You are correct in your general understanding of Versions. They are actually text files of instructions and metadata applied to the Original on-the-fly.
Aperture makes a consistent (afaict) distinction between "editing" and "adjusting" Images. Adjustments are saved to the Version file. When you edit with a plug-in or an external editor, Aperture creates a new Original (and, as with all new Originals, a null Version).
But note that Aperture never shows you the storage requirement of the Version text file. The storage requirement listed in the metadata is for the Original. (You can verify this by cropping an Image. The storage requirement does not change.)
Using Photoshop, you have three (probably more) choices when saving externally-edited Aperture Images. From smallest to largest storage needed:
- flatten the file before saving
- save layers
- use Smart Objects
Added:
If you want to conserve storage space, you might try setting Aperture to create 8-bit TIFFs for external editing ("Aperture➞Preferences➞Export➞External Editor File Format").
HTH.
Message was edited by: Kirby Krieger