Canon PowerShot G1 X Mark II review – Noise, resolution and sensitivity
The drop in effective pixel resolution hasn’t had a detrimental effect in the level of detail the 1.5in-type CMOS sensor can resolve. Shooting in the default 3:2 aspect (12.8 million pixels), the camera can just about resolve 26 lines per millimetre (lpmm), which is the same readout as when we tested the original G1 X. Detail drops off slightly to 24lpmm at ISO 400, but even at ISO 6400 the chip resolves detail to around 20lpmm, which is impressive given its compact status. However, detail drops off considerably at ISO 12,800, so this sensitivity setting should be avoided.
An inspection of high ISO JPEG images revealed the importance of shooting in raw. Although the sharpening applied to JPEGs isn’t overly aggressive, shots at higher sensitivities are smoothed out so fine detail is compromised. To test the claimed improved light-gathering capability, we compared JPEGs and raw files of the same scene taken on the original G1 X and the Mark II. Our comparison revealed truth in the claim, with the G1 X Mark II showing fractionally less luminance noise in JPEG and raw files at ISO 6400 and 12,800 – most obviously in the darkest shadows.
These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured with the lens set to an equivalent setting of 50mm . We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.
