it isn't just US colleagues... trust me. I work in Australia and the US web coated SWOP v2 appears to be the default installed into the suite.
the more savvy out there are aware of this and change this once the software is installed via bridge... but i'm amazed how many people don't.
before continuing, have you asked your printers for their recommendations?
changing the CMYK profile from US to FOGRA will change the way they output. to demonstrate this more dramatically, take a FOGRA picture that you are comfortable with, convert it using the edit/convert to profile to US SNAP profile (for the purposes of this test) plus whichever options you would use in the conversion options and then SAVE AS the same name but with SNAP at the end of it. now place the two CMYK pics into indesign and then turn the overprint preview on... and see the difference.
ultimately, it depends on how the pictures are meant output at the time of print. if the US colleagues are happy with the colour they are getting from the US profile, i'd leave it alone and use the US profile.
it depends on the importance of colour in the artwork too - is the OP producing facsimiles of originals for provenance in museum catalogues, or trying to maintain a general overall colour consistency? can really go over the top dissecting this topic, but if this is to maintain a general overall colour consistency, i'd leave the US profiles alone if the US colleagues are satisfied with their results.
It certainly buys you absolutely nothing to convert the CMYK SWOP images to RGB of any type. The “damage” has already been done. You have already lost device independence and significant gamut. My recommendation is to leave the images as-is with their SWOP CMYK profiles intact, export PDF from InDesign maintaining all profiles, and let the RIP or other prepress software deal with the conversion of SWOP to Fogra39. The 4-3-4 conversion that would be done by Photoshop in such a conversion may not be as good as one done at your RIP with what is known as device link profiles.
Thanks guys, that was helpful.
I will ask some of our regular printers if they know what's best for both of us.
@ Cdflash - Fyi the images are mainly product shots en environmentals of electronic products. So the product shots are meant to have a similar look & feel to them. So I assume it's done for consistency yeah. Our photographer delivers all final images in Adobe RGB though, so we already have a big difference in those.
I always set the CS colour settings in Bridge for all our workstations, so anybody opening 'us-images' is getting a 'warning'.
@Dov - We would convert to Adobe RGB in case on any 'significant' retouching. For example implementing product renders of adding gradients, masks etc.
So you guys suggest to leave the 'us-images' untouched, import them where needed in InDesign and let the 'Export to pdf...' with the Fogra39 profile settings do the conversion.What you're saying is that the 4-3-4 (don' fully understand though) conversion of Photoshop is less good than a conversion done InDesign Export?
Thing is we do provide third parties with our images sometime and we're not sure about their expertise. So I'd rather have all images send out being in as few colour profiles as possible. Also we use some images for Newspaper print, so we have to convert those anyways to a different profile.
I guess I could go back to the US colleagues and ask if they want to keep and share the original RGB images (if available from the start) with us.
We're at the verge of changing our image server structure (established 10 years ago) and I'm trying to structurise the workflow. Don't want to make decisions now, that'll later will appear inefficient or flawed.
Again thanks for your time and knowledge.
To keep this simple, if you could get your images as the original RGB images, tagged in whatever color space they were originally shot (professional DSLR cameras typically default to either sRGB or Adobe RGB, although RAW images have no color space until processed in Camera Raw), you would have the most flexibility to edit, repurpose, etc. your images regardless of the final print conditions.
Some photographers and/or stock image vendors provide images as CMYK because they have been browbeaten by Luddite printers into that mode of behaviour (i.e., automatically converting everything into a specific CMYK because somehow RGB is evil).
What you're saying is that the 4-3-4 (don' fully understand though) conversion of Photoshop is less good than a conversion done InDesign Export?
The conversion on export (if you allow it to happen) would be directly from SWOP to Fogra and on press you might see some diffences if the source CMYK file had a lot of fully saturated CMYK colors (i.e. 100% cyan, magenta, or yellow)
It's easy enough to test in Photoshop. Take a SWOP CMYK image with a full gamut, duplicate it and use Convert to Profile with the destination set to Fogra. On the original, convert to AdobeRGB and then again to FograCMYK. You can then layer the two images and set color samplers with the eye dropper tool and see the changes in the info panel when you turn the visibility of the top layer on and off.
If the color is inside the gamut of all 3 spaces it won't change. There are CMYK colors that are outside of AdobeRGB and they would separate differently. 100% cyan gets clipped more on the RGB conversion, so I got 90|0|0|0 vs. 94|0|2|0.