I use a Nikon D610 with a selection of prime lenses (20mm, 28mm, 35mm, 50mm, 105mm). While I appreciate the versatility of zoom lenses, I find that I prefer the image quality of prime lenses and they tend to be more lightweight and compact unless you are carrying all of them at once! My most used focal lengths are 20mm, 35mm and 105mm. I use the Nikkor 20mm f1.8G for wide-angle landscapes and scene setting. The Sigma 35mm f1.4 Art provides a shallow depth of field to separate subject and background due to the wide aperture, but along with the 105mm f2.5 is also good for focusing in on details. If I was to take one lens with me on an expedition, I would take the Nikkor 28mm f2 AiS. It is one of the older manual focus lenses, but it has a rugged metal construction and excellent image quality.