Am 19. Nov 2004 um 19:50 schrieb Peter Kleinheider: Thank you Peter for keeping this discussion going. One thought to max K = 100%: In terms of device independent / media neutral data handling and retouching in color spaces such as ECI-RGB or others, it seems contradictory to have in mind that certain output profiles have a specific max K setting, no matter which. To keep the workflow pure and straight, one could prefer to generate maximum dynamic range within device independent data. Device dependent settings and separation parameters belong completely into the output profile. Proposal here: max K to 98%. Nevertheless, I haven't had problems with max K of 100% with any decent separation from any image. I made print tests comparing 95, 98 and 100 percent side by side separated from the same image - there was no visual difference, rather slightly (very slight) better contrast with 100%K, no loss of details or something. Regards, Andre Schützenhofer _______________________________________________________________ a.schuetzenhofer(a)con-cept-pro.com · http://www.con-cept-pro.com

Hi Peter Yes I definitely agree with all of that. IMHO , although generally speaking there will be very little 255/255/255 in most photographic images , there are still many exceptions to this rule in certain areas of photography. For instance, we shoot a lot of Guinness on solid black backgrounds as per the clients brief. We have a test file that includes a number of 'challenging' images and a 'supersaturated' test bar . We've run this using the ECI profiles and relative rendering , and the saturated blue tends to move towards purple. We're using Gretag Macbeth Profilemaker 5. We've found that the sort of anomalies that occur in the saturated colours in the ECI profilers are the same that can occur when building a profile when use the extra chroma facility in our software . Building profiles without this produces a more accurate although somewhat less saturated blue. To put this in context , it's probably best to outline our companies profile and how we use the ECI profiles. Our core business is advertising photography ( everything from beer to superyachts, including model photography ) and post production ( everything from retouching and image manipulation to proofing and press targeted CMYK output). Because we have been shooting entirely digitally for the past six years , we've become heavily involved in the whole production process , and as a result ended up working on several standards and best practice committees. It's also lead to an extension of our business into consultancy and training on digital workflow for photographers, agencies, design groups and press houses. With all of our photography , we always engage our clients in dialogue about their preferred workflow. When any confusion arises on what flavour of CMYK is required , we will usually look to what proofing standards their pre-press / press house uses , and aim at that target. If that remains an unknown also , we will look to providing a generic CMYK file that is re-purposable in addition to a wide gamut RGB file. The the prior' one size fits all' CMYK space was the Euroscale coated V2 incorporated into Photoshop, and this was also the space originally chosen by the PPA in the UK. There is nnow however a distinct move to ISO standards , and we are encouraging our clients to go this way. The tremendous work done by the ECI is a great help here because we can direct them to the ECI site to read up on the research and methodology that supports this route , and download the relevant profiles to test and possibly use in their production workflow. If they choose to do so , then we would use the same profiles if requested. In our training and consultancy , we also recommend this route with the proviso that our clients fully understand the implications of doing so. For jobs where we are asked to provide images to ISO standards , without the specific ECI profiles being referred to , we would use one of our own profiles based on the FOGRA data , choosing or building a profile that best suits the type of imagery that we are supplying . For instance , for the yacht interiors we use a profile that we optimise to produce the best detail/colour combination into the shadow areas , but will use a profile with a completely different black generation for neutral / black and white pictures that are being printed four colour. One of the great advantages for us of the ISO standards is in the area of proofing. A non proprietary target is a great advantage here , and we run our proofing device to suit ( BTW , the ISO certification appears fairly wide in it's tolerances .....we prefer to run an 'in house' tighter specification that allows for less variance in output ). Regards , Bob Marchant. Colour Therapy London UK