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.E-PM2 test data on DxO Mark GM5 test data on DxO Mark
Cameras with longer battery life can take more photos before exhausting their batteries.
Special note: The measurement standard for battery life stipulates that if a camera has an internal flash, it must be used for 50% of photos taken. For this reason, comparisons of one camera with an internal flash to another without will not be comparable
Super compact and lightweight; Excellent image and print quality that rivals much more expensive CSCs and DSLRs; Solid low-light (high ISO) performance; Touchscreen LCD responsive and useful once you get used to it; Speedy and accurate AF on still subjects; Tons of advanced shooting features and customizing options.
Maddening menu system; No physical Mode dial; Motion AF not quite up to par; Mediocre HD video quality; No built-in flash (but a small external flash is included).
Great image quality for a tiny camera; Excellent high ISO for its class; Built-in EVF; Built-in hot-shoe; Improved ergonomics; Improved image quality for long exposures; Improved burst rate with hybrid shutter; 1080/60p video.
Slightly bigger than GM1 (but not by much); No built-in flash; Shallow buffers with RAW files; Dynamic range not quite as good as some competing models; Below average battery life.