Just so you know what is needed when you work in CS2 with a RAW CR2 or NEF file, if you go back to any of your older RAWs, Lr will throw up a warning that you have an incompatible version of ACR don't worry. You will be offered two options, the one you need to chose is have Lr render the image.
Normally Lr passes the list of settings to ACR and that then opens the image directly in Ps. You do your edits and then hit save, and Ps then creates the file as set in the Lr preferences. As well as creating the file it is also added to the Lr catalogue and stacked with the original image. If you don't save the file then nothing is created at all. If you use Save As the file will be created, using the parameters that you choose, but the image will not be added to Lr. This is fine if the version of Ps is the same or newer than your version of Ps, since ACR can understand all of the commands that are sent to it. If though you have an older version of Ps the correspondingly older version of ACR will choke on any unknown commands. CS2 definitely counts as an older version.
So if you have that older version of ACR you get the choice of letting ACR go at it anyway, since the earliest version of Ps that has any support for PV2012 is the last CS5 release of ACR this is not going to be of help to you. So instead you have Lr render the image. This process is kind of the reverse of what happens when ACR renders. Lr creates the file, again based on the settings in preferences, adds it to the catalogue and then opens the file in Ps. You then just use the Save command in Ps and the file will be saved, Lr will see that the file has been changed and it automatically updates the preview that you see in Lr.
All that is fine for RAW files, but what if you are starting out with RGB files be they PSD, TIFF or JPEG? In that case you get a different option box come up, this has several options:
- Edit a copy with Lr adjustments. This applies any adjustments that you have made to the image in Lr and creates a copy of that file that it opens in Ps. It's pretty obvious when to use this option.
- Edit a Copy. This again creates a copy of the file, which is then opened in PS. In this case it doesn't incorporate any non destructive edits you might have added in Lr. You would use this option where your RGB file is the original file, such as an OOC JPEG, and you don't want to make any changes to the original image data.
- Edit Original. Use this option with care, since it just opens the file that is on disk in Ps. Use this where you have a system where you keep the master edit in an uncompressed (or at least lossless compression) format such as PSD or TIFF. If you realise that you need to make a change to this master edit you would use this option. If you use this option and you have made any edits to or VC's from it in Lr you must remember that when you save this file it will update all of those too, since they are all based on the same original image file. ONLY use this if you want to change the original file.
With all of these options you use the Save command so that the changes will make their way back into your Lr catalogue without the need for you to add them manually. This is why you have to use the save command, as where necessary Lr has already created the new file that you would get from using the Save As command. If you do an Edit Original, and then use Save AS you don't overwrite the original file, but the new file that is created at the end of the process is not added to your Lr catalogue. I never do this, since I'm likely at some point to accidentally save over the original by mistake, I use Ctrl+S a lot to save documents, and anyway if you use Lr for managing images you don't really want images on the system that are not in the catalogue.
You probably got a copy of Bridge installed too, I really like Bridge as a file manager for images and other Adobe file formats. One thing that I will suggest is creating a free Adobe CC account, since you can now download and use the latest version of Bridge for free. I like it because it will show you your RAW files as previews, and if you save the xmp files from Lr as well, it will show you your Lr edits, star ratings colour labels etc in the previews, along with all the metadata. You can even toggle to a full screen preview just by hitting the spacebar. I think that even if you don't regularly use Adobe products if you work with images and the like a lot is is well worth having as a file manager.