Something went wrong with the link you posted. I'd be interested in reading the past discussion on the subject.
The way in which I manage this is to batch-convert a series of progressive exposures in ACR 7.1;
Select all of those files in Bridge and use Tools/Photoshop/Merge to HDR Pro and
Save as 32-bit.tif (floating);
Then open that Tiff in ACR 7.1 to refine the editing (making full use of the Adjustment Brushes);
Finally, I open the file directly from ACR into Photoshop CS6 as a ProPhoto RGB 16-bit Smart Object and finish the image.
This works beautifully and produces very smooth and wide DR images without those horrendous HDR grunge haloes.
While you could do part of this in LR 4.1 if you wished, you do need Photoshop CS6 for some of the steps.
Our design of ACR/LR is to render images for display or print. When starting with scene-referred images (e.g., raw), this means tone and color mapping the input linear light data (e.g., whether 12-bit integer or 32-bit float) to values suitable for reproduction (output-referred). Since the resulting is always intended to be output-referred, the resulting images are always stored using 8-bit or 16-bit values. We do not see any need to represent output-referred data using 32-bit values.
(ACR/LR is not intended to be a "pass-through" system that can, say, take 32-bit image data as input and also emit 32-bit image data at the end. It can be made to do so, though clumsily.)
Our design of ACR/LR is to render images for display or print. We do not see any need to represent output-referred data using 32-bit values.
Thanks for your reply Chan.
That is too bad, since you offer the use of ACR in PS and AE which are programms that allow further image processing aswell. It would be great to use advanced masking to bring back highlight or shadow detail in PS or AE just for certain areas since the capabilities of the adjustment brush are very limited compared to what those programms offer.
As stated in this thread: http://forums.adobe.com/message/5313077#5313077 I do indeed see a very important use for being able to export floating point files, once you export as tif file, your dynamic range is lost, this is very problematic when you have to create HDRI files and still benefit from ACR Undistortion and Camera Profile.