is it possible to go from lightroom to photoshop and back to lightroom?

The answer: YES but...

I use LR for my basic editing (in fact all that can be done in LR). Then, I open the image in Photoshop and do my photoshop edits. I save back a (layered if appropriate) TIFF-file. I normally do not continue editing the original file. The TIFF file can be further enhanced using LR. I try to avoid that. I should, however, test this out...

Yes you can, BUT what do you want to do when you return to Lightroom? I recommend only using Lightroom for file management upon return because Lightroom can not deal with layers. If your Photoshop file has layers you probably want to avoid doing further edits in Lr.

Of course rules are made to be broken. If you understand the relationship between the applications, and the rule about layers then you can break it. If this doesn't make sense, then stick to the following workflow for now.

1. Do overall general edits in Lr

2. Send to Ps for detailed retouching, selective editing and compositing

3. Return to Lr for file management

Just so your are aware Lightroom and photoshop function completely differently.

a-: Lightroom manages the files that it processes via a catalog file which is a data base fore storing information about your image files. i.e where the files are located and other info about the files. All the work you do with the files adding keywords and other metadata, edits you perform in processing and enhancing the image is stored in the catalog file. It is a totally nondestructive editor and never makes any alterations to the actual original. The information is in the catalog file.

b-: Photoshop on the other hand stores this information in the file header for jpeg, tiff, psd, png etc and in sidecar .xmp files for raw files. After working with a file in Photoshop you have to save your work and this will result in the original file being altered, or alternatively you can save as and create a new file with the edits. In this respect it is referred it is referred to as a destructive editor. The information is in the file.

c-: You can use the edit in function in Lightroom to send file for further editing in Photoshop however you always have to save woug work when you have finished working on them and this process will create a new file with your edits from Lightroom and Photoshop.

You can go to the link below for video tutorials for working in Lightroom and Photoshop.

Lightroom Training Videos « Julieanne Kost's Blog

I ju8st noticed that additional info has been posted earlier.