How to Use Dual Native ISO on the Panasonic EVA1
Native ISO is a fairly simple technical term that becomes complicated very quickly when put into practice. Put simply, native ISO is the highest ISO that doesn’t require any signal amplification. Add more voltage to the sensor circuit, and you get a brighter image, but with more noise. Knowing exactly where that Native ISO falls without any help from the manufacturer is a pain, but it is a pain which Panasonic has spared us from with the EVA1. Even better, they gave us two natives.
Panasonic has been pretty tight-lipped, but we can roughly surmise that Dual ISO works by running two separate circuits on the same sensor, each tuned for a different sensitivity. This matters to you, the operator, because it means that you can no longer simply roll from ISO 100 to ISO 25,600 in one go. Practically speaking, what you have now is essentially two separate shooting modes - low ISO mode and high ISO mode.
To toggle between them, the first step is to go to Menu > Camera Settings > EI. Here you will find a setting called ISO select, which lets you choose your base (native) ISO. In 800 Base, your available range is from 200 to 2,000. But of course if you need to maximize your low-light, you will shoot in 2500 Base, where your options range from1,000 to 25,600 ISO. You can expect that both native ISOs will perform equally admirably, and in both modes you can push the sensor reasonably far while still obtaining great results. The only question is which Base mode you need.