Maybe a stupid question and I think that I know the answer, but I'm going to ask it here for clarification anyway. We all know that the .jpeg format compresses the picture data and that the data deleted is gone forever unless otherwise backed up with another type file that doesn't use compression. This can be a good thing or a bad thing depending on how you look at it. Anyway, this compression obviously takes place when the original edited RAW file is converted to .jpeg, but does this also happen every time I make a copy of the .jpeg file? If I do a simple file copy to move a .jpeg file from one location to another, do I get the complete original .jpeg data or is it compressed again even if the picture is unedited?

Wow, I didn't mean to start an argument on the virtues of editing RAW verses .JPEG! However, I have done quite a bit of editing with .Jpegs. In fact my first digtal camera only took .Jpegs, but I have since found that editing RAW files is far easier and more effective. My real purpose here was determine if my archive files that were edited as raw then converted to a JPEG were being compressed further when moved by file copy procedures. I think that it is a common practice to edit RAW then covert to JPEG for convenience and to save storage space, but maybe I should reconsider that as well in favor of .TIFF or similar low loss file formats. How about some feedback on what others do out there for archive storage. I always save my unedited raw files but have been saving my edited files as jpegs. I'd appreciate some feedback in that area without folks getting too worked up about it.

Jpegs are allowed in forensic work, but they can be shot as tiff in certain cameras. There is no "law" that says an image cannot be altered. Images can be altered to enhance the view/detail. You can adjust color, contrast, crop, sharpening, brightness, blur removal, etc. The key is to be able to record the most amount of detail and preserve it through the processing of the image. And of course, the original image must be preserved, unedited, to present alongside the edited one. Lossy formats, like jpeg are discouraged for some applications. When submitting any image that has been digitally enhanced, a journal specifying what adjustments were made must be presented along with the original.

Out of camera jpegs shot at large size and highest quality are often used by law enforcement and the legal system.

You can read about the process and exactly what is and what is not allowed here:

https://www.swgit.org/pdf/Section%201%20Overview%20of%20SWGIT%20and%20the%20Use%20of%20Imaging%20Technology%20in%20the%20Criminal%20Justice%20System?docID=35

https://www.swgit.org/pdf/Section%203%20Field%20Photography%20Equipment%20and%20Supporting%20Infrastructure?docID=47

https://www.swgit.org/pdf/Section%201%20Overview%20of%20SWGIT%20and%20the%20Use%20of%20Imaging%20Technology%20in%20the%20Criminal%20Justice%20System?docID=35

You are not making any sense, obviously have not done any of this kind of work, and have no basis for making any of the criticisms you are leveling at me. I suggest you quit while you are ahead. You are making less and less sense with each post.

Maybe a stupid question and I think that I know the answer, but I'm going to ask it here for clarification anyway. We all know that the .jpeg format compresses the picture data and that the data deleted is gone forever unless otherwise backed up with another type file that doesn't use compression. This can be a good thing or a bad thing depending on how you look at it. Anyway, this compression obviously takes place when the original edited RAW file is converted to .jpeg, but does this also happen every time I make a copy of the .jpeg file? If I do a simple file copy to move a .jpeg file from one location to another, do I get the complete original .jpeg data or is it compressed again even if the picture is unedited?