I have recently bought a E-M1 and 12-40mm f/2.8, 60mm f/2.8 Macro and 75mm f/1.8. I'm wondering whether I should add a 12mm f/2.0 ahead of a trip I'm going on next month to Chile... I'm expecting to take a lot of landscapes and would like to do some astrophotography... do you think that the 12-40mm f/2.8 @ 12mm f/2.8 will be ok? There doesn't appear to be many wide fast options. The Panasonic 15mm f/1.7 looks interesting but not available yet.