@Marsu42: You trying to lossy compress with Adobe unprocessed Dual ISO? Why? I've read that lossy DNG compressed files no more Raw, it's demosaiced data. Demosaicing algorithm didn't expect to meet Dual ISO raw - this why artifacts, no?
My understanding that a dual_iso file should be the same as a vanilla raw after it's reconstructed by cr2hdr. Adobe supports these 16bit raw files in ACR (Lightroom, Photoshop, DNG Converter), and I see no reason why lossy compression shouldn't work as well - though of course you can never be sure with closed source software.
It's an important feature for Adobe apps - smart previews enable you to do faster and offline editing, and lossy dng is great for archival of less important shots w/o resorting to jpeg. Btw the "standard" preview in Lightroom is broken as well with the same artifacts, seems to use the same compression algorithm.
On the bitbucket bug tracker, dmilligan guesses that this might have to do with the non-standard black level dual_iso files. I cannot say and I'm unable to change cr2hdr to test this, but lossy dng *does* work fine with mini_mo files which also have a custom black level (but break dxo's raw converter).
I'm finding the dual ISO files a bit greener. 5D mark III 1.2.3 but build number doesn't matter because it's been all the way since I started using Dual ISO. Anyone notice this in the DNGs? WB is odd.
I'm on 6d/60d, and I consider wb "more than odd". I cannot verify the theory that dual_iso and vanilla should just look alike, just with dual_iso having cleaner shadows. My current method is to let Lightroom figure it out with the "auto" setting on import which works better than the current cr2hdr detection attempts for guessing auto wb. The "auto" setting also gives you a hint in which way to correct files with a fixed wb setting from the camera.
Having said that, hdr pictures somewhat do look a bit odd in the shadows anyway (esp. concerning green/magenta tint), so that might be one cause of confusion and bogus bug reports.
