I'm freaking out a bit because I have this trip to Iceland in like two weeks and I still havent settled on a wide angle for my SL2. Ive been shooting with the 35mm Summicron mostly but I need something way wider for the landscapes and maybe some aurora stuff if I get lucky. I spent all night reading reviews and honestly Im just more confused now lol. Some people swear by the 21mm Super-Elmar-M with an adapter but then others say the edges look like mush on the SL2 sensor because of the glass thickness or whatever. Then there is the Panasonic 16-35mm Pro which is way cheaper and native L-mount but I keep seeing mixed stuff about whether it actually resolves enough detail for that 47mp sensor... like is it gonna look soft compared to Leica glass?

I really need something top tier that wont make me regret the purchase when I get home and see the files on a big screen. I dont want to spend all this money on a trip and have blurry corners.

Here is what I am looking for:

• native L mount preferred but open to M if it really works well
• budget is around 5000 dollars but obviously less is better
• needs to be sharp wide open for night shots
• not incredibly heavy because I am hiking a lot

Should I just bite the bullet and get the 21mm APO-Summicron-SL? Its so expensive and heavy but maybe its the only real choice? Or is there a Sigma option I missed that actually holds up? I really need to order this by Monday to get it in time...