prepared for the web (I'll spec the pixel dimension so that they can be displayed in a forum's post or somewhere else) so that'll be sRGB and for the CMYK it probably should be targeted for a "magazine ad" rather than a color space since, unlike prepress folks and color gurus, that's probably what the typical designer is thinking.
If that makes sense, I'll post the RAW image (15mb) and provide a download link tomorrow.

best, gordon p

 

[Lukas Engqvist]

hmm sRGB, I'm seeing the weakest link

hmm sRGB, I'm seeing the weakest link

Just to have it compared on the web means we all will go to sRGB, and that will be the weakest link. Whatever extra you can get out of camera Raw to make it a superduper print, will be lost when you convert that to sRGB to display for "comparison" Next we'll be comparing racecars stats in the parking lot of the local mall?

 

[gordo]

Just to have it compared on the web means we all will go to sRGB, and that will be the weakest link. Whatever extra you can get out of camera Raw to make it a superduper print, will be lost when you convert that to sRGB to display for "comparison" Next we'll be comparing racecars stats in the parkinglot of the local mall?

Hmmm, maybe I'm wrong, but sRGB should allow people to compare the images on the web - but sRGB doesn't have to be used for the CMYK version.

Or, what would you suggest to do?

gordon p

 

[mattbeals]

Here's another kooky idea...

Gordon selects an image, maybe some sort of "standard" RGB test image we're all familiar with and puts it on a test form with an output intent (a la PDF/X-3) of say SWOP2006 3v2 or FOGRA39. I don't know, some standard profile we all have. Then we use our respective RIP's to convert the RGB data in the PDF/X-3 to CMYK.

That may be more to the point of where the conversation should be going. As I said, we have some sort of "standardized", at least we agree on what image and color space, image that an advertiser may use in multiple ads going to different print providers. Send it as a PDF/X-3 and see what RIPs would do with the RGB to CMYK conversion. This comes close to the idea of a "digital master" that print providers need to convert for printing.

Would this not address Sannysmith's original questions of:

Hope makes sense as I really have no idea how print publication works. The photographs would go in various print magazines,brochures, etc.

1) Since I am new to the world of print publication I wanted to know if a RGB at 300dpi or CMYK at 300dpi photograph is advisable.

2) Also when giving instructions to a professional photographer what all should I mention that I need a high res tiff file. Is that the best format to use for print?

The RAW exercise is definitely an interesting one but may be going off track. I think a few people have made a valid point that RGB is more likely to be the "original" color space provided to the advertiser. It's a reasonable baseline assumption for many real world situations. The advertiser/content provider composes a page and submits it for production. Let's all assume it's SWOP 2006 3v2 for schlitz and giggles. What does Apogee do with an X-3? What does Prinergy, RAMPage, Harlequin, etc do? We all can get a color managed bitmap or PDF out of our workflows that reflects the conversion process. We can then collect all the results and and make some sort of comparative analysis. This might actually provide real world, meaningful results to not only ourselves but the rest of the print community. The ultimate question may be "can a late binding color managed workflow provide acceptable results?"

 

[meddington]

The RAW exercise is definitely an interesting one but may be going off track. I think a few people have made a valid point that RGB is more likely to be the "original" color space provided to the advertiser. It's a reasonable baseline assumption for many real world situations. The advertiser/content provider composes a page and submits it for production. Let's all assume it's SWOP 2006 3v2 for schlitz and giggles. What does Apogee do with an X-3? What does Prinergy, RAMPage, Harlequin, etc do? We all can get a color managed bitmap or PDF out of our workflows that reflects the conversion process. We can then collect all the results and and make some sort of comparative analysis. This might actually provide real world, meaningful results to not only ourselves but the rest of the print community. The ultimate question may be "can a late binding color managed workflow provide acceptable results?"

This would be an interesting endevour (actually wondering if there has aleady been something similar formally done), but for different reasons than the test gordo suggested. In comparing RAW image processing, you're really comparing how a live operator is interpreting how the image should look...a subjective analysis of how the scene should be interpreted.
The test you suggested is essentially comparing how color management is applied via processing a PDFx-3. This would require a much more objective analysis as the differences should be limited to conversion settings at the rip, CMM choice, rendering intent, gamut mapping characteristics of the profile (which has nothing to do with the Workflow itself), etc. You'd likely want a much more objective analysis of the results...Colorimetric analysis of it8.7/4 chart for example. The altona suite would be a decent choice for this type of test. But because the differences in gamut mapping are due to the icc profile and the software that generated it, the results you get might not be conclusive ,unless perhaps by mandating a specific icc profile (rather than characterization data), rendering and CMM. Even then, if someone chooses to use their own profile generated from the charsterization data, the results may vary, but this could not be considered truly deviant.
Of course this only tests the suggested PDFX-3, which is only one option., and debatable how "real world" this actually is. How many printers out there actually receive PDFx-3 files, compared to say x1-a, or other flavor?

 

[John Clifford]

Hi John,
PDF/X-1a can indeed contain color profile information - and often does - and as a PDF/X-1a PDF file requires an output intent (which is itself a ICC Color Profile) - well...

Micheal,

Great to cross swords with you again. I believe that the PDF/X-1a spec disallows any ICC profiles from being attached to a file. This was the major difference between X-1a and X-3 (I remember Stefan Jaeggi at Seybold's railing about we backward North American's with our unwillingness to accept color management -- or something like that). Thus my comment. X-1a requires conversion to CMYK and does allow for output intent, but not color management.

From the PDF/X-1a standards: PDF/X-1a is designed to provide the most robust and, to some extent, least flexible delivery of PDF content data. It requires that the color of all objects be expressed in CMYK or spot colors, prepared for the intended printing conditions. Elements in RGB or Lab color spaces OR TAGGED WITH ICC PROFILES ARE PROHIBITED. It also requires that all fonts used in the job be embedded in the supplied PDF file.

 

[mattbeals]

To me the output intent of a PDF/X-1a file expresses what color management has been done. That is, what color space the art has been converted to and simply communicates that to the recipient.

 

[meddington]

I believe that the PDF/X-1a spec disallows any ICC profiles from being attached to a file.

PDF x-1a does allow for the output intent (ICC profile) to be embedded within the PDF, but I think your saying that it doesn't allow for individual elements to be tagged, is that right? X-1a files with embedded profiles pass preflight in Acrobat with no errors.

 

[dleather]

dleather wrote:

Just curious, but what (Mac) raw converter are you using that imports
settings via a PLIST file? Adobe products usually use .xmp, so I am
presuming that you use another converter?

Our prepress vendor wrote the program they use. They won't tell me much about it since it's "proprietary", but the gist is that they develop using whichever 8 bits of the full 12 bit raw file that they chose, so each image has the darkest darks and the brightest whites, and the most vivid colors available to them.

 

[gordo]

[SNIP]
Would this not address Sannysmith's original questions of:

Hope makes sense as I really have no idea how print publication works. The photographs would go in various print magazines,brochures, etc.

1) Since I am new to the world of print publication I wanted to know if a RGB at 300dpi or CMYK at 300dpi photograph is advisable.

2) Also when giving instructions to a professional photographer what all should I mention that I need a high res tiff file. Is that the best format to use for print?
[SNIP]

To be blunt about it - NO. A profile or PDF format or RGB/CMYK mode choice is not the way to make up for a lack of knowledge/education ("I really have no idea how print publication works.")

If the OP wants to call himself and market himself as a designer then IMHO he has a professional obligation to himself and to his customers to learn his trade first.

best, gordon p

 

[Stephen Marsh]

Our prepress vendor wrote the program they use. They won't tell me much about it since it's "proprietary", but the gist is that they develop using whichever 8 bits of the full 12 bit raw file that they chose, so each image has the darkest darks and the brightest whites, and the most vivid colors available to them.

A custom raw converter...

Do they market this to the public (website?) - or is this an "in-house solution"?


Stephen Marsh

 

[gordo]

The RAW challenge

The RAW challenge

There was some interest in seeing how different prepress folks would handle an incoming RAW image file.
I thought I'd start with an artsy image after all. Later I'll provide a commercial one.

The background, this image is destined for a tourism web site promoting this rugged beach. It needs to be 1000 pixels wide and in sRGB color space. The original RAW image is 13mb and can be downloaded by clicking on this link:

http://rcpt.yousendit.com/806507006/2f4a6da1a387716e89f6808db9154f75

It will be available for download for 7 days.

If you send me your finished image as a .jpg at highest quality setting it should weigh in at about 1.2mb.
I'll then post all the finished images in one post to this forum for comparison.

Enjoy! gordon p

 

[Lukas Engqvist]

Sorry I stirred things up and then got on with my work, I just meant that the test would be difficult to get an objective answer judging conversions from RAW to CMYK when limiting to the web. Looking at CMYK we would be judging simulations.

I am still confused that there is so much x-3 talk, I thought PDFx-4 was the only real alternative to PDFx1a. PDFx-3 would need to be no transparent objects ever policy and that leads you up a dead end street imho.

For OP, I would say if you don't know what device and substrate you are outputting to how can you make it into CMYK? An ICC tagged RGB photo is best. If the photographer is experienced he can deal with the commonly out of print gamut colours, else you would like to leave it untouched till a prepress knowlageble person with a calibrated monitor can adapt it to the output intent (eg Euroscale Coated v2, at an appropriate Total Ink Limit). Talk to your print supplier and if you have a chance let them show you how they work. Let the person who you will hold responsible call the shots.

 

[gordo]

Sorry I stirred things up and then got on with my work, I just meant that the test would be difficult to get an objective answer judging conversions from RAW to CMYK when limiting to the web. Looking at CMYK we would be judging simulations.

I thought I'd start with the web only because that would show how prepress would process/interpret the RAW image. For the second image, which I'm working on now, I'll be asking for both web and CMYK from RAW.

best, gordon p

 

[CruzinCooler]

Keep it simple.

Keep it simple.

Most print shops will require a CMYK tif or eps file for commercial/publication print work without an ICC profile. Also they will need to produce a proof of that file for any future color corrections. Their proof should reflect the press it will be printing on and their prepress dept. will have an ICC in the RIP reflecting the press to be printed on.

 

[Stephen Marsh]

If you send me your finished image as a .jpg at highest quality setting it should weigh in at about 1.2mb.
I'll then post all the finished images in one post to this forum for comparison.

Enjoy! gordon p

Thanks Gordo, I will send you something tonight or tomorrow morning.

It will be interesting to see all the different takes on this image!

Do you wish a description of the edits, or will the picture speak for itself?


Stephen Marsh

 

[gordo]

Thanks Gordo, I will send you something tonight or tomorrow morning.
It will be interesting to see all the different takes on this image!
Do you wish a description of the edits, or will the picture speak for itself?

Stephen Marsh

Nope, let the picture speak for itself.

best gordon p