Thank you all for pointing me in the right direction and noting that DxO produces LINEAR DNG files.
I have researched this a little now and have found the following useful information:
, Jun 03, 2009; 01:09 p.m. "Late, late response for those who may find this thread in a search about linear DNG or DxO.
DxO Optics Pro is currently up to version 5.3.3. It can still produce linear DNGs which are most definitely readable by Lightroom/ACR. It is important to understand that these are not RAW files, and some information may not be carried over into the DNG. For instance, if Dxo clips highlights, the highlights will remain forever clipped in LR or any other digital editor. Clipped shadows, in contrast, are virtually completely recoverable, a disparity that I do not understand. On the other hand, DxO can do a superb job at highlight recovery, far superior to LR/ACR in my experience. So, the trick is to set DxO\'s "Exposure Compensation" control to "slight" so that it will automatically recover highlights. On some images, you may need to go to a stronger level to accomplish this, but the software is very good at pulling detail out extreme highlights.
So is it worth the effort to use Dxo as a prelude to LR/ACR rather than just processing directly in the latter? My answer is a very strong "yes." The RAW conversions from DxO are far superior to what I can get in LR, no matter how hard I try. I have done a great many comparisons, and believe me, the DxO processed images are much sharper, cleaner and more detailed, and they have a level of 3D modeling that I have not seen with any of the RAW processing programs that I have tried."
Also a lot of good info at http://www.barrypearson.co.uk/articles/dng/linear.htm
"When ACR handles a Linear DNG file, it doesn\'t demosaic raw image data, because there isn\'t any. Perhaps there once was, but this was done earlier, for example by DxO or by the DNG Converter.
"When ACR handles a Linear DNG file, all of the tabs, sliders, and drop-down boxes still work, and do the sort of things expected of them. It is a digital image processor without any demosaicing to do, yet it is still useful. It can be used to set the white balance, correct for chromatic abberation, reduce noise, sharpen, apply a curve, etc.
"If an image starts as a raw image from a digital camera
, to become Linear DNG it must be "converted", typically "demosaiced". This may be done in Adobe\'s DNG Converter
, or elsewhere, such as DxO
. But once this conversion has been done, it is committed - whatever product processes the Linear DNG can\'t exploit its own, potentially unique, conversion(s)."