Camera Features

While many Android phones take an everything-but-the-kitchen-sink approach to piling features on their camera app, Google’s native app remains fairly restrained, closer to the design philosophies seen in the Apple and Nokia apps. Unfortunately, Google doesn’t pull off Apple’s graceful usability or Nokia’s advanced photographic finesse.

HDR+

Thanks to their small photosites, all phone camera sensors struggle with scenes that include both very bright and dark areas. High dynamic range (HDR) modes try to offset that weakness by taking different exposures and blending them into a single image with (hopefully) intact highlight and shadow areas. With the Nexus 5’s “HDR+” feature, Google aims to expand HDR’s mandate to improve other image quality aspects and include low-light photography.

The Nexus 5’s implementation works well, achieving a marked increase in dynamic range. Besides the dynamic range boost, the HDR+ images tend to be more saturated (though usually not over the top). There’s also an efficient sharpening algorithm at work: the output can look at little over-crisp at 100% viewing, but at normal magnifications it just looks nicely sharp. 

There’s plenty of highlight clipping in this photo of a difficult scene taken in normal mode.
100% crop
HDR+ increases the camera’s dynamic range in the highlight areas and produces a sharper, punchier image. However, it actually buries some shadow detail that was visible in the normal mode shot.
100% crop

HDR+ appears to take advantage of noise averaging to produce cleaner, more detailed images. We’ve seen image stacking used to good effect in low-light shooting before, but the idea of rolling it into the HDR mode makes a lot of sense. While obviously useful in low-light, high-ISO situations, the effect is noticeable in bright sun as well: for example, the noise that appears in a dark blue sky at base ISO is reduced in HDR+ shots.

The Nexus 5’s sensor has enough dynamic range to deal with this scene in normal mode, but noise is visible in areas of even tone.
100% crop
HDR+ averages out the noise without sacrificing fine detail.
100% crop

At higher ISOs, the payoff seems to be improved detail retention more than lowered noise, mainly because the Nexus 5’s noise reduction is quite aggressive (with collateral damage to image detail) in normal high-ISO captures. It’s also worth noting that the HDR+ mode sometimes raises ISO in low light situations, presumably to get a hand-holdable shutter speed for the longest exposure. That makes an apples-to-apples comparison with the normal shooting mode nearly impossible.

The Nexus 5 blurs some detail to remove noise in this normal mode night shot.
100% crop
The HDR+ version isn’t really any cleaner, but colors are more saturated, there’s a bit more fine detail, and dynamic range is expanded.
100% crop

The multi-exposure nature of HDR often means that moving objects create strange artifacts in the final image, but Google’s HDR+ algorithms appear to have largely solved this problem. We didn’t notice a single instance of the kind of doubling you’d expect from moving objects in an HDR shot during our testing. The phone appears to isolate moving objects and “paste” them from a single frame in the burst. As a result moving things sometimes appear noisier than the rest of the scene (since they don’t benefit from the image stacking noise reduction), but this is far preferable to pedestrians with three legs.

HDR+ deals well with movement in the scene. There are no “ghosting” motion artifacts, but zooming in reveals a lot of noise on moving objects.
100% crop

Since HDR capture involves taking multiple exposures, it’s inevitably slower than conventional shooting modes. The Nexus 5 is pretty quick, taking about 1.5 seconds to shoot an HDR+ image, though it can’t match the iPhone 5s’ remarkably snappy HDR mode.

The Nexus 5’s HDR mode is impressive, but there are a couple of caveats. Firstly, HDR+ output is slightly cropped, presumably to give the phone some leeway when aligning the component images. This results in a slightly narrower field of view and lower (7.5MP) resolution. Also, the camera doesn’t save a normal, “middle” exposure along with the HDR capture, so there’s no recourse if you don’t like the HDR treatment.

Panorama

While HDR+ is a notably effective take on an increasingly common function, the Nexus 5’s panorama mode feels like a desultory check mark on the feature list. Yes, you can shoot panoramas with the native camera app. But compared to the best of the competition, the results are underwhelming.

That little window swimming in a sea of black is your panorama preview image.

The first clue that the pano function isn’t going to bowl you over is the preview window, a postage-stamp-sized affair reminiscent of online streaming video circa 1999. At least you can hold the phone in portrait or landscape orientation, and pan in any direction.

The end result is around 3000 pixels wide and about 580 high (with the phone held in landscape orientation) or 770 (in portrait). At most, the total image weighs in at a bit over two megapixels. With the best of the competition delivering 15, 30 and even 60MP pano shots that you can explore like a Where’s Waldo spread, the Nexus 5’s pano output is a bit disappointing. At least the stitching is competent, though the low resolution could conceal a multitude of sins.  

The Nexus 5’s pano mode is underwhelming in terms of resolution, but it does a decent job of correcting for different exposure requirements across the scene.

A perennial challenge for pano modes is getting exposure right. Often the sweep of a scene will have a wide range of brightnesses, so using a single exposure across the whole pan can result in areas of over- or under-exposure. The Nexus 5 tries to compensate for that, but the results are uneven. In the image above, for example, the exposure is set for the left side of the pan, then darkened as the camera reaches the brighter center with a fairly smooth transition. However, the right side of the pan ends in shadows, as the function doesn’t lift exposure to deal with the darker part of the scene. 

Photo Sphere

Photo Sphere creates immersive 360 panoramas by stitching together dozens of photos.

The camera includes the Photo Sphere feature introduced in Android 4.2. It produces 360 degree panoramas viewable on the phone or Google+ as if you were at the center of a sphere with the image printed on the inside. It’s a neat trick, but it requires a fair amount of patience and practice to capture the images effectively. Objects close to the camera are particularly vulnerable to stitching errors, so the best scenes are those with grand vistas but not a lot of foreground detail: think natural beauty more than interior shots. 

Another good reason to focus on the great outdoors is that if you’re shooting a Photo Sphere correctly, you’ll look a little ridiculous, so it’s nice if there aren’t too many people around. Google has a helpful demonstration video here but the basic idea is to pivot around the camera lens by holding the phone close to your face. You’re looking at five rotations to get a full sphere, so you’ll be dancing and squinting for a while. 

The Photo Sphere is saved as a distorted but otherwise conventional jpeg file that you can edit easily, but it can only be viewed in its 360 degree glory on the phone or on Google+ (or Google Maps). The web is full of beautiful examples of Photo Sphere images taken in exotic locales, but you can view our humble effort here. There are some more samples and information about Photosphere in our hands-on that we posted when the feature was first launched with the Nexus 4.