The term "non destructive editing" is currently used in many discussions. It simply means that imaging tools leave the original image untouched and only stores instructions to recreate the final image.

RAW converters work for a long time this way. The challenge is where to store the instructions.

We mainly look at ACR, Capture One, RawShooter, LightZone, RAW Developer, Aperture and Lightroom.

There are a couple of options used by today's tools:

• Have images and settings data inside a closed database: Aperture

  Advantage: Settings and images keep well tied together

  Disadvantage: Interfacing with other outside applications can be hard at times

• Have settings data inside a closed database and pointers to images outside this database: Lightroom

Advantage: Settings well managed

Disadvantage: Image links can get lost

• Store settings inside the RAW files: Nikon Capture, Canon DPP

Advantage: Images and settings are one unit

Disadvantage: if all tools do the same we need clear standards as otherwise other tools might destroy the information. There also may be locking issues. Any write to a file can in certain circumstances destroy the file (image loss). Sometimes other tools cannot read the modified files (recently Aperture with RAW files that changed the IPTC information).

• Keep image settings in a system database: ACR (one option), Capture One, Biible (one option)

Advantage: Local folders get not polluted with settings files and you can allow editing of offline files

Disadvantage: Hard to move to other machines (Bridge allows for this purpose an export)

• Keep settings in so called sidecar files: ACR (second option), Bibble (other option), RawShooter, RAW Developer, LightZone

  Advantage: Original RAW file does not get touched

  Disadvantage: If you copy images you also need to copy the settings files. Folders get polluted with many different settings files.

   

The last option is the easiest to implement and the most popular. Here is how it could look like:

One image and 4 different settings files

The sidecar file system work fine if you stay with just one single raw converter and hardly use external image organization tools. But assume you copy or move files with a third party image organization tool like Extensis Portfolio, iView Media Pro or Photo Mechanic then most of these extra settings files would be lost (means left in the old place or would not be copied). Some tools like Photo Mechanics at least recognizes the XMP files.

We will start to lobby the idea to support also the sidecar files of popular third party RAW converters and hope to report the first success pretty soon.

What about Aperture and Lightroom?

• If you stay inside the closed world of Aperture all is fine. But we find that Aperture does not really integrate well with outside tools (e.g. other RAW converters)
• Ligthroom is more open but does not right now allow to organize (e.g. move/copy) the files that the Lightroom library refers to (this may change). But even then we are not that optimistic it will have support to recognize third party sidecar files soon.

Right now "non destructive editing" is nice to have but no real pleasure if you manage many images.