The image above was taken with the Canon PowerShot G15. The camera was set to Aperture priority mode with the aperture set to f4 and the sensitivity was at 80 ISO. The PowerShot G15 metered an exposure of 1/125 at f4, which resulted in blown highlights in the sky and a histogram clipped on the right. In order to produce a correctly exposed result I adjusted exposure compensation by -2/3EV. Similarly the the Nikon Coolpix P7700 overexposed the scene and I adjusted its exposure by the same amount. This resulted in an exposure of 1/250 at f4 which most closely matched the result from the G15. The JPEG image file size was 5.69MB.

So, what do the crops tell us about the G15’s image quality? Overall they’re pretty good, though it’s a little disappointing that the G15’s Evaluative metering, which sets the exposure according the brightness of the overall scene, initially overexposed requiring nearly a stop of exposure compensation. Having said that the Coolpix P7700 made exactly the same error. Generally there’s a good level of detail in these crops, more than you’d see from a point and shoot compact with a 1/2.3in sensor, but don’t expect the sort of detail you’d get from a camera with a DSLR or CSC sized sensor, for that you’ll have to move up to something like the PowerShot G1 X.

The first crop looks a little soft on the fine detail, but there’s no evidence of noise or processing artifacts. In the second you can make out the lighthouse on its island, though it is a little blurry. Similarly the edge detail in the window frames in the foreground looks a little soft. The third crop from close to the frame edge is pretty good though. Once again it’s a tiny bit soft, but no more so that the other crops and there’s no evidence of chromatic aberration whatsoever.

The fourth and final crop is usually where you see a bit of an improvement in detail resolution and sharpness, and there is a slight improvement in the centre of the frame but not a massive difference. The remarkable consistency in these crops is down to the G15’s lens, which produces great results from the centre to the edge of the frame. The fine and edge detail is a little soft, although that’s something it may be possible to address if you shoow RAW and process the files yourself.

Compared with the Nikon Coolpix P7700 it looks to me very much like the Nikon crops are cleaner, sharper and show more detail than those from the G15. And I think this is more than just a question of processing. In all of the crops you can see more detail from the P7700 – the doors and windows in the chapel, the lighthouse and the bacony dividers in the final crop.

Check out my Canon G15 RAW results on the next page or see how these models compare at higher sensitivities in my Canon G15 Noise results.

The image above was taken with the Canon PowerShot G15. The camera was set to Aperture priority mode with the aperture set to f4 and the sensitivity was set to 80 ISO. The PowerShot G15 metered an exposure of 1/125 at f4, which resulted in blown highlights in the sky and a histogram clipped on the right. In order to produce a correctly exposed result I adjusted exposure compensation by -2/3EV. Similarly the the Nikon Coolpix P7700 overexposed the scene and I adjusted its exposure by the same amount. This resulted in an exposure of 1/250 at f4 which most closely matched the result from the G15. The RAW image file size was 15.4MB.

I processed both files in Adobe Camera RAW using identical settings: Sharpening at 70 / 0.5 / 36 / 10, Luminance and Colour Noise Reduction both set to zero, and the Process to 2012 with the Adobe Standard profile. To further reduce any distracting visual differences between the crops I also set custom white balance to 6000K and tint to 0. These settings were chosen to reveal the differences in sensor quality and isolate them from in-camera processing. The high degree of sharpening with a small radius enhances the finest details without causing undesirable artefacts, while the zero noise reduction unveils what’s really going on behind the scenes.

Just to note, at the time of writing you’ll need the ACR 7.3 Release Candidate update to process PowerShot G15 RAW files, which is available from labs.adobe.com.

Revealingly, these RAW crops show quite a bit more detail than the in-camera JPEGs on the previous page. They lack the softness of the G15’s JPEGs, or at least, the fine detail and edges in these crops is clearer and more distinct. These crops also look more grainy than the JPEGs, but what they show is that, if you shoot RAW and process your own files, there’s every chance of squeezing more detail from the G15’s sensor than you’ll get shooting with the best quality JPEG setting.

Compared with the RAW crops from the Nikon Coolpix P7700 processed in exactly the same way, there isn’t as much of a quality gap as with the JPEG crops. The Coolpix P7700 still has the edge, with crisper, sharper edges and superior fine detail resolution, and the G15 crops still look a little soft in comparison, but the difference isn’t nearly as noticeable. With these processing settings the P7700 crops also look grainier than those from the G15 and there’s clearly some chromatic aberration that’s being dealt with in-camera. But let’s take nothing away from the P7700 which produces very good in-camera JPEGs from RAW data that reveals a very capable sensor and lens.

Now, it’s time to examine their high ISO performance, starting with a JPEG comparison in my Canon G15 Noise results.

To compare noise levels under real-life conditions, I shot this scene with the Canon PowerShot G15 and the Nikon Coolpix P7700 within a few moments of each other using their best quality JPEG settings at each of their ISO sensitivity settings. I also shot this in RAW and you can see those results on the next page

The zoom on both cameras were set to their maximum wide angle, 6.1mm on the G15 and 6mm on the P7700, providing an approximately equivalent field of view.

Image stabilisation was disabled for this tripod-mounted test and all other settings were left on the defaults.

To compare RAW noise levels under real-life conditions, I shot this scene with the Canon PowerShot G15 and the Nikon Coolpix P7700 within a few moments of each other using their RAW modes at each of their ISO sensitivity settings.

The zoom on both cameras was set to their maximum wide angles, 6.1mm on the G15 and 6mm on the P7700, providing an approximately equivalent field of view.

Image stabilisation was disabled for this tripod-mounted test and all other settings were left on the defaults.