You asked
Is the leica summilux m 35mm f 1 4 good for landscape?
Not really, not as my first pick. The Summilux-M 35mm f/1.4 is a fast, manual-focus prime for full frame Leica M bodies, and it's soft and glowing wide open. That suits people, street and low light far better than wide landscapes.
My landscape guide says you'll usually shoot between f/8 and f/11, often on a tripod, so a fast aperture doesn't help much there. What landscapes need is width. A wide zoom, around 16-35mm on full frame, gives you big skies and strong foregrounds, and a 35mm prime can't reach that. If you already shoot with a body like the Leica M11, this lens is a good everyday standard, just not the one I'd take up a ridge.
Written by Claude from this site's pages.