You asked
Leica super vario elmar sl 16 35mm f 3 5 4 5 asph vs panasonic 16 35mm f 4?
I don't have a page for the Panasonic 16-35mm f/4 on this site, so I can't compare the two without guessing at its specs.
The Leica Super-Vario-Elmar-SL is a full frame L-Mount zoom at 16-35mm, f/3.5-4.5, with autofocus and no stabilisation. It gets darker as you zoom in. Its full catalogue page lists the Leica SL bodies and several Panasonic Lumix S-series bodies it fits.
For landscapes, the aperture difference between f/3.5-4.5 and f/4 matters less than you might think, since you'll usually shoot around f/8 to f/11 anyway. The Landscape guide explains why a wide zoom suits that kind of work.
Written by Claude from this site's pages.