I've made a number of ProPhoto to sRGB device links with collink using a range of different settings.
All of them create images with odd dark blobs appearing in saturated blues.
Here is a tiny section from a test image (8KB): <http://inside.rgb2cmyk.com/images/BstrdBlue.tif.zip> And this is the result I get when applying the device links: <http://inside.rgb2cmyk.com/images/BstrdBlue.jpg>Changing the quality and rendering intents will produce a more defined and lighter/darker black patch but I cannot get rid of it.
I haven't seen this happen when converting any other RGB working space to sRGB. Am I doing something wrong?
-- Martin Orpen Idea Digital Imaging Ltd