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

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Photos boasts non-destructive editing of photos, even when you use a Photos extension to make changes. While the basic non-destructive feature works well, there are some snags that can result in undesirable outcomes, particularly with RAW images and when using multiple editors.


This is a fascinating article which makes it very clear just what a powerful tool Aperture 2.x was (3.x was a step backwards in terms of interface), doing almost all of this in real time and allowing easy export of sidecars.

Working with any RAW converter which doesn’t store sidecars is a kind of digital deathwish. Sooner or later the program won’t be supported or the files will be moved and one’s edits will be lost. Sidecars should always be stored with the original images, in the worst case in a subfolder.

The most reliable partner (and affordable) for one’s images in Iridient Developer, who does not try to to manage your images. The Finder can do most image management especially with Raw Right Away Quicklook plugin, $7 in the App store. For culling of images on ingest, just grab FastRawViewer which uses standard XMP sidecars to store rating data. Rating and throwing away all the unneeded outtakes is probably the most important part of image editing in this digital age with hundreds and thousands of images.

For more serious RAW development the tools get expensive. DxO PhotoLab and CaptureOne are the market leaders among software one can purchase. Adobe will never get a foot back on my computer as I will not rent desktop software. Plus when I installed a trial to do some testing for an article, uninstalling Adobe CC was so incredibly complicated. Adobe CC is basically full time spyware that spends most its time watching everything you do on your computer and sending data back to Adobe headquarters. DxO PhotoLab is the least invasive (CaptureOne wants a few more permissions than I want to give).

Affinity Photo offers great Photoshop level tools for very little money and even includes a RAW converter. While Affinity Photo is a great Photoshop replacement, the front end RAW converter is no great shakes (probably Apple Photos level).

It would be great if Apple would respect its pro users and not neglect and then cancel important projects like Aperture. The FCP Studio 3 abandonment was not much better. It was five years before FCPX was even partially ready to replace FCP Studio. These antics lost Apple the post-production pole position and giving it away to Adobe with its Premiere and After Effects. Based on the mediocre condition of Apple Photos, I’m surprised that Apple allowed Nik to walk away. Apple need all the expert help they can get, to create even a shadow of what Aperture was.

Now that Nik’s explained the internal workings of Apple Photos, I’m glad I only used it for a couple of test projects to see how it worked.

Again, this is one of the most interesting and in-depth articles I’ve enjoyed on TidBITS for the last couple of years. Great look behind the scenes.

Seems like the obvious solution would be for Nik to build his own DAM into RAW Power.

Waiting, hoping, that Apple will fix things in a logical and useful way, is a fool’s game. They just don’t work like that. If you don’t believe me, just ask iWork fans, or iBooks fans … or one that always makes me smile; Apple Mail on Mac and iOS. No Rules on iOS, so if mail is collected first on iOS, before the Mac, then the Rules aren’t applied on the Mac. Sigh. It’s been years.

I understand that catering to Photos is very enticing, because a gigantic number of users have their images in there, but equally, that gigantic number of users isn’t really Nik’s base, which surely starts at the enthusiast level and not casual users. I’m a professional photographer and I know what it’s like when you try to explain even rudimentary aspects of Photo editing to a non-enthusiast, which is precisely why there’s a ‘Magic Wand’. Those people aren’t interested in RAW/JPEG/Tiff and all they entail.

It seems that Apple have shown at WWDC, with iOS and MacOS being brought closer together and with the addition of iPadOS, that users might easily be able to enjoy the benefits of iCloud for more specialised apps like RAW Power, e.g. Cloud synchronisation of edits etc. So maybe dump the extension idea and build RAW Power into a full-blown Aperture replacement. :smile: :wink:

That was a useful and interesting piece. The inability to layer on edits with multiple extensions is an ongoing disappointment with Photos.

I loved Aperture, moved to Capture One after, which is also a wonderful app.

Iridient Developer is the best for detail however, it smartly works alongside Capture One and if I plan on large prints, I use it for Raw processing. You choose Edit With and Capture one creates a Tiff of your specification to hand over. But ID is smart enough to grab the Raw file instead, process it and save back out a Tiff overwriting the original generated one for C1 to do further edits.

So as Nik points out you have to stay on your toes.

Can’t recommend DXO at all, had terrible experience with them.


A nice article. I have not even tried Photos, because I use Lightroom. So it was interesting to see how Photos handles RAW files. Unlike Photos, Lightroom enables you to maintain the bit depth of the original photo on export, though you can lower the quality of a JPEG, if you like. JPEGs have always been scalable because they were so often used with e-mail, especially in the early days when bandwidth was limited—and AOL limited file sizes. It seems obvious to me that Photos is intended for casual users. Why any professional photographer would use it is beyond me.

Lightroom is also flexible when it comes to sidecar files. Generally they are kept as metadata in the Lightroom catalog. But you can direct Lightroom to keep the sidecar with the image. Which is a good idea if you plan to move them around, say from one computer to another.

As for price, Lightroom, before CC, was priced in the middle, well below Capture One. Now Affinity Photo is the best value in a Photo developer. Unfortunately, it cannot read Lightroom metadata or sidecars, so while it is easy to switch from Photoshop, I’m stuck with Lightroom. Fortunately, you can get both Lightroom Classic, Lightroom (for mobile) and Photoshop for $9 a month in Adobe’s Photo package. Affinity Designer is a decent, affordable, replacement for Illustrator. And Affinity Publisher will soon replace InDesign. I love iDesign, but cannot afford CC at $20 a month. Maybe the price will drop when Publisher comes out of beta. But I’m not holding my breath.

Anyway, thanks for the article.

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I have become a big fan of Affinity Publisher after their beta. Really settled in on me even with InDesign sitting there on my Mac, albeit CS5.

For photoshop alternatives, we are lucky indeed with the options from Pixelmator Pro through Acorn to Affinity Photo. All are lesser apps than Photoshop but they all cover what I look for in a photo editor.

I’ve not had to subscribe yet to the Adobe world, can’t see myself doing it.

A number of years ago, I was embarking on a prestigious book project, which involved a lot of images to be taken using available light indoors, sometimes quite low-light (kitchen of the Ritz in Paris). Prior to starting, I wanted to make sure I was using the best RAW decoder/tool for this, so I spent an entire week, pixel peeping high-iso. Lr, Aperture, Iridient, Nikon’s own and a couple of others that were quickly discarded. What I found, was that it is very hard to reach conclusions, because the results can be very image dependant.

At the time, everything I read online said that Lr was tops for low-light/high-iso. This was actually the only thing that was conclusively wrong, as Aperture consistently produced far better output at high-iso. So that was the first surprise. I also found that Iridient did really well on some images and really badly on others. I didn’t own Aperture at that point, but ended up buying it for the project. Nikon’s own decoder produced excellent results too, with the nicest colour of all, but the difference compared with Aperture didn’t justify using an utterly horrible app.

One of the criticisms of Aperture was that it took so long for Apple to provide support for new cameras, but a couple of years later, I was told by a senior engineer at Leaf, that this was because Apple required a camera to be given to them for 2 months, so that they could produce high quality results. Adobe on the other hand … just added the camera’s name to the list of existing cameras and it was handled the same way as those other models (presumably until they could get hold of a camera). Terrific. I don’t know if this is still true, but I do know that Apple’s RAW decoder remains very good (and Nik’s RAW Power taps into it).

The images that I found to be the most useful for determining the quality of output from RAW, were anything with a mass of very similar textured detail (surprise!). The best was a large area of gravel (driveway of a house) and a recently tarmacked/resurfaced road, which had some quite large pieces of gravel (quite a rough surface). Shooting in both harsh and flat light tested these to the limit. Sometimes, a RAW processor would make the gravel almost completely disappear!! Interestingly, I re-ran some of these tests, using the Olympus OM1, when it was introuduced with pixel-shift. Using Olympus’s own software, could make the road texture disappear too! That was a surprise.

Regarding jeff5’s comment and exporting from Photos and bit depth …

I don’t use Photos, but I have seen on Nik’s twitter feed for RAW Power (his really excellent RAW decoding app that uses Apple’s built-in RAW processing) that with a significant change to Photos due with MacOS 10.15 Catalina, which will allow developers to access Photos database, he’s now looking into adding Aperture like DAM features to RAW Power. (Yes!!). So I spent a little while looking at Photos again and was quite surprised by some of what I saw and what this new access may mean. It’s actually potentially very interesting. Anyway … Photos Export dialog offers bit-depth choice for Tiff. If you’re working with JPEG, I can’t say I really see the point in working in 16bit. You’ve already made a lower quality choice.

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Interesting. I always found Aperture’s ability to recover detail in highlights or shadows superior to LR. That probably explains why.

I use Iridient now primarily given my Fuji cameras, the developer has focussed on getting the best out of files from the X-Trans sensor.

Excellent article, really interesting. And a great reference for the future.

This makes me so happy. I’m still on Aperture, and pondering what I’m going to move to with 10.15 dropping support. Still not found anything as good for me with culling and managing photos. Would love to see RAW Power grow into the DAM side of things.

Thanks for all the discussion and info. I, also, have been clutching to Aperture in its death moments. After trying a few applications, including Lightroom (standalone) and On1, I bought Capture One based on all the positive comments and reviews. I do love the Affinity Apps for manipulation of images as well as On1, but will use Capture as my base.

As with many photographers, I still have a problem with changing my workflow and have not moved everything over to an external folder to browse with Capture One. I also want to make sure it imports my images from Aperture, but I really like Aperture’s workflow and will have to wrap my head around a new process.

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I still have a problem with changing my workflow and have not moved everything over to an external folder to browse with Capture One.

Aperture makes it incredibly simple to ‘Move’, ‘Relocate’ or ‘Consolidate’ images. Moving ‘Managed’ originals, would let you try out Capture One for a large number of images. As long as Capture One is not actually altering the originals, then both apps can access the same images without any adverse consequences.

If you’re concerned about folder structure … you may want to rethink. Personally, I’ve always let Aperture do what it is designed for, which is to manage my images. All referenced images (in my case, all RAW files) are simply dumped at the root level of external disks. No folder structure at all. I use Aperture to organise using Libraries, Projects, Filters (Smart Albums) and Albums. Other file types (in my case Tiffs) are ‘Managed’ within Aperture. These tiffs are generally final images for client delivery or variations thereof.

The point is, to let the database front-end, handle the database and not try to use both the Finder and the Database do the same job … a recipe for problems. I do the same with Apple Mail. Everything just dumped in the In or Sent mailboxes and Smart Folders (permanent searches) to manage. (Most people don’t realise … but these can be And/Or)

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Thanks for the informative article. I didn’t know that Photos keeps the originals but only stores editing information. Two questions:

If I genuinely want to delete original photos (to save space), is that even possible in Photos? For instance, I often crop photos and I have absolutely no use for the original.

Somewhat unrelated, I am confused by the iPhoto-xxx.migratedphotolibrary files which apparently use the same photo files as Photos-xxx.photoslibrary files. If they do not duplicate the actual photo files, why are they showing (roughly) the same file sizes? (I have two of these which are ~80GB each, so do I save anything if I delete the migratedphotolibrary version? Are the photos stored only in the photoslibrary file?).


Deleting photos will delete the original, editing information and thumbnails / full size JPEG. However, if you delete the original, you will also end up deleting the edited image (cropped in your case). That’s not what you want. The only way I can think of is to export the image to the Finder and then re-import it. Once you have done that, you can delete the original. Keep in mind that you will not be able to remove the crop, because it has been burned into the exported image (this is one of the main advantages of keeping the original).

To your second question, the migratedPhotoLibrary and photosLibrary share their originals, using a technology called “hard links”. The sizes are about the same because a hard link acts exactly like the original file so its file size is identical in both cases (this is different from soft links or aliases). There is only one copy of the file, but both libraries refer to it. The OS keeps track of the number of hard links to a file. When all links are deleted, the file is finally deleted. You can delete the migratedPhotoLibrary when you are certain you do not need it any more. The images will be still be accessible to Photos.

(You can confirm all of this by making a new library with one image in iPhoto or Aperture, and then going through the export/import, or the delete process and then checking to make sure everything is fine in Photos. The originals are stored in the library in a folder called Masters)

FWIW, I use Photoshop all the time, but almost never edit the original photo. With linked photos, smart objects, layers, masks and adjustments, you can achieve a huge number of transformations to photos without touching a pixel of the original. Since seeing Deke McClelland apply a camera raw smart filter to a smart object, another huge range of possibilities opened. PSD files are unquestionably large, and they don’t (to my knowledge) play well with Photos. But still, I prefer the control that Photoshop provides over the other editors I’ve encountered.

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I like Iridient Developer as well, particularly for a quick one off file or for technical comparisons of lens transmission where it’s important to see the RAW data as is. Brian Griffith also offers a fair updates policy and wonderful support.

For serious work on high ISO files, where I’d like to retain colour and detail yet minimise chroma noise, nothing compares to DxO PhotoLab. Here it is head to head against C1 on a very challenging image (there’s a RAW file there which you can try in C1 yourself: if you have more success, let me know and send me your version, I’m happy to post a better C1 version).

That’s pretty thin material for a general damnation. Please explain.

Sorry Alec, no interest in a row on this, people have different experiences, their customer service was my issue. I’ve moved on, taken my losses, don’t expect to do more on it.