Panasonic Lumix DMC-FZ2500 read noise vs ISO

The Panasonic Lumix DMC-FZ2500 was measured at 26 ISO settings from ISO 80 to ISO 25600. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (80) read noise is 0.54 DN, or 2.8 electrons at the sensor. From ISO 1250 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 12800 don't change analog gain (digital push). Full well at base ISO is about 20,770 electrons; unity gain is around ISO 420.