....are you still working with a raw file?? I dont spend a ton of time in PS, but does the .psd file still have the information and tunability that the original raw did??
At that point it's 'rendered' BUT if you hold the SHIFT (or is it the OPTION?) key while you're in ACR you will send a Smart Object to Photoshop instead of a regular image. That means you can go back and reopen it in ACR from PS. The button in ACR will change from Open Image to Open Object (or some verbage like that).
Without the smart object approach you would only have what is in the .psd file, which might be 16 bit data or 8 bit data, etc. So long as the most severe corrections have been done in ACR the post-ACR file would be quite manageable but you will not be able to recover from ACR cropping. The smart object approach will let you go back to your old raw files when a new ACR process engine comes along and re-do or edit the post-ACR changes that you made with the older process engine, without having to start from scratch.
