Hey, I want to start out with night sky photography. I haven't done much expect the usual moon and star shot (nothing to show off so far) and want to go a bit more into that direction. My steep rise in interest results from a trip to Tromso, Norway in the end of February, where I hope to catch and photograph some northern lights. I know, the time frame for practicing isn't that long, but who doesn't love a challenge... So, here is my problem: I do own the Oly 12-40 which I plan on using at the long end at f2.8. I am a bit afraid, however, that especially for the northern lights, f2.8 would result in a too long exposure time or to high ISO. tflovik here on the forum advised me to start out with 8sec, f2.8 and ISO1600. What bothers me a bit about that is ISO1600, even on my E-M5. That's where my thoughts about temporarily getting a new/used lens come in. The initial price isn't that important, as I plan on selling the lens after the trip to Tromso. Unfortunately, there is no lens rental for m4/3 stuff here in Germany. Otherwise, this would have solved my problem. These are the lenses with pros and cons, I am considering: SLRMagic NOKTRON 12mm f1.6 + f1.6 + manual focus with infinity position + cheaper than the Oly 12mm f2.0 - sharp enough at the edges at f1.6 for landscape/night sky? - probably need to buy new as there is currently only one overpriced one at ebay at the moment - hard to sell afterwards? Olympus 12mm f2.0 + f2.0 + manual focus with infinity position + probably not that though to sell afterwards +/- ok prices on ebay - "only" one stop better than the 12-40 I already have Olympus 12-40 f2.8 + I already own the lens + manual infinity focus thing again - f2.8 What are your thoughts? Have you used any of these lenses for the task? Is there a lens I missed in the wide angle lineup? To even further complicate the matter: I also own the Pana 20mm f1.7 which I probably will also use. F1.7 is exactly what I am looking for, however, 20mm might be to narrow and the by-wire manual focusing had me getting into troubles when focusing in the night before.