I can't see the adjustments under the Adjustment tab in Aperture. Where is the data?

Question

Several months ago I dragged photos from Aperture into a Burn Folder on my Desktop. Today I dragged the photos from the Burn Folder on my Desktop into Aperture. My photos are all still edited, but I can't see any of the adjustments I made under the Adjustment Tab in Aperture. Where is that data? How do I get it back?

Answer 1

I'll cover most of this because I'm too busy to trim it, but be sure to read Léonie's post.
barbst wrote:
Can you explain to me the difference between a Preview and the Master image? I checked my preferences and they are set "Photo Preview: Half Size" and "Photo Preview quality: 8 Medium".
The Master is now known as the Original.  (Apple changed the term.  I don't know why.)  The "Original" is the term Aperture uses to designate the image-format file you imported into your Library.  When you import, Aperture creates a record in its database and creates an Image that you see in the Browser and the Viewer.  Every Image has an Original.
Aperture creates additional files that it uses.  Among these are a Version, which is a text file containing instructions regarding adjustments and metadata changes you make, some thumbnails, which are image-format files in small dimensions, and a Preview, which is a JPG-format file that is automatically updated to include any adjustments you have made.
The Original is _never_ altered.  Aperture is a _non-destructive_ photo developing workshop.  "Non-destructive" means that your original files (the ones that Aperture calls "Originals" once you import them) are never altered.
The Preview is _always_ altered.  It always is updated to include all the adjustments you have made to any Image.
As you know, you set the JPG parameters (size and quality) for your Previews in Aperture's preferences.
Does this mean that all the photos I have dragged to Burn Folders and burned to DVDs are lesser quality than my Masters in my Aperture Library? I thought I was backing up the Masters!
Sorry for the bad news, but the latter is not correct, and the former is.  When you drag an Image from the Browser or the Viewer, Aperture creates a copy of that Image's Preview.  (The User Manual should make this clear.  Currently it is incorrect.)
Note, too, that your Masters (now "Originals") are never altered.  What you might have wanted to back up were the Images in your Library.  Now -- get ready for the weird part -- those Images do not exist as image-format files.  There is no file that we can access in order to to back-up an Image.  You can either create share-able image-format files from your Images, and back those up, or you can back up your Aperture Library, which, when restored, will give you the opportunity to create share-able image-format files from your Images.
Aperture is structured this way -- it saves the imported file, untouched, and text instructions telling it how to create your Images on-the-fly -- specifically to save the space you would need to store full-size files of every Image in your Library.  Rather than save "the thing itself", it saves just what it needs to create "the thing itself".  The storage savings are enormous.
This is why your workflow is (in general): import, make adjustments and add metadata, sort, group, and organize, and export _only when you need an image-format file to share with another program_.  You then share that file, and delete it (because if you need another, you can create it by exporting from Aperture).
How about when I drag photos from my Aperture library to an external hard drive icon on my desktop? Am I dragging the Masters or Previews? If so, are the Previews lesser quality than the Masters in my Aperture Library?
When you drag Images from Aperture, you create copies of those Images' Previews.  If you haven't made any adjustments, then they are Previews of your Masters (now called "Originals").  But Previews are JPGs with the dimensions and quality you told Aperture to use, whereas your Originals are whatever format, dimensions, and quality they were when you imported those files.  The quality of an Image's Preview is always less than the quality of that Image's Original.  (I'm using "quality" to mean "amount of useable data".)
You should test this right now.  Create a new Finder folder.  In Aperture, select an Image with adjustments applied.  Drag it into your newly-created Finder folder.  Then export it's Original into the Finder folder (File ▹ Export ▹ Original).  Then export the Version with whatever settings you want (File ▹ Export ▹ Version).  Compare the three files you just created.
I think I'm going to be sick! Please tell me it isn't so! I have 1000s of beautiful photos from trips on both DVDs and a Western Digital external hard drive, but I dragged them all from my Aperture Library to either a Burn Folder or a Western Digital icon on my desktop, then I deleted the originals from my Aperture Library. I did this to make room on my Mac Book Pro hard drive. This is how Apple One on One taught me to backup my photos!
I'm sorry  .
To back up your Originals, back them up.  They are files.  If they are in your Library, they get backed up when you back up your Library.
To back up your Images, either make files from them, and back up those files, or ... back up your Library with the knowledge that that way you can create new files from your Images after restoring your Library from your back-up.
To shrink the size of your Library so that it leaves more space on your system drive:
- remove un-needed Images
- relocate some Images' Originals to a second drive (almost always external).  Aperture makes this easy to do.
Alternative, put your entire Library on a second drive.  Libraries on external drives connected via USB-3 or Thunderbolt work fine.
In general, a photographer's commitment to an image-management database system (of which Aperture is one) is complete:  it works best when it is all-enclusive.  I recommend against removing Images from your Library either to save space or to archive them.  My personal Library catalogues all my photographs.  Using it I can find, and make available, any photo I've taken and decided to keep.  Once I decide to keep it, it stays -- forever -- as a record in my Library.
Note that your "Library Set" (I just made that up, but it should exist) includes your Library package (that shows as a file in Finder) and any Referenced Originals that belong to Images in your Library.  You must back up your entire Library Set.
The Geniuses at the Apple Store generally do great jobs in demanding circumstances.  They are, by need, generalists who must be reasonably adept with a lot of software.  It seems you were (badly) misinformed.  Please recommend this post to the one who coached you, so that s/he makes sure that others aren't similarly misled.
HTH,
--Kirby.