A word about how Lightroom uses files.
Lightroom is a “database of changes”. It never touches your original file (whatever format it is). We call that “non-destructive editing”.
Here’s how it works:
- You have your original file. Lightroom simply knows where it is (that is basically all that “importing into Lightroom” means!).
- Every time you make a “change” (like cropping, adjusting exposure, etc), Lightroom stores that instruction n its database (which it calls its “catalog”).
- What you see on your screen is that original file plus “what it would look like with that change”. But no new file is actually generated (except perhaps a little internal preview)!
It is only when you use a file that the changes are applied to make a new export file (or a printout, a web site, etc). This export file is made suitable to its particular purpose, and it is temporary: you create your export file, then use it, and then delete it.
- You always keep your original file intact.
- You do not fill up your disk with additional files.
- You can always review and redo any setting (including all the “RAW-settings”.
These are great benefits over the old ways of editing images, and they are why Lightroom and Aperture, which basically does the same, have taken over photographers’ workflow so quickly.