Hey everyone, I have a conundrum that I would love some advice on. I'm about to take a two month trip across the US, hitting all the big national parks and pretty much just seeking out the mountains. I will be in BC as well, maybe even Banff at some point. I've got a budget of $4000, and part of that will already be dedicated to getting a Canon 5DsR for ~$3100, leaving me with roughly $900-$1000 for a lens. I currently have an 80D with an EF-S 17-55 F2.8 IS USM, EF 50 f1.8 STM, and EF 70-300 f4-5.6 L. My passion is for landscape photography, but as a budding professional I know that I cannot simply jump into success in landscapes specifically and therefore would like to shoot portraits/weddings here soon. I have already decided on getting the 5DsR, now I just cant decide whether I want to try and get a used copy of the EF 24 f1.4L or a used copy of the 16-35 f4 L. Based on the research I have done so far, the 24mm has the ability to produce a much sharper image, obviously partly due to being a prime lens (sharpness is something I am going for paired with the 5DsR) and also has the ability to be a lens for astrophotography with that wide aperture. However, it does not have IS, and of course any other focal length than 24mm. The 16-35 f4 seems to be one of the best dedicated landscape lenses, with great overall sharpness, a focal range that is more than that of the 24mm, and has IS which would make handheld shooting easier. Most of the time I will be trying to use the 5DsR on a tripod, but since it will be my only professional body, there is a good chance I will use it handheld a lot. Though I will be doing everything I can to avoid motion blur due to the massive pixel count in photos. I'm interested in hearing anyone's thoughts on the matter, especially any experience related to the 5DsR with either of these two lenses.