The Ins and Outs of Non-destructive Editing in Photos for Mac and iOS

In case you missed it, I wrote this article for the TidBITS website. The article covers non-destructive editing in general, but focuses on how Photos works, especially with extensions and external apps.

Feel free to comment here, or on their site.


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5 comments

  1. Robert Kroeger
    July 24, 2019 at 12:12 pm

    Thank you for writing this article. You are the only person that I have found in the blogosphere who has explained this clearly. I finally have a good mental model of how Apple Photos works with extensions.

    But understanding this just leaves me more frustrated about how I should go about managing my photos. My understanding is that if I use iCloud Photos to sync images, then the moment that I edit a photo with any particular editor T, then I can only change the images henceforth with T or all my edits will be destroyed. There’s no way that I’ll remember to always ever-more only use T.

    Does Catalina fix iCloud Photos? If not, can RawPower be used across devices the sidecars and images synced between devices without using iCloud Photos? Is the sidecar format open and documented so that different apps could change image attributes or raw exposure settings?

    1. Nik Bhatt
      July 24, 2019 at 7:39 pm

      Responses inline:

      My understanding is that if I use iCloud Photos to sync images, then the moment that I edit a photo with any particular editor T, then I can only change the images henceforth with T or all my edits will be destroyed.

      This problem exists with or without iCloud Photos. Photos can only store the adjustment information for one editor. If you use editor T, and then use editor V, then V will be using a JPEG generated by T. At that point, you cannot change the adjustments you made with T. You can edit again with T, but then you are stacking your adjustments on top of V’s JPEG.

      Does Catalina fix iCloud Photos? If not, can RawPower be used across devices the sidecars and images synced between devices without using iCloud Photos? Is the sidecar format open and documented so that different apps could change image attributes or raw exposure settings?

      Catalina doesn’t change any of these behaviors. RAW Power does not include a separate syncing system. I am looking into the ability to use RAW Power sidecars with another syncing system (e.g., Mylio), but I cannot say for sure when / if that will happen (I have other features I have to implement first). The sidecar format is not documented and it’s not easily read by other apps (I’m not trying to make it opaque – I use Apple’s archiving system which stores the data in a binary, as opposed to plain text)

  2. Rob Allen
    August 4, 2019 at 10:04 am

    Thanks for the article. Have I understood correctly, that if I use RAW Power as a Photos for Mac extension and then do some spot removal in Apple Photos, I can no longer adjust my RAW Power edits as Photos has thrown away the RAW Power adjustment-data?

  3. Nik Bhatt
    August 4, 2019 at 3:12 pm

    Hi Rob,

    Yes, you are correct. Once you do spot removal in Photos, a) you are doing the spot removal on a JPEG and b) the RAW Power adjustment data will be discarded.

  4. Rob Allen
    August 5, 2019 at 11:03 am

    Thanks Nik,

    I appreciate their problem, but it means that I’m looking forward to when RAW Power has all the features of Photos, so that I would never need to touch their edit tools!


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