If you open a RAW file throuh ACR as a object the smart object layer object is the RAW file. You can the create a new independent Smart object layer using that layer and Photoshop menu Layer>Smart Objects>New Smart Object via Copy. You can then open that new Smart object layer object it will open in ACR. Change the ACR setting and Click OK in ACR to commit the changes. You will then have two Raw conversion layers with different rendered pixels. You can composite these layers together using Photoshop features and tools.
Thank you very much for your help. I am surprised that by cmd J the functionality is completely different. Now I know better.
Best Regards and Happy Eastert
This used to be standard procedure with raw processing - until Process Version 2012 in ACR/Lightroom, with vastly improved dynamic range capabilities. This was available from ACR 7 in CS6 and onwards.
In short, the stacked smart objects are rarely necessary nowadays. The Highlights and Shadows sliders, properly used, and in combination with the other sliders, can usually bring out everything that is there in the file.
This will most of the time look better and more natural than anything you can achieve with masking, unless you put an awful lot of work into the mask.
I feel you still need to work at it with ACR using local adjustments which lets you have multiple ACR adjustment for a single RAW file. This feature is also using masking within ACR. So Yes you can do a lot more with current ACR versions then the versions of ACR used in Photoshop versions prior to CS6. The main reason I keep upgrading prior Photoshop versions was for the improvement being made to ACR.
Adobe crippled new ACR feature in CS6 though you can use ACR 9.1.1 in CS6. CS6 is only able to use its new Camera RAW format support not the new features added to ACR after ACR 7 I believe new feature adden in ACR 8 and 9 can not be used in CS6..
I feel you still need to work at it with ACR using local adjustments which lets you have multiple ACR adjustment for a single RAW file. This feature is also using masking within ACR.
I'll add a 'me too' to that. Local adjustments in ACR are a huge advantage, and that is especially so with 32 bit HDR files, but by heck it is hard on system resources. With four or more local adjustments to a 32 bit file, my system is showing noticeable lag. With half a dozen I am waiting two or three seconds to get control back after each operation.
Well, FWIW, I didn't say you couldn't use local adjustments in addition.
My point was that the shadow and highlight information is generally accessible in a single instance of the file. That wasn't always the case with PV 2010.
That said, the best results are usually achieved by pushing global adjustments as far as they will go first, and only then move to local adjustments if necessary.
But the information you have in the raw file are much deeper and realer than those you can get out of a tif or jpg.
Well, yes and no. The problem with a raw file is that it doesn't look like the original scene at all. It's just a very flat, dull and dark grayscale image.
To get a useful/realistic image out of it, you have to throw out a lot of information. There's no way to avoid it. As long as you still work with the raw file, you can choose what to leave in and what to leave out. But something has to go.
If you insist on cramming it all in that might be possible, but the resulting image wouldn't be much to look at. It would have no contrast, virtually no color - not what you saw at all. It wouldn't pop.
That's why I said the information in the raw file is accessible in ACR, using PV 2012, with a single instance of the file. It's possible to go in and get the data you need, to produce the image you want.