Problem I've noticed concerning camera/ISO. Is it just me?
So, I've realised that when you change the ISO in manual mode, either because of a Sony policy to do so (this is my first sony phone) or because of a bug, the change in ISO is not reflected on your screen/viewfinder.
You have to wait until the photo has been taken before finding out whether the right iso was high/low enough. On samsung galaxy and lumia phones, when you change the iso the viewfinder adjusts to give you an idea of what the photo is going to look like in terms of exposure.