The HTC One X's built-in camera app has a comprehensive feature set for shooters who want to take some control over their camera's behavior, providing the ability to set parameters like ISO, white balance and exposure compensation. Users who thrive in point-and-shoot mode needn't feel left out, however. The HTC One X also has scene modes for portrait, macro and low light photography among others. Add in features like HDR and Panorama modes and you end up with most of the options you'd expect to find on an entry-level standalone camera.

Tap for focus and exposure

As is common on most smartphones these days, you can override the camera's autofocus selection by tapping an alternate area on the screen. You'll see a focus acquisition square appear onscreen temporarily as that portion of the image snaps into focus. On the One X, this focus tap biases exposure as well, and the camera will attempt to expose from the same area. Below are examples of exposure adjustments based on the location of the screen tap (shown in green).

With a tap on the building wall, the camera uses it to set both focus and exposure.
Tapping on a darker object, like the parked car in shadow, leads to a brighter overall exposure. The difference in focus is unnoticeable because depth-of-field is effectively infinite.

Rather unhelpfully though - and in contrast to the iPhone - there is no built-in way to manually lock either focus or exposure. Should you wish to recompose the image, the camera will automatically reacquire both focus and exposure.

Shooting Parameters

An impressively wide range of camera settings can be adjusted by tapping the Settings icon. While the camera's lens has a fixed aperture of F/2.0, experienced users can adjust scene brightness with exposure compensation, manually choose an ISO sensitivity and select a white balance preset.

You can customize the camera's behavior by tapping the Settings icon.

Yet even novice shooters can benefit from traditional standalone camera features offered here like face detection -  to automatically lock focus on a portrait subject - and Auto smile capture, which automatically fires the shutter when your subject smiles. A self-timer can also be set for up to 10 seconds. By default, the camera is set to capture 16:9 format still images. You can change that in the Settings menu to a standard 4:3 still image ratio.

You can adjust settings for exposure, contrast, saturation and sharpening...
...choose a sensitivity level up to ISO 800...
...select a white balance preset...
...enable face detection, geo-tagging and choose either a 4:3 or 16:9 image ratio.

Manual ISO

In Auto ISO mode, the camera selects from a range of ISO 100-1238. You can also manually select an ISO of 100, 200, 400 or 800. In a poorly conceived design though, you have no shutter speed indication available to guide your choice of ISO sensitivity. As a result, in a low-light situation you can easily set an ISO that drops the shutter speed to the point where you'll get a blurry shot due to camera shake. And you have no way of knowing the shutter speed is too slow until you review the image at 100%. We'd much prefer to see the camera's chosen shutter speed onscreen, or at the very least see a warning icon whenever the shutter speed falls below the 1/effective focal length standard.

As it stands there is very little practical benefit to manually setting ISO other than perhaps indirectly raising the shutter speed when trying to capture moving subjects in good lighting conditions.

HDR mode

The One X offers a multi-shot HDR mode intended to maintain highlight and shadow detail in high-contrast scenes. When activated via the camera app's Scene mode menu, a single shutter button press allows the camera to fire three consecutive shots, each at a different exposure. The shots are then automatically merged into a final image, combining elements from the over and underexposed frames to render highlight and shadow detail.

HDR off
100% crop
100% crop

In the backlit examples above, the AF point was manually set on the restaurant sign. In single-shot mode the camera meters the scene to preserve detail in the background, leading to a dark subject. When set to HDR mode, the resulting exposures are blended to include greater shadow detail and a better exposed subject.

The results are not perfect, with color channel clipping in the glass awning above the sign. In the 100% crops, artifacts are visible along high contrast edges. And because wind was moving the leaves between exposures, some ghosting is evident there as well.

The processing time required to produce the final image is fairly brief, necessitating a four second delay from the time you press the shutter button until you can take another picture.

Panorama mode

Android's Ice Cream Sandwich introduced an automated panorama mode that stitches individual images together on the fly. On the HTC One X, this results in a 9160 x 2265 wide image file. Capturing a panorama is a straightforward process complete with visual aids to help you keep the images level with the horizon.

With the panorama option selected in the Scene mode menu, you're presented with an onscreen level gauge (that is sadly unavailable in any other shooting mode) so that you can begin with a straight horizon.

Press the shutter to capture the first image and begin panning either left or right. A floating image frame appears onscreen. This replaces the level gauge and is matched to the framing used in your initial image.

The camera provides a floating image border as a visual aid to keep the phone level. As you pan, the camera snaps successive images, each confirmed by a shutter sound. When five images are captured, the camera begins stitching them into a single image.

It's interesting to note that if you want to create 'partial' panoramas you can simply tap the cancel button at any time during your pan. Instead of deleting the images, the camera will stitch together whatever image data it has already captured.

Panoramas are easy to create, but you don't have to look too closely to spot obvious seams and stitching errors. Even at this reduced magnification view you can make out the unfinished cloning edit around the Space Needle.

Image quality does not suffer noticeably by comparison to standard images from the One X, but as you can see in the image above, the stitching process is not perfect. In even slightly windy conditions - not uncommon when shooting from heights - that make it difficult to hold the phone absolutely steady for the entire pan, we regularly spotted imperfections both less and more severe than the example shown here.