Apple iPhoto for iOS $4.99 / £2.99
Compatible with iPhone4 or later, iPad 2 or later, requires iOS5.1 or later (reviewed on iPad 3rd Gen)

Browsing and organising are particular highlights of iPhoto, thanks to multi-touch gesture support and fast operation. Image editing is restricted to JPEGs only; there's no Raw file rendering capability.

Apple has taken the well-known iPhoto Mac app that’s bundled with every new Apple computer and adapted it for the iPad and iPhone. Although the iPhoto app offers a range of image editing tools including, global and localised adjustment control (using multi-touch tools) there’s a lot more to it than that.

Despite sharing a name though, iPhoto for iOS does not integrate deeply with iPhoto for Apple's desktop computers. In fact, integration is limited to Apple's 'Photo Stream' service, which automatically synchronizes saved photographs between iOS devices and Mac desktops running iPhoto/Aperture. Synced images are saved at full resolution in the 'cloud' but are delivered to your iOS device at a reduced resolution, appropriate to the device. A 12MP 4.7MB JPEG file from the Fuji X-S1, for example, is delivered via Photo Stream at 3.1MP / 490KB to the iPad, but is available to a Mac computer (via Aperture/iPhoto) at full, original size.   

As you might expect, the social sharing aspects via FaceBook, Twitter, Flickr, and email are covered in iPhoto for iOS but Apple has also included an option to 'beam' images with editing adjustment metadata (sidecar files) between iOS devices, a potentially useful option for mobile photographers, especially. Moving RAW and large JPEG files off the iPad onto other iOS devices wirelessly via 'beaming' can be pretty slow though, and requires a lot of bandwidth.

If you want to transfer images to a computer, you can do this via USB option through iTunes (or better still using a RAW conversion utility – Aperture or Lightroom). 

Apple has also introduced Photo Journals into iPhoto for iOS - a cloud-based photo service with the option to add text alongside photos. Photo journals are published as web pages with a unique URL so they can be shared with anyone with a browser and net access.

(File) Size Matters

When images are viewed and edited in iPhoto, dimensions are restricted to a maximum of 19-megapixels (MP) per file for display. Images larger than this are scaled down to a quarter of the original image dimensions. Thus, a 22MP file will be downscaled to just 5.5MP, and a 36MP image from a Nikon D800 will be scaled down to just 9MP.

Image size restrictions also apply when exporting edited files. The maximum size image you can export after editing is 4096 pixels on the longest edge. Your original high-res images are still stored, and edited versions are simply saved as new files.

Before you write iPhoto off as an app exclusively for the mobile photography market, it has robust browsing capabilities that photographers at all levels can benefit from. 

Browsing and Organization

Apple is good at designing and implementing sleek UIs and iPhoto on the iPad doesn’t disappoint. Image organisation is one of the app’s strengths and the thumbnail browser and main viewer make it easy to quickly find, assess, flag, and caption images, though you can't rate them. 

You can mark images as flagged and tag them as favorites in iPhoto, or even hide them if you want to.

While you can enlarge images to check focus, composition and colour, and add albums in the Photos app, iPhoto also allows side-by-side comparison, image flagging (there is an option to flag individual images, those imported within the last 24-hours, last 7 days etc), and tagging of favourites. You can also add captions, view EXIF data and keep track of edited, flagged, beamed images, favourite, whatever is in your Photo Stream, your last import, all imports and so on. There’s an option to view images on an external display: using either a HDMI cable adaptor or using Airplay and Apple TV - potentially useful not only in the home but also for presentation to a client.

All this functionality is useful, but there is a little room for improvement. It isn't possible to create your own folders for example, so you're stuck with iPhoto's automatic organization of images as 'Events' by capture date (from the EXIF data) or as 'Albums'. Album names are pre-determined ('Flagged', 'Edited', 'Beamed' etc) so you can’t just add new Albums and name them as you might in the 'standard' iOS Photos app. It's worth noting though that any albums created in the 'Photos' app are visible and accessible in iPhoto.

Editing

Although at first glance it might appear that iPhoto for iOS can support the editing of Raw files, the truth isn't quite that simple. Most Raw files have an embedded JPEG for image playback and assessment in-camera and if you import Raw files onto your iOS device it is these embedded thumbnails that iPhoto works with. When you import RAW+JPEG images, iPhoto only accesses the JPEGs. (The RAW, of course, is still on your iPad/device and can be later imported onto a computer, but iPhoto only deals with the JPEG member of the RAW+JPEG pair.)  

Double-tapping on a thumbnail groups similar images and displays them in the main viewer, while a second double tap on the image zooms to 1:1 actual pixels, or, you can use a touch gesture to bring up a variable (1-3x) magnification loupe. All of it is typically sleek, but it’s also fast and efficient. The same goes for editing. Adjustments are non destructive until rendered for output, and it is possible to 'undo' edits - an Undo/Redo button is provided with unlimited history states. There’s also a 'revert to original' option.

Image editing and enhancement plays a big part in iPhoto, and while it's of little use in a Raw workflow, there's plenty here to like for those working on hi-res JPEGs and lets not forget the legions of mobile photographers who'll find compatibility with the iPhone and various sharing options all welcome additions.

Worth mentioning is a unique user-friendly loupe-based white-balance tool. Rather than use a traditional pipette/eye-dropper type tool, iPhoto has a loupe with cross hairs to sample colour for white-balance. You’re supposed to pick off a neutral gray, but it is easy/easier to drag it around as it updates the colour the whole time (in real time).

There's another loupe, too, for sampling skin tones.

There's a reasonable range of filters adjustments possible in iPhoto for iOS, including a quick auto-enhance for time-sensitive projects and quite a sophisticated levels tool with highlight and shadow clipping warnings. Sliders are used for quick global adjustments whereas brushes are applied using your fingertip are adopted for local adjustment.

Some adjustments, like sharpening, lighten/darken and desaturate can also be applied to the entire image, and some have strength sliders as well. In the main these worked well with only a slight delay but sometimes we needed to opt for the 'show strokes' setting when using some of the brushes, so we could keep track of where the effect had been applied. 

Local adjustments are made using brushes, you simply paint on the effect with your fingertip. However, some of the adjustments, such as lighten, darken, desaturate or sharpen (in this instance), can be applied to the whole image.

Conclusion

iPhoto for iOS is unashamedly aimed at non-professional image-makers and (inevitably) chiefly geared to the needs of mobile photographers. The lack of true Raw support is all but inevitable (none of the major photo editing apps for iOS allow Raw adjustment) and I doubt it will trouble the majority of people that download and install this app. 

I tested this app on an iPad, and iPhoto is the best app I've seen for browsing and organising photos on this device. But it's an effective editing tool, as well. If you have a JPEG workflow, say for example you work for a newspaper, where anything other than minor editing is frowned upon, then iPhoto on the iPad may prove very handy when you're working on location.

Even if you shoot Raw though, you shouldn't dismiss iPhoto for iOS out of hand. You can still import Raw files and use iPhoto to sort through images, for example, and to flag 'keepers' ready to transfer to your preferred Raw workflow utility on a computer (via USB, iTunes or if you shoot Raw only, via Photo Stream). My only serious reservations about iPhoto for iOS centre around the image size restrictions and lack of support for the original iPad, but at $4.99 we're not complaining.  

What we like: Price, sleek UI, quick to organise and browse, useful range of editing tools and sharing options

What we don't like: No support for original iPad, or raw rendering, resolution restrictions for display and output of edited images (orignal imported files remain stored at full resolution) Controls are small and cluttered on the tiny screen of the iPhone.