What is the best wide-angle landscape lens for the Sony a7IV?

Honestly, lens prices these days are just disappointing. I spent a lot of time pixel peeping the Sony FE 16-35mm f/2.8 GM II and unfortunately, the edge-to-edge resolution at 16mm just wasnt as good as expected given that massive price jump. Its light, sure, but you are definitely paying a premium for the badge. I had issues with the flare control on it too when the sun hits at a weird angle... not ideal for those long Icelandic golden hours when you want that perfect sunstar. The Sigma 14-24mm f/2.8 DG DN Art is technically superior for raw sharpness, but man, that bulbous front element is a huge pain in the neck. I found it nearly impossible to keep clean near waterfalls because you cant use a standard screw-on filter to protect the glass. If you go this route, you have to buy a bulky external filter holder system which just adds more weight to your pack. Its frustrating because the glass is brilliant, but the design is a bit of a nightmare for wet environments. Since youre in Oregon, you should be able to get the Sony FE 20mm f/1.8 G delivered in a few days. Tbh, its actually sharper than both those zooms and way better for astro if the Aurora shows up. If you really need the zoom range though, just go with the Sigma and accept the weight. Quick tip: Buy a dedicated rain cover for the camera body. Even weather-sealed gear can fail when that Icelandic wind starts driving rain sideways into the ports. Youll be fine though, its gonna be an epic trip regardless of which glass you pick.

To answer you directly, I really dont think the GM II is worth the extra 700 bucks for what you are doing. I was in your exact shoes last year before a trip to the North Atlantic and I ended up going with the Sony FE 20mm f/1.8 G instead. Honestly, I have been so satisfied with that choice because it handles the harsh Icelandic-style weather perfectly. I was standing in the thick mist of some massive waterfalls for hours and the weather sealing held up without a single hiccup. It felt rock solid. Here is why I think you should consider a prime like that over those bulky zooms:

• Sharpness is basically unbeatable, even compared to the Sony FE 16-35mm f/2.8 GM II
• Uses 67mm filters... way easier than messing with bulky filter holders in the freezing wind
• f/1.8 is a total game changer if the Aurora shows up and you need that extra light
• Super light, so your neck wont be screaming at you by day three I know you mentioned the Sigma 14-24mm f/2.8 DG DN Art too, but that exposed front element is just a magnet for rain droplets and salt spray. It makes cleaning it a constant nightmare in the field. With the 20mm, I just felt safer and more relaxed. When I finally saw the photos on my monitor back home, I was blown away by the clarity in the textures of the black sand and moss. It is just a reliable tool that works well without breaking your budget.

Ngl, go for the Sigma 14-24mm f/2.8 Art! Seriously amazing glass. It is an absolute beast for sharpness and the colors are just fantastic. To handle the filter issue, definitely look into a rear filter kit instead of those huge, expensive front systems. Its way easier for travel! I used a handy cart sharer to bundle my gear order and keep it all organized before my last flight. You are gonna save a ton of money and still get pro-level shots in Iceland! The extra $700 is way better spent on your actual trip than on a Sony badge... dont even hesitate.