>>3975738sounds like a good proposed setup to me then. I have done some astro with the 12-40 as well with a cheap tripod. Olympus does have one really useful feature for astro/night light shots: Live Composite and Live Bulb/Time. I dont think any other company has something comparable yet. Live Composite for "painting" with light in the dark, and Live Bulb for watching the exposure develop and letting you see when it's exposed how you want. They're a bit finicky to learn to use, but way superior to doing it without.
I don't know about the samyang but I take my em5-ii and 12-40 out in rain and snow fairly often. I've gotten the whole thing soaked in downpours multiple times with no problems after, although I try to limit how often that happens.
