Busted Normal Map - Sub Designer

StormyBA

I'm getting some really odd effects on my normal maps of late in Designer. I'm plugging in height maps generated in designer into the height > normal node and getting some very bitty quantising type effects going on. 

Any thoughts? have I done something odd in the settings? 

Froyok

Is your heightmap 16bits ?
The stepping you see here is called banding, and because of the lack of bit depth in the heightmap, the normal generation end-up like this (aka broken).