Thanks for all the awesome comments, much appreciated 
Currently running a GTX 980 but just upgraded to a 4K monitor to try and push the visuals further, so I’ll likely upgrade my GPU soon as the 980 can’t handle the resolution
I will make a breakdown on a new scene soon Still figuring out new ways to approach creating the tree geometry!
The tree in that scene (duplicated about 30 times) has about 85K triangles, which is definitely a lot, but I have been experimenting more since then and can get a similar looking tree at about 35K tris. Keep in mind that I originally create these scenes for fun, without optimization in mind for games- since I get a lot of questions about performance, I’m working on creating a super optimized scene with a comparable amount of quality now. There were no LOD’s for the trees, and everything was dynamically lit- loads of room for improvement in performance! The trees in the background are simple SpeedTree billboards of the other tree model in the scene (that one has an extra LOD for super distant trees)- so they have very little cost!
The lighting setup is a dynamic skylight and a single directional light with a very low intensity- that’s it
Thank you I come from a music background actually, I didn’t go to college! Honestly everything is super simple in my scenes- it’s all about experimenting and trying again and again to get a better result.
I assure you it is 100% 3D, everything from the skydome to the landscapes (World Machine) to the distant trees (which if you look closely are all exactly the same billboard mesh- just duplicated many times). I’m not trying to fool anyone, this is purely for my own pursuit of realism in UE4! Again I’ll take it as a compliment that you think it is a composed photograph