Well there is a lot to be said about landscape photography and the lenses to go with it.
IMHO it very much depend on what you want with your landscape images and how you like to shoot.
You will often hear the famous mantra:
Quote: landscape = ultra Wide angle
(14-24mm in 35mm terms), but it is not really true.
The range can be excellent for landscapes:
(nikon D3 and nikkor 14-24/2.8 @14mm)
But it also has an amazing ability to include everything adn that is not necessarily a good thing, at least to me landscapes is for a large part about simplicity, shape, light and composition.
The simplicity bit in particular is very difficult with ultra wide angle and requires a lot of work.
In my personal experience the best landscape lens is one that has a focal length or range of focal length that works well with how one see things. A lens that makes you "connect" with your surroundings.
Formost people these focal lengths are somwhat longer... For me personally I resonate really really well with the the regular wide angle range of 28-35mm in 35mm terms or 18 - 24mm range on APS-C, with my sweetspot in the middle of the range.
An example from the K-7 and DA21ltd, from a trip to Arches NP:
Now the long normal to short tele range is another often overlooked range.
that is extremely useful for landscape photography, especially when working in areas that are very large, It provides a sweet balance between forground and background elements andhelts retaining simplicity and balanced compositions
Here an example from theFA43ltd mounted on the K-7 from a trip to Nerlerit Inaat:
The tele range should not be forgotten either, It can be highly efficient as a landscape too., either to compress huge scenes in to simple and efficient compositions as in this example shot at 135mm on a nikon D3 at the Ilulissat Icefiord:
The telerange is extremely useful to pick out details, shapes, textures and colour in landscape settings,asseen in thisveryrecent sample shot with theFA77 on a k-7 in Ittoqqortoormiit Fiord:
Above images may not be perfect samples, but theywere what I was able to quickly find in my online galleries.
What really matters when selecting lenses in these ranges is their performance and I tend to look primarily at the lens renderings
Renderings is to me how the lens "draws" the image to the sensor.
As I print large and have clients looking for largish prints I tend to look at how they render when stopped well down, as I need it to get sufficient DOF.
Next comes the middle range of f5.6-f8 and finally the larger than f5.6 range.
Generally lenses with good contrast (micro contrast in particular), colour accuracy and tonality are preferred.
Resolution is another important thing to look at, you want a lens that is sharp enough, but it does not have to be razor sharp wide open IMHO.
How the lens handles bright lightsources in the frame is very important too. Occantionally you want the sun or orther bright light sources in the frame and just outside the frame.
Primes tend to do better than zooms here. As an example The DA*16-50 is a particular poor lens in this regard, below is an example from teh DA*16-50 on the K-7 of what I do not want from a landscape lens:
Bottom line is that there are a lot of excellent lenses out there for landscape photography, IMHO primes are generally preferred IQ wise:
Thus any of the limiteds, the Zeiss ZK range, the DA14, A and FA*24 will all be excellent landscape primes As will likely a whole host of M42 and other K, M, A, F and FA lenses.
The lenses that stands out to me is the DA21 and FA43 though, they are without a doubt my most used lenses for landscapes.
A long winded reply but hopefully it made sense.