E-PM2 + 12mm Samyang + Remote Trigger for Astrophotography?

I'm going to say you will want a 12mm lens for real widefield astro and night sky photography, otherwise, you may well not fit what you had intended to in your frame. I struggled with my 12mm F/2 not being wide enough. You can stitch photos later if you want more real estate but it's not ideal for every situation. This is actually 2 12mm frames... I've had to do perspective and distortion correction in post processing and the perspective is still not really correct if you look at the building in the background.

Your going to end up with a whole heap of perspective distortion and the majority of your shots will look as if you took them with a fish eye if you start trying to do night sky photography with a 17mm lens.

The second shot below is 3 frames of the Milky Way with my 9-18, it still really isn't wide enough nor is it really fast enough to properly expose the milky way. You can see it just faintly... I live in an area as you can see where dark sky nights are a regularity. I wouldn't live without at least a 12mm lens at F/2. It is my most useful and versatile lens.

The 12/2 can be used for just about everything even close crop portraits, just use the portrait orientation on your camera and get closer if you want more of someone in the frame for isolation, or just get closer in general.

One of the biggest misconception with lenses bordering on being ultra wide angle lenses is that you have to take a shot from 40ft away and get it all in, this is wrong on so many levels I don't even know where to begin.

Just get closer.... My 12mm F/2 is the most versatile lens I have. I have the 20mm F/1.7 as you will see from my gear list, I honestly almost always feel stuck in no mans land with a standard lens in terms of modern photography.

There are too many people on this forum that have silverfish and moths in their closets and enjoy the fact that they have silver fish and moths in their closets. 35mm is really no mans land, it's not wide nor is it long, and you will find yourself either stuck with "horse blinker" photos, or stuck in a situation where your lens is not wide enough, or long enough.

I honestly hate standard lenses, the last 4 shots in the list are from my 20mm F/1.7. Actually finding a good use for a standard lens for me is like finding a needle in a haystack. There is so much more to the world than defining yourself by 50 year old camera standards for "normal" lenses and that "standard" is not relevant to modern photography.

12/2

9-18

12/2

20/1.7

20/1.7

20/1.7

20/1.7

You can do so much better if you just open your mind up to the possibilities that the world need not exist in a 35mm frame.