We shoot a specially designed chart in carefully controlled conditions and the resulting images are analysed using DXO Analyzer software to generate the data to produce the graphs below.
A high signal to noise ratio (SNR) indicates a cleaner and better quality image.
For more more details on how to interpret our test data, check out our full explanation of our noise and dynamic range tests.
JPEG signal to noise ratio
As we can see from this graph, the Canon IXUS 140's JPEG files contain a greater signal to noise ratios than those from the Pentax RZ18 at ISO 100-400, but are slightly weaker at ISO 800 and 1600. The Canon's JPEGs show weaker signal to noise ratios than the Nikon S5200's at every sensitivity setting except ISO 1600, and they're weaker than the Sony HX10V's at every sensitivity.
JPEG dynamic range
The Canon IXUS 140's JPEGs show comparatively better results for dynamic range, beating JPEGs from the Pentax RZ18 at every sensitivity setting, and those from the Sony HX10V at every sensitivity except ISO 100, where the scores are almost identical. The Canon's JPEGs show a greater dynamic range than JPEGs from the Nikon S5200 at ISO 200 and 400, but are weaker at ISO 800 and score the same at ISO 1600.