Hi all. I need to buy a lens in the next day or two. It will be on a GH3 on a tripod to cover wide to medium wide shots on a dance floor at wedding receptions. Would like decent auto focus and low light handling. Trying to keep price under $500. Trying to decide between Panny 25mm 1.4, 20mm 1.7 (seems the auto focus is loud and slow) and 14mm 2.5. Would appreciate any input. Thanks!