Color depth refers to the number of unique colors that a sensor can faithfully capture. Cameras with better color depth will demonstrate smoother transitions from one color to the next, and avoid "banding" in areas with subtle shading. (Blue skies are an example of where you might see color banding.)
More color depth is generally better, but you'll struggle to notice a difference between two cameras with less than 1 bit of difference. Color depth above 22 bits is considered excellent.
Want to learn more? Head over to our full glossary entry on color depth
Color depth test data courtesy of DxO Mark.A7R III test data on DxO Mark K-3 II test data on DxO Mark
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.A7R III test data on DxO Mark K-3 II test data on DxO Mark
Top-notch image quality; Spectacular detail from Pixel Shift Resolution; Better performance than K-3; Geotag images with no accessories; Great ergonomics in a compact body; Clever on-demand low-pass filtering; Broad sensitivity range; Large and bright viewfinder for an APS-C camera; Dual card slots
No built-in flash strobe; No wireless flash support out of the box; AstroTracer function can be finicky; AE Lock button is poorly located; Below-average battery life for a prosumer DSLR; Requires a different battery grip accessory than its predecessors
Fantastic image quality; Improved dynamic range over its predecessor; Very good high ISO performance; Much improved real-world AF performance; Class-leading burst rates, even with RAW; Improved 5-axis in-body image stabilization; Better 4K video quality; 1080/120fps video; Dual card slots; Significantly better battery life.
Expensive; Menus still confusing; UHS-II support only on one card slot; No optical low-pass filter means greater risk of moire; No built-in flash; Buffer clearing still slow despite UHS-II support.