IF of interest and maybe for discussion.
I’ve placed this as an ACR feature request:http://www.adobeforums.com/webx?14@@.3bb6a85c.3bbc8060/357
The merits of Raw are well documented and have been broadly discussed. Compared to JPGs from in-camera conversion, Raw data can easily bear up to approx. 1-stop more of dynamic range. Raw processing allows to recover these highlights e.g. via the Exposure slider in ACR. Also, Raw features a better correction and ex post adjustment of White-balance via Temperature and Tint controls.
Further, Raw data can be processed and released into a large gamut such as ProPhoto RGB (pRGB), thus preserving a major part of scene-referred color saturation. Many of such saturated colors are already within the reach of today’s printer; others may require particular attention to avoid posterization.
Image details and sharpening are another aspect. In-camera sharpening is not known to be particularly advanced and therefore prone to amplify noise or to cause artifacts if overdone.
Now referring to JPGs from in-camera conversion, and in consideration of all limitations including tiny sRGB gamut, we have to admit that their “look” can be surprisingly good if not even preferred. Speaking for myself only and some experience with Canon gear, impression is that image rendition and color appearance with JPGs have much improved in the course of technological progress. Same may apply to other brands.
Many user seem to feel the same and often enough a generic Raw converter such as DPP is preferred to access said “look”, even at the cost of workflow speed and convenience vs ACR. It’s sometimes claimed that any of such “look” can be mimicked in ACR, however, I’d like to disagree with this. Even simple in-camera settings such as Contrast or Saturation are apparently following complex and different definitions than commonly known, and also single hues are shifted away from colorimetric accuracy to whatever camera engineers have identified as “pleasing”.
Further, it can be assumed that in-camera conversions feature a perceptual gamut compression, so there’s less channel clipping with saturated colors compared to a straight Raw -> pRGB –(RelCol)–> sRGB pathway.
Coming to the point:
Many of today’s cameras allow to capture Raw + JPG simultaneously.
ACR since version 4.x (iirc) allows to process Raw or JPG.
Wouldn’t it be possible to combine and blend both images at the level of linear-gamma ProPhoto RGB (1.0 pRGB) which ACR was reported to use as an intermediate working space ?
All controls which are applied before or during the conversion Raw -> 1.0 pRGB would still act on this transform only. While the JPG is converted to same 1.0 pRGB at 16 bpc, all controls which are applied after arrival in 1.0 pRGB would act on a blend of both images. This is of course just meant as rough description, hoping that Adobe engineers would get the gist while being much more familiar with ACR mechanics.
Basically I’ve tried what I suggest by doing such blends in Photoshop, then going back to ACR again. Results seem to confirm the idea and intention in principle i.e. to enhance JPGs by insertion of Raw data information, or the other way round, to enhance the ACR processing chain by inserting a touch of “JPG look” as conceived by camera manufacturers.
Finally it should be mentioned that the idea is not really new (see Link and White Paper), but maybe today’s RAW + JPEG combo could offer an up to date implementation with ACR.http://www.kodak.com/global/en/professiona...erit/erit.jhtml