The previously rumored NiSi 15mm f/4 wide-angle manual focus full-frame mirrorless lens is now officially announced and available for pre-order (NiSi products are also sold at  Amazon, and B&H): NiSi 15mm f/4 lens specifications: Lens design: MTF charts: Additional pictures: NiSi 15mm f/4 lens by NikonRumors No related posts.