No again. I know Lossy and Lossless and the difference. I am not talking about the Raw file. I know Raw files are not changed and you can start from scratch with a Raw file ,no matter how many times you have edited that file, it remains intact. I am only talking about the difference between Tiff and Jpeg files. You save a file to Jpeg and all the editing steps are no longer visible. When you reopen the Jpeg all you see is the file, no editing steps you took. When you open a Tiff file in your editing program you see every step you took in your editing process, as long as you did not merge or flatten it. You can certainly continue to edit the Jpeg but you can not go back and edit a particular step. With Tiff, all your steps are saved and you can tweak any one of those steps.

I have to admit that before I went all crazy, I took a look at your website and could tell by your photos that you weren't a neophyte who got flummoxed by confusion. Your stuff is pretty good, so I realized you'd been around the block, so to speak. That's when the light dawned that you were thinking of a feature of LR/PS, possibly, and so I looked THAT up, and there it was. It's interesting that both of us were right, and neither of us were wrong, even through the confusion. Now, the question is, have we completely baffled the OP and all the followers of this by now mind-boggling thread? Or has everyone else moved on to discussions of Canon vs Nikon, and left us to our own designs?

Cheers.

Sorry, but the highlighted statement is not correct. When you edit a raw file, whether you save to TIFF or JPEG is immaterial. You are confusing the LOSSY (compressed) saves that happen to a JPEG file with the LOSSLESS (uncompressed) format of a TIFF file.

An edited raw file will always be re-editable, since the changes do not overwrite original data, but are saved as a sidecar or other mechanism.

UPDATE:
Ok, I've gone back over your original statement, my first reply, your response, and now my 2nd response. I am completely puzzled by your statement that TIFF files somehow retain all the editing actions that you make on them.

Are you saying that you can edit a raw file, make a bunch of changes to it, save the edited raw as a TIFF file, and then open the TIFF file and be able to UNDO the changes that were made while you were editing the raw file? That doesn't make any sense.

Or are you saying that you can open a TIFF file, make a bunch of changes, save it, then re-open it and undo those changes? Huh? I've never heard of this capability. I know all about the ability to UNDO in varying amounts, during a SINGLE session with various editors, but I've never heard of the ability to 'store' edits to a TIFF file and then re-open it, ostensibly days later, and UNDO those individual editing actions.

Now, it may be that your P/P program somehow saves actions done against a TIFF file, so that you can reopen that same file later and undo those actions, but that's a function of the P/P software, not a TIFF file generically.

I do not use Photoshop or any of its derivatives so perhaps that's where this confusion comes in?