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Danny W
09-19-2013, 08:51 AM
Hi.

Having used PDF/X-1a for all my output PDFs for years, doing the flattening and conversion when I create the PDFs, I thought it was time to update my workflow to PDF/X-4, and let the RIPs do the conversion. It seemed to work fine until I noticed that in one particular image, a lot of the darker detail, which had been visible in prints from the old PDF/X-1a workflow, was disappearing and printing as black.

So I tried a test sheet that I had, with few RGB images, all tagged with Adobe RGB, to test the difference between converting to CMYK when creating the PDF from InDesign, and having the RIP do it. I noticed that detail in dark areas and out of-gamut red areas that was visible if I did the conversion upon export, disappeared when the RIP did the conversion.

I put together another test sheet (see image) with the original problem image and some RGB patches to see where the detail 'dropped off' using the different conversion methods. The Adobe CMM definitely seems do a better conversion of very dark or out-of-gamut colours. As far as I can tell, the colour settings in both the Fiery and my Adobe software are identical (see screenshots below), so I'd expect both methods to yield an almost identical conversion.

Might there be another Fiery setting I'm missing? It would be a pity if the Adobe CMM did prove better or significantly different to the Fiery CMM, as I'd prefer the conversion was done by the RIP.

I should add that my files are assigned the FOGRA39 profile as Output Intent, and I use the same profile as CMYK Source/Simulation in the Fiery, but I see the same problems/differences when assigning and converting to the built-in Fiery output profiles and setting CMYK Source to None. We don't have Color Profiler Suite to create custom profiles, but we do calibrate with the ES-1000.


Konica Minolta bizhub PRO C5501
IC-408 Embedded Controller
Fiery System 8 Release 2

http://s21.postimg.org/7p38di3dz/indesign_colour_settings.jpg

http://s9.postimg.org/okvp4laxr/fiery_colour_settings.jpg

http://s15.postimg.org/6i2heeqej/RGB_Conversion_Test.jpg

oxident
09-19-2013, 11:16 PM
Interesting investigation. I have the same problems, although I do have a custom output profile.

Do you have access to the ImageViewer?

Justin_dB
09-20-2013, 04:17 PM
Hi - I have some additional details to add for thought.

Fiery System 11 is required for PDF/X-4 compliance. That being said, the Sys8Rel2, System 9 and System 10 Fiery are generally very good with PDF/X-3 complaint files, and handle transparency if Composite Overprint is enabled.

Thank you
Justin

Danny W
11-06-2013, 07:11 AM
Hi again, and thanks for the responses. Sorry for the huge delay in my response - recently the machines have been too busy for me to test!

I do have the Image Viewer installed as part of the Fiery software, but unless I'm mistaken, I'd need the full Graphic Arts Package license to use it (if it even works with System 8 Release 2). It's unfortunate, because I'd really like the ability to check the final CMYK numbers.

I've tried the same test file again, but using PDF/X-3 instead. Intriguingly, X-3 yields different results than X-4. The relationship between the files converted to CMYK by Adobe and the ones converted by the Fiery is roughly the same for both PDF versions (dark greys filling in etc on the Fiery's conversion), but the colours are slightly different. Hope you can follow this!

For now, I've reluctantly made it policy to convert to CMYK when I export the PDFs for output, as Adobe's conversion seems to yield better results. But it would be great if there was a setting I've missed in the either Fiery or my PDF export settings that would make this unnecessary. Any more ideas would be greatly appreciated.

ColorQA_Victor
11-06-2013, 03:26 PM
Hi Danny,

I have a couple of questions:

1) What is the source color space of the test image you are importing into your InDesign work space?
2) When you generated your PDF/X-3 compliant PDF, what was your Output > Color settings?

As for Image Viewer access, yes, the server needs the Fiery Graphic Arts Package, Premium Edition license. This package is not available for embedded servers.

If possible, could you send us the PDFs you are using for this test? We would like to examine them in hopes we can help you find the best solution for you workflow.

Thank you,
victor

ColorQA_Victor
11-06-2013, 03:41 PM
Hi Danny,

I have a couple of questions:

1) What is the source color space of the test image you are importing into your InDesign work space?
2) When you generate your PDF/X-3 compliant PDF, what is your Output > Color settings?

As for Image Viewer, yes, the server needs the Fiery Graphic Arts Package, Premium Edition license. This package is not available for embedded servers.

If possible, could you send us the PDFs you are using for this test? We would like to examine them in hopes we can help you find the best solution for you workflow.

Thank you,
victor

Danny W
11-11-2013, 06:51 AM
The image's source space is Adobe RGB, my usual working space. That is also the RGB profile assigned to the InDesign document.

The Colour settings for the PDF where Adobe does the conversion to CMYK:

Colour Conversion: Convert to Destination
Destination: Document CMYK - Coated FOGRA39 (ISO 12647-2:2004)
Profile Inclusion Policy: Include Destination Profile (this is greyed out)

The Colour settings for the PDF where the Fiery does the conversion to CMYK:

Colour Conversion: No Colour Conversion
Destination: N/A
Profile Inclusion Policy: Include All RGB and Tagged Source CMYK Profiles (this is greyed out)

I've emailed you the 4 files (PDF X-3 and X-4, CMYK and RGB).

Thanks again.

Danny W
11-11-2013, 06:55 AM
Also worth mentioning is that I'd rather not move to PDF/X-3 and the associated flattening if I can avoid it. I'm sure the marketing literature for the RIP says it can handle PDF versions that preserve transparency.

adam1991
11-11-2013, 12:22 PM
Well, the real issue is how the RIP can handle transparent effects from modern versions of Adobe CS and Quark.

Modern versions of the software can build documents in ways that weren't available before. So, it's possible to create a document structure that the RIP doesn't know about and will choke on.

Lou_P
11-11-2013, 02:07 PM
Looking at your workflow, today you are telling the adobe app to convert everything to FOGRA39L.

Mimimally to get a result close to ISO 2 / FOGRA 39L you need to set the CMYK source profile on the Fiery to ISOv2/FOGRA39L. Se CMYK processing to use Full (output) GCR.

This is the only way to get the CMYK to be correct since your Fiery is not a conventional FOGRA press.

To see what the RIP does you need to set "Let Printer Manage Colors", I think you know that since thats how you turn over the CM from Adobe to Fiery.

In this case for your RGBs, which the adobe app was converting them to FOGRA for you, set the option in Fiery Color to 'separate RGB/LAB to CMYK source". Most likely the adobe app is using Relative Colorimetric for the RGB to FOGRA conversion so you need to set that as the RGB rendering intent - or choose Photographic on Fiery if you were using Perceptual conversion for RGB when letting the adobe app convert the colors

A better result might occur if you leave this off and Fiery will convert directly to the output profile.

In any case do not expect what you were getting when you had adobe making FOGRA data then sending it to a RIP with color management off. If you love what you were getting I'm afraid all you can do it keep up the old workflow, and keep calibrating the Fiery since even with Bypass Conversion set the calibration is keeping your color consistent.

After you get this working for a simple page with RGB and CMYK images then you can come back to trying some PDF/X-4's with transparency and other challenges.

~Lou

Danny W
11-12-2013, 02:56 AM
Well, the real issue is how the RIP can handle transparent effects from modern versions of Adobe CS and Quark.

Modern versions of the software can build documents in ways that weren't available before. So, it's possible to create a document structure that the RIP doesn't know about and will choke on.
I would have thought it was the PDF version that mattered. If the RIP is claimed to be capable of processing PDF 1.6, and I specify PDF 1.6 when I export from InDesign, then there shouldn't be problems unless InDesign isn't adhering the specified PDF version.

Anyway, I haven't had any trouble with transparency, unless spot colours are involved (and if I've created the artwork or preflighted customer artwork, they aren't).

Danny W
11-12-2013, 03:08 AM
Lou, I think I've done pretty much everything you suggest (see screenshots in my first post). I definitely didn't have 'adobe making FOGRA data then sending it to a RIP with color management off'. And apologies if I'm mistaken, but isn't 'Let Printer Manage Colors' purely a printer driver option? This is all exported PDFs, no printer driver involved.