To compare real-life performance when zoomed-out, I shot this scene with the Canon PowerShot A2300 and the PowerShot A3400 IS within a few moments of each other using their best quality 16 Megapixel resolution.The lenses on both cameras were set to an equivalent field of view and both were set to Program auto exposure mode.
The ISO sensitivity was manually set to 100 ISO on each camera.
The image above was taken with the Canon PowerShot A2300. The lens was set to its maximum wide angle position at 5mm to provide an equivalent field of view to the 5-25mm lens on the PowerShot A3400 IS. In Program auto mode the camera metered an exposure of 1/250 at f7.9. The original JPEG image size was 4.09MB. The crops are taken from the areas marked with red rectangles and presented here at 100%.
The A2300 doesn’t have image stabilisation, but the A3400 IS does and for this tripod-based test it was disabled, while i-Contrast was left in the default off position on both cameras. Before I analyse the 100 percent crops I just want to briefly talk about the aperture selected by both cameras and its effect on image quality. Both the A2300 and the A3400 IS selected an aperture of f7.9 in Program auto mode (implying the choice of just two aperture settings). An initial test shot I made with the A2300 selected an aperture of f2.8, but subsequently the A2300 steadfastly refused to budge from f7.9. The A3400 IS selected f7.9 for every shot, so lacking a pair of f2.8 shots for comparison and with no aperture priority mode to force a wider aperture, for a fair comparison I’ve compared crops from the f7.9 exposures. But it’s also only fair to point out that the quality of the single f2.8 exposure from the A2300 is visibly better than these f7.9 crops which suffer noticeably from diffraction.
Aside from the diffraction issue the most noticeable thing about these crops is the low level of detail and the clumpiness of the pixels. All of these crops look quite heavily processed and there’s quite a noticeable degree of texture in areas of flat colour. In the first crop a lot of the fine detail in the chapel walls and the foregound has been obscured by this clumpiness.
In the second crop the processing doesn’t to a lot for the detail in the lighthouse and what should be a distinct thin white rectangular column is a bit of an indistinct blob. The detail in the foreground of this crop is a little better though and you can make out the edges of the window frames. Once again though the finer detail in the roofs is obscured by the clumpy fug. The third crop from the edge of the frame fares no better, but no worse either. Here I’d be looking for evidence of lens defects but the lack of detail recorded by the sensor makes it difficult to determine if the lens quality deteriorates towards the edge of the frame. From what can be seen though, the detail here looks consistent with crops from nearer the centre of the frame.
The last crop from close to centre of the frame is the best in terms of definition with reasonably well defined edge detail, I’d hesitate to call it sharp, though, as once again the clumpiness makes everthing appear as it was viewed through a dirty window. It’s worth pointing out that at typical screen sizes you’re unlikely to notice this pixel clumping and loss of detail, but if you plan on making large prints, or radically cropping your shots it could become an issue.
These results from the Canon PowerShot A2300’s 16 Megapixel CCD sensor are a little disappointing, particularly as this sensor is used in the entire 2012 PowerShot A line up. Having said that the crops from the PowerShot A3400 IS, which shares the same 16 Megapixel sensor look significantly better than those from the A2300. They still look very processed and there’s the same pixel clumping, but not to the same degree and the A3400 IS crops show better detail as a result with sharper, more clearly defined edges.
To compare noise levels under real-life conditions I shot this scene with the Canon PowerShot A2300 and PowerShot A3400 IS within a few moments of each other using their best 16 Megapixel resolution at each of their ISO sensitivity settings.
The cameras were set to Program auto exposure mode, the lenses were set to the same field of view and the ISO sensitivity was set manually.
The above shot was taken with the Canon PowerShot A2300. The lens was set to its maximum 5mm wide angle position which provides a similar field of view to the 5-25mm lens on the PowerShot A3400 IS. For these tests the camera was placed on a tripod. The A2300 doesn’t have image stabilisation, but the A3400 IS does and for this test it was disabled. i-Contrast was left in the default off position on both cameras. In Program auto mode the A2300 chose an exposure of 1/5 at f2.8 at 100 ISO
As we saw in the outdoors test, even at the base 100 ISO sensitivity setting there’s visible noise in the 100 percent crop from the PowerShot A2300. As a result the edges of the memorial frame already look a bit indistinct and there’s a coarse granularity to the flat colour of the cream wall. There’s also a distinct purple patchiness to parts of the image which varies from crop to crop.
At 200 ISO, there’s a marginal increase in the noise levels, but at anything less that 100 percent view you’d be hard pressed to tell the difference between 100 and 200 ISO. At 400 ISO, though, detail is beginning to break up and the horizontal highlight running along the top of the memorial above the text area is spreading beyond its bounds. This is still a good enough result to get by at less than 100 percent view though.
At 800 ISO things take a dramatic downturn. Both the noise and processing to reduce it have ratcheted up and the result is a corresponding worsening in image quality with all but the coarsest detail losing out in consequence. You don’t have to be pixel peeping at 100 percent view to see a difference in quality between the 100 and 800 ISO images, though this and the 1600 ISO shot are fine for web viewing at small sizes, they’re not suitable for everyday shooting and are best reserved for ‘must have’ low light shooting. The Low light scene mode produces slightly better results at automatically selected high ISO settings, but at a reduced 4 Megapixel resolution.
Compared with the PowerShot A3400 IS there’s not a lot in it – as indeed you’d expect from cameras sporting the same sensor. The crops may look qualitatively a little different but the degree of noise and processing artefacts is about the same. As in the outdoor test the PowerShot A3400 IS crops are slightly sharper, which reveals better detail in the 100 and 200 ISO crops, but once you move up the ISO range it translates into an unpleasant harshness. You can’t see any more detail in the 800 ISO crop from the A3400 IS than the A2300 one – the clumpiness is just harder edged.