Venus Optics has been slowly releasing the four lenses it teased back in April of 2018. We saw the 10-18mm f/4.5-5.6 for Sony E-Mount in October, the 100mm 2x Macro for full-frame DSLRs in June, and the 17mm f/4 Zero-D for Fuji GFX earlier this month. Today, they’re officially releasing the last lens: the Laowa 4mm f/2.8 Circular Fisheye for Micro Four Thirds systems. This 8mm equivalent fisheye lens’ party trick is the fact that it can actually see behind…