Thank you for directing me to that forum. There is a lot of useful information there and I'm taking notes. It seems the advice are somewhat balanced for both Sigma and Rokinon with a little more in favor of the Rokinon.
They are both solid options. It actually depends on what you want, both have trade-offs.
Why did you advice going for the Rokinon?
Simply because i have it and i haven't tried the Sigma 16. It's cheap, wider, manual, fast, relatively small and not heavy as the sigma. But Chromatic aberrations are worse on the Samyang.
Manual focus is easy to use and you will need it anyway for astro.
Is it because, it will complement the kit 16-50mm lens that we already have, because the 12/2 is something I can use for landscape/astrophotography/northern lights? I'm just trying to understand. I also want the lens to be something I can use long term and not just for the northern lights trip.
I like the Samyang but i know the Sigma is a more versatile lens, because of the focal lenght and autofocus. Some people even use the Sigma for full body portraits. If you need a larger view of the scene make a panorama (i don't know if panoramas are possible with northern lights since they move faster than stars).
Do I need to get a shutter release button?
I've never shot the northern lights but i don't think so, the self timer should work OK. Probably if you are going to do startrails or time-lapse it could be worth. The Sony playmemories app can do this too, but you have to pay separate for those functions.
Do you have any recommendations for a good budget but sturdy travel tripod? I have a tripod already but it's too long it won't fit a checked-in luggage.
What's your budget? What's your current tripod to compare measures?
I was doing a lot of researches lately for a budget tripod, not for traveling overseas but for some hiking. I ended up buying a Manfrotto Element Big, there is a small version available.
Just my two cents. Good luck.
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