You can now preorder the new Laowa 15mm f/20 FE lens at Venuslens.net (Click here). This is yet the world fastest E-mount wide angle lens!
Bastian just posted the full lens review and the conclusion is:
When I first heard about this lens I thought it sounded almost too good to be true. But despite the few shortcomings this is in fact a pretty astonishing lens Laowa have put together. I also tend to think it is the most versatile ultra wide angle lens I have used so far: It lets me take crazy close up shots, I can use standard filters on it, build quality is top notch, the size makes it a lens I want to put in my bag and yes, it can also be used for astrophotography.