The Voigtlander 17.5mm f0.95 is a great lens to use in low light. Many Micro Four Thirds cameras have a considerable crop factor so you need very wide lenses to go with them. The 17.5mm on a GH3 is the equivalent of a 35mm lens and roughly a 50mm on a Blackmagic camera. Perfect lens to use along the Voigtlander 25mm f0.95.