EM-5 Low ISO, there is a RAW difference
There is a RAW difference between ISO 200 and low ISO on the E-M5. At least according to this website http://www.guillermoluijk.com/article/em5isolow/ According to his measurement the RAW file is at ISO 160 whatever that means both theoretically and practically. I would expect a tiny bit cleaner black and the same headroom as ISO 200 if you "underexpose" by 2/3 f/stop.-- hide signature --
In short, it seems that LOW ISO on the E-M5 is like ISO 250 underexposed by one stop.
How do you draw that conclusion?
If the RAW is different at camera ISO 200 and camera ISO Low (measured to ISO 160), I would guess that ISO 250 is equal to ISO 200 (If there is no difference at RAW files between ISO 200 and ISO 250 underexposed 1/3 f/stop).