Maximum effective ISO is an estimate of the highest sensitivity at which a camera can capture excellent quality photos.
Cameras with higher effective ISO will be better choices for indoor photography, night shooting, and indoor sports photography, especially if you intend to make large prints.
You can learn more at our glossary entry.
Maximum effective ISO test data courtesy of DxO Mark.
G1X test data on DxO Mark MX-1 test data on DxO MarkLarge-sensor image quality. Sharp lens with useful zoom range. Tilt/swivel LCD. Twin dials. Smaller than competing interchangeable-lens cameras with a similar lens. Lots of photographer-friendly features.
Not as small as you might hope. Mediocre burst shooting and autofocus speed. Far too easy to accidentally change exposure compensation. Viewfinder is of surprisingly little use. Battery life could be better.
Good image quality for a compact camera in its class; Sharp, bright f/1.8-2.5 lens with 4x optical zoom; Cool retro-styled design with brass top and bottom plates; Tilting LCD; Exposure compensation dial; Speedy and accurate autofocus; Full HD video recording.
Image detail starts dropping off noticeably above ISO 800, and noise becomes problematic at ISO 3200 and beyond; Sluggish cycle times and burst performance; Issues with purple fringing in some shooting scenarios; Heavier and larger than other cameras in its class.
