On 5 February 2015, Apple released a beta version of its new app to developers and select members of the press. Announced last year  for both of Apple’s other existing photography apps, iPhoto and Aperture, Photos had originally been promised for early 2015 (see “ ,” 2 June 2014). With this release, we now know that it’s coming this spring as a part of the OS X 10.10.3 update.
The prospect of moving photography apps is daunting, but even die-hard users of iPhoto and Aperture would probably admit that the old versions had become increasingly slow and wonky. Rather than rip them apart, Apple decided to start fresh, which may sound familiar to users of many other Apple apps, including Final Cut Pro and both the iLife and iWork suites.
A Bridge to a New Land -- When you launch Photos for the first time, the app will automatically upgrade your iPhoto library. (If it notices you have more than one library, it’ll prompt you to choose which you’d like to upgrade.) After the import process, not only will all your photos and videos be present, but albums, folders, books, cards, calendars, and slideshows will also make the transition.
Imported iPhoto and Aperture libraries remain intact and usable, but it’s a one-way import — the older app’s libraries don’t sync with the Photos app, so if you add a photo in one place it won’t show up in the other. The Photos import process is friendly when it comes to disk space — it doesn’t duplicate the photos it imports from iPhoto and Aperture, so you don’t lose precious storage space.
Some aspects of iPhoto and Aperture won’t make the move to the new app. Photos replaces star ratings with favorites (indicated by a heart icon). Star ratings and flags from iPhoto and Aperture (as well as color labels from Aperture) will be mapped into keywords and assigned to each photo, so you can still search for images containing that information.
Photos feels more like the Mac version of the iOS Photos app than either iPhoto or Aperture, at least when browsing your photo library. Zooming out (which you can also do with a pinch on the trackpad) presents you first with a series of short events defined by location. Zoom further out and you’ll see larger spans of time and a list of locations. One more zoom and you’re left with a giant wash of photos separated by year.
Underneath the Albums tab (or, alternatively, in the sidebar if you choose Show Sidebar from the View menu) you’ll find your media organized in a few different ways. All the various media types supported by iOS cameras — panoramas, videos, and slo-mo videos — are segmented into their own smart albums. There’s also an automatically generated Favorites album, an album containing your most recent set of imported media, and the familiar Faces tab that’s been more or less brought straight over from iPhoto. Gone is the capability to show all photos by location on a map, but you can click any event in the Photos list to see a map containing the locations of all the photos from that particular event.
Photos in the Cloud -- The banner feature of Photos is its integration with Apple’s iCloud Photo Library service. You can (optionally) set Photos to automatically upload your photos to Apple’s iCloud servers, where they’re backed up and accessible from iOS devices. (iOS device access will be included in iOS 8.2, an update that will presumably be delivered around the same time that Photos is released.)
When you sync Photos with iCloud, you have two options regarding photo storage: Download Originals to This Mac ensures that a full-quality original version of every file you have in iCloud will also be stored on your Mac; Optimize Mac Storage keeps full-resolution photos and videos in iCloud, though they might also be stored on your Mac “if you have enough space.”
It remains to be seen exactly how Photos determines whether you have enough space, and whether it’s just caching photos or if it truly makes a judgment about how much free space you have before deciding to hold onto your files. As someone with approximately 700 GB of family photos and a bunch of Macs with small flash-storage drives, I’m excited by the possibility that I can have access to my entire photo library on all of my Macs and iOS devices, even though they don’t have enough space to hold the entire library.
Photos also integrates with all the photo-sharing features available on iOS. If you check the iCloud Photo Sharing box in the Photos app’s iCloud preferences tab, you’ll see the same shared albums that you see on your iPhone or iPad. And you can use the Share command to share media items with Flickr, Facebook, and Twitter.
Editing Options -- Photos has a nice suite of photo-editing features. For people who don’t want to spend time tweaking photos, there’s a one-button enhance, an auto-crop feature that even straightens tilted images, and a set of Instagram-style filters that apply a whole slew of effects at once.
Those who want more control over their images will prefer the Adjustments section, which includes options for lightness, color, levels, white balance, sharpening and definition, noise reduction, vignetting, and black-and-white effects. Finally, there’s a Retouch tool that lets you make very basic edits by clicking around and hoping that it does the right thing.
If you want to edit your photo in an external tool such as Photoshop, there appears to be no way to do that, at least in this beta, beyond dragging an image out, editing it, and then dragging it back in. Here’s hoping Apple allows an external-editor feature or support for image-editing extensions of some sort in the future.
The Need for Speed -- With every successive version of iPhoto Apple claimed that it was faster than ever before. Unfortunately, we all kept taking new photos, and our iPhoto libraries kept swelling, and iPhoto never seemed to keep up.
Never say never, but in my tests with a 5,450-image library, Photos seemed downright fast. Scrolling never lagged. Zooming in and out was speedy. Here’s hoping that continues to apply to libraries with tens of thousands of photos.
It’s still a beta version meant only for developers — and it shows. I had problems importing one of my large iPhoto libraries, and the app crashed when I tried to import a few thousand photos from a folder. A few times, I opened the app to find the main Photos view completely empty, though all of my photos showed up when I clicked on All Photos. If you have access to the beta, I strongly recommend that you not entrust your primary photo library to it.
Fortunately, Apple has more than four months until its self-imposed deadline to iron out most of the wrinkles. But right now, Photos looks like a promising attempt to stitch together photo libraries across Apple’s devices and on the cloud.
You may have noticed this is my first article for TidBITS since 1995, and it’s also a good excuse to mention that I’m also diving into my first Take Control book, a Crash Course about Photos. So if you see any particularly cool features or have any significant concerns you’d like me to examine while writing it, let me know in the comments.
[Update: Over at Six Colors, I've written more about and  from a variety of sources. -Jason]
[Jason Snell was lead editor at Macworld for more than a decade and has written about Apple and other tech companies for two decades. Now he writes at Six Colors. He’s also the guy who runs The Incomparable podcast network, which is all about geeky pop culture, and hosts the Upgrade and Clockwise tech podcasts.]