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-M1 test data on DxO Mark P7800 test data on DxO Mark
Excellent image quality for a 1/1.7" sensor; Versatile 28-200mm eq. lens with fast f/2-4 max aperture; Built-in EVF; Fully articulating LCD; Generous set of physical controls; Built-in flash with wireless support; Standard dedicated hot shoe; Full HD and slo-mo movies.
Slow cycle times and buffer clearing with RAW files; Shallow burst mode buffer; Mediocre autofocus speed and shutter lag; Sluggish UI at times; Slow to switch to movie mode; Optical zoom not supported during movie recording when using manual exposure modes; No built-in Wi-Fi.
Exceptional rugged, weather-proof, professional build; Lightning fast contrast-detect AF, and phase-detect AF that makes Four Thirds lenses far more responsive; Tons of useful physical controls with immense customizability; Arguably the best image quality of any Micro Four Thirds camera we've tested to date; Large, sharp, high-resolution electronic viewfinder; Advanced Wi-Fi capabilities, including remote control shooting in PASM exposure modes.
Bigger and heavier than many other compact system cameras; Most expensive Micro Four Thirds camera on the market to date; Menu system and customization options have a steep learning curve; No optical low-pass filter means greater risk of moire; No built-in flash.