1 of 16Screenshot by Lori Grunin/CNET
Step 1
This is what you first see when you install Carousel on any device.
2 of 16Screenshot by Lori Grunin/CNET
Cost
For full capabilities--the capability to create, share, and edit images in Carousels--you get 30 days free, after which there are monthly or annual subscription fees. The $6/$60 sub fee is an introductory price. In January, it's going up to $10/$100. But if you subscribe for another two years, you can lock in the introductory price for that period.
3 of 16Screenshot by Lori Grunin/CNET
Location services: On
This is probably a personal pet peeve, but I don't enable Location Services on any of my devices. If a mapping app can operate without it, why can't a photo-sharing app?
4 of 16Screenshot by Lori Grunin/CNET
Creating a Carousel
Adding photos to a Carousel is simple. You can pick from any Album or capture directly into it on your iOS device or off the hard disk or media on an OS X system. Unfortunately, there's no direct access to iPhoto or Aperture libraries.
5 of 16Screenshot by Lori Grunin/CNET
View
Once you've added your photos, you can view them by date. That's it. You can flag photos, but not filter or sort on flags. There are no keyword or captioning options, and if other users flag particular photos, you can't figure out which ones they were.
6 of 16Screenshot by Lori Grunin/CNET
Presets and effects
Adobe provides a variety of preset effects, which are all basically variations on brightness, contrast, saturation, white balance, and so on. They're a bit boring, but you can also just use them as starting points for further changes.
7 of 16Screenshot by Lori Grunin/CNET
Adjustments
Carousel provides access to a decent set of adjustment tools, though Adobe should probably put red-eye removal on the list for the next revision. For each of the three main adjustment tools--white balance, exposure, and contrast--there's a submenu that you access by touching the double arrows. One really nice feature is the ability to choose auto independently for white balance and exposure. The edits are nondestructive, in that they don't affect the original image and can be changed at any point.
While I generally like the adjustment tools and interface, you'll notice that there's no scale or visual cues, other than intensity, on the slider UI. It would be nice if, for example, white balance showed the extents for warm and cool.
8 of 16Screenshot by Lori Grunin/CNET
Contrast
For contrast, you can also adjust clarity and vibrance.
9 of 16Screenshot by Lori Grunin/CNET
White balance
You can change the color temperature and tint of a photo.
10 of 16Screenshot by Lori Grunin/CNET
Exposure options
You can independently adjust highlight and shadow exposure.
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Straighten and crop
Straightening, cropping, flipping, and rotation round out the retouching tools.
12 of 16Screenshot by Lori Grunin/CNET
Sharing on iOS
In addition to Carousels, you can share photos via more-traditional means, including e-mail, Facebook, Twitter, and Tumblr on an iOS device.
13 of 16Screenshot by Lori Grunin/CNET
Sharing on OS X
On an OS X machine, you can export a file to the clipboard on OS X. Of course, you should also be able to send photos to the services on your desktop, but as far as I can tell, you can't.
14 of 16Screenshot by Lori Grunin/CNET
Sharing
This is the e-mail received by the invitee when you share a carousel. If they're already running the app, it will display a message allowing them to reject or accept the invitation.
15 of 16Screenshot by Lori Grunin/CNET
What you see on the iPhone
The gallery display on the iPhone looks similar to that of the iPad. View Status shows you thumbnails of the images waiting to be imported.
16 of 16Screenshot by Lori Grunin/CNET
iPhone UI
The one notable difference between the iPhone UI and the other devices is that adjustment controls are tabbed to conserve screen space. The icon next to the Apply button gives you before and after previews.