Full review
Few cameras can justifiably claim to be as important as the long-running PowerShot G series. Canon's mature line of high-end pocket snappers has a well-earned reputation for flexibility, performance and image quality.
This is the second PowerShot G this year, and Canon has wisely kept spring's G1 X on sale, with the G15 sitting beside it. As their names suggest, they share many common features, but while the G15 is a less advanced option, it has a few enticing enhancements all of its own. That said, at £529 it does feel a little expensive when compared to its closest rivals -- including the G1 X.
Features
The G15 and G1 X look very alike. They both have sturdy, slightly retro bodies with a decent handgrip and generous range of hardware controls. The G15 benefits from a minor redesign with the shooting selector and exposure compensation dials offset from one another. On the G1 X, the exposure compensation wheel surrounds the mode selector, but the new orientation means that you can simultaneously switch between, say, shutter and aperture priority using your forefinger and exposure compensation using your thumb, and find your preferred shooting setting more quickly.
To the rear the layout matches the G1 X. In the G15 though, the screen is fixed, so you can't fold it out to unusual angles in order to capture trickily-placed subjects the way you can with the G1 X.
Around the front the G15 sports a lens equivalent to 28-140mm on a 35mm camera, which offers a greater range than the 28-112mm lens on the G1 X. The G15 delivers a 5x zoom where the G1 X delivers only 4x.
Much of the improvement can be explained, however, by the smaller sensor in the G15, which in turn supports a lower resolution. The G1 X has a 14.3-megapixel sensor delivering images of 4,352x3,264 pixels. In the G15 it's a 12.1-megapixel chip putting out 4,000x3,000 pixels at the highest setting.
The G1 X, then, certainly offers the better deal in this respect, and even though the zoom doesn't extend as far, those extra pixels allow you to crop more tightly while retaining a larger image to compensate.
The G15 is in many ways the more exciting camera in everyday use though, on account of its bright f/1.8 maximum aperture at wide-angle and f/2.8 at full telephoto, each of which afford great flexibility when it comes to keeping just a small portion of your image in focus and thus directing your viewer's eye. With the G1 X, maximum aperture ranges from f/2.8 to f/5.8.
Despite this, for anyone who spends more of their time working in shutter than aperture priority mode, the G1 X may yet be the better bet. With a maximum exposure time of 60 seconds it offers great nighttime potential in comparison to the G15's cap of 15 seconds.
That's where the main differences lie, and in most other respects the two are closely matched. They share an maximum sensitivity of ISO 12,800 with compensation of +/-3.0EV in 1/3 stop increments, and like the Samsung EX2F and Panasonic Lumix DMC-LX7, they each have a built-in physical neutral density filter.
Stills performance
The image below demonstrates perfectly how the impressive maximum aperture can be put to good use, for while the insect's back and closest legs are sharply focused, the legs that move away from the camera, and the end of its antennae are de-focused, despite being slightly less than an inch from the point of focus.
Macro performance is consistently strong, with fine details such as the fibres on the sweet chestnuts below accurately rendered, and a sharp falloff in the level of focus outside of the main subject area setting the surroundings in a beautiful creamy blur.
I performed my tests on a bright, cloud free day, and the G15 put the incoming light to great use. Colours were punchy in all cases, and skies were particularly satisfying. Blues and greens were bright and in all cases the captured tones accurately reproduced the original subjects.
Autumnal reds and browns were faithfully reproduced, and fine detail such as sunlight catching on a cobweb was clear in the finished result, even under extreme conditions.
In the image below, I was shooting directly towards the sun, which is flaring between two leaves at the centre of the frame. While you'd not expect the leaves to be completely silhouetted -- as the sun is able to pass through them -- you might expect a darker stem. Here though, the G15 has retained its original colours, and the cobwebs to the upper left corner are cleanly picked out. Furthermore, the sky has not been bleached out, nor the surrounding foliage rendered as deep shadow through excessive compensation.
Focus remained sharp right into the corners of the frame and there was very little difference between the level of detail rendered there and at the centre. This indicates excellent performance on the part of lens, which would need to bend the light at the edge and allow it to pass straight through the centre, while still directing everything to the same point on the sensor.
Low light performance was also good, and although it's possible to see some degradation within the image when zoomed to 100 per cent, frames exposed at ISO 800 retained an extremely high level of detail. Complex textures such as the cat's fur in the image below were cleanly recorded. I'd have no hesitation in printing and publishing these images online at their full-size, or cropping them lightly, as you only really notice any flaws when you examine the cat's whiskers at close quarters.
Still life test
I would usually look to perform the still life test using a camera's automatic settings, so it can make up its own mind about how best to capture the scene, but I switched the G15 to aperture priority and set the aperture itself to f/8. This was because in auto mode it self-selected an aperture of between f/2.0 and f/2.8 depending on the level of available light, thus shortening the depth of field. It also locked off the flash, so I was unable to force it to fire for the third shot.
Under studio lights, the G15 produced an extremely balanced and accurate result. Colours were true to the originals and textures were strong. When switching to ambient light or using the on-board flash however, there was a significant degradation in the result.
Under ambient light, the G15 quadrupled the sensitivity from ISO 400 to ISO 1,600, which naturally introduced a higher degree of noise than had been evident under studio lights. It was extremely well controlled however, and did little to spoil the finished result. Flat areas remained largely smooth, and although some of the textures were dulled, the speckling in those patches was remarkably light. Much of the lettering on the miniature spirit bottle remained legible (it's often lost by other cameras), but colours, on the whole, showed less fidelity than under the studio lights, with some brighter tones a little bleached.
The most disappointing result was that which it achieved when using the on-board flash. Although it enabled the G15 to reduce its sensitivity to ISO 320, it resulted in some harsh shadows and a significant fall-off in the level of illumination at the edges of the frame.
Video performance
As you'd expect from its stills performance, the G15 produces some pretty punchy video. I conducted my video tests at the same time as shooting my stills, and the rich autumnal colours once again shone through.
It had no trouble with fine details or rapidly changing scenes, such as woodland filmed while walking. Compensation for changes in the distance between the subject and lens was smoothly accommodated. The same was true of balancing out changes in the available incoming light, with the G15 making each adjustment swiftly, gracefully and without any stepping.
There's a dedicated movie mode on the shooting selector dial, or you can start filming directly in any of the regular stills modes by pressing the video button on the back of the case.
The optical zoom remains live when filming, and its movements are only very faintly audible on the soundtrack. There's also a wind-cut option that should minimise the effect of an ambient breeze on the recording, although even with this active there was still evidence of wind on some of my footage.
Full HD movies are captured at 1,920x1,080, 24fps, but you can step this down to 1,280x720 at 30fps if you need. Should the need ever arise, you can step it down further still to 640x480 or 320x240, at which point high shutter speeds of 120fps and 240fps come in to play, allowing you to capture action in super slow motion when replayed at regular frame rates.
Conclusion
Canon was right to keep the PowerShot G1 X in play when it shipped the G15, as despite their common heritage they're fairly dissimilar cameras.
Over time, when its own price falls, the G15 will become a G1 X for those who can't quite afford the real thing, as it lacks some of the most tempting features such as the larger sensor and articulated screen.
At the moment, though, as the new kid on the digital block, it's still rather expensive, and that makes the G1X the better deal, although the G15's maximum aperture is still very tempting and the reworked top plate is a boon.
The trouble is, in many places it's similarly undercut by the Samsung EX2F, and that's where the real competition lies. It has a fractionally higher resolution on the same size sensor, but improves on the maximum aperture (it's f/1.4 on the EX2F) and has both a fold-out screen and built-in Wi-Fi, all of which greatly enhances its appeal.
The G15 is a good, solid camera, but not the best you can buy. Over time, though, as its price inevitably falls, the proverbial measure of bang to buck will work ever more in its favour.