So Apple unveiled a couple of new iPhones last week - you may have heard. After lining up for the new flagship iPhone 5s last Friday morning (long story, even longer line...) I spent the weekend shooting with it, and in general it was a positive experience. I've been alternating between very big (Nikon D800) and quite small (Fujifilm X100S) cameras for the past few months and leaving everything behind except my phone - which I always carry anyway - is liberating, if a little nerve-wracking.

Apple's new mobile operating system, iOS 7, is a significant visual refresh compared to what I'm used to, and after diving pretty deeply into it over the past week or so, it is obvious that the company is investing a lot of energy in highlighting the photographic capabilities of its hardware and software. The iPhone 5s's camera app is available right from the lock screen (this has been a feature for some time now) and in use the camera is fast, responsive and generally very accurate. In good light images are really nice, low light shots are decent if not outstanding, and the new dual-color flash definitely makes a difference to low light portraits. You'll find a link to the full gallery of pictures taken in a range of lighting conditions above.

To take a panorama in iOS 7 you just select 'pano' from the camera options, line up your shot vertically and slowly sweep from left to right (you can change the direction if you like by tapping the arrow). While you're sweeping across the scene, make sure to keep the arrow centered on the yellow line as closely as possible. You'll be warned if you don't, and prompted to slow down if you're going too fast. 

We'll be publishing a full review of the iPhone 5S on connect.dpreview.com in good time, but for now, before the week gets too busy I want to take a quick look at what I think is the strongest feature of the new iPhone: its panorama mode. Now, automatic panorama modes aren't new, they've been around for a while, and the feature is now almost standard in most mid-range compact cameras, many smartphones and even some mirrorless cameras. iPhone users have had the functionality since the launch of iOS 6 last year. But the panorama mode in the iPhone 5s is a little different, and that little difference is seriously impressive.

It got a little bit buried in the presentation of the phone (Shiny! New! Fingerprint sensor! Comes in gold!) but for me, the iPhone 5s's panorama mode is definitely its most interesting photographic feature. Why? Well, it's just ridiculously good, that's why. Very fast capture (30fps as you pan across the scene), a simple and effective UI, and spookily accurate stitching make the mode useful, but the killer feature is what Apple is calling 'dynamic auto exposure'. 

Available in the iPhone 5s only (presumably because of the processing power required) dynamic auto exposure is basically what it sounds like - exposure is automatically adjusted dynamically across a scene, as you move the phone to create the panorama. So if your scene incorporates bright and dark areas across its span, the phone will take that into account and adjust the metering as you go, delivering a final composite image with a balanced exposure. 

This panorama from the iPhone 5 shows overexposure and highlight clipping as the phone was panned from right (where exposure was initially locked from the shadow area) to left. 
The iPhone 5s has done a much better job, delivering 'normal' midtones across the frame, and much more tonal variation in the very bright sky. 

As you can hopefully see from the images below, the iPhone 5s's dynamic exposure panorama mode works very well. That's why there are so many panoramas in the samples gallery we published recently, and why I've spent the past few days taking panoramic shots of pretty much anything I can! Keep an eye out for more coverage of the iPhone and all (other) things mobile on connect.dpreview.com

A late afternoon panorama from the rooftop of our Seattle offices. The iPhone 5s has accurately balanced the exposure from the shaded area on the left to the brightly lit highlight areas on the right. There are a couple of stitching errors in the decking on the left, but otherwise this panorama is impressive. 
This indoor panorama highlights the dynamic auto exposure well, as we move from a dark interior to a brightly lit cityscape back to an interior again on the right. The single burned out area mid-right is where the sun was positioned, just behind some thin clouds. 
This panorama was taken in the middle of a very bright day. The sun was to my right, and you can see that the iPhone 5s struggles to completely balance the exposure at the extreme right, although the light, washed-out area on that side of the frame is partly caused by lens flare, not overexposure.
The complex shapes in this panoramic shot of an outdoor art installation are handled very well by the iPhone's panorama mode.
The sun is just peaking in at the extreme right of this late-afternoon shot, but exposure is extremely well-balanced given the wide effective focal range. And no purple flare - which is nice. 
The iPhone 5s's panorama mode deals well with movement, and is generally very good at eliminating 'ghosting' caused by elements of the scene changing position across the panorama. The exception is movement in the same plane as the phone when it is being panned, especially in subjects relatively close to the camera.

The couple with the stroller at mid-right were crossing left-to-right at almost the same speed as I was moving the phone. They've become a little mangled as a consequence. The figures in the middle of the frame, on the other hand, are perfectly rendered.
At a show inside a local theatre the iPhone 5s made an excellent job of stitching this highly complex panorama. When the lights went fully down a few minutes later the phone couldn't cope, but here with house lights on, but dim, exposure is accurate.