I have the 21 Zeiss Milvus and 20/1.8 Nikkor. I compared the 14-24 and 20/1.8 specifically for resistance for flare and ghosting and the prime was much better than the zoom in this respect. With the 14-24 this was sometimes an issue when doing landscape by the sea at sunrise/sunset; the image was riddled with ghosts. The 20/1.8 has also turned out to have excellent AF and I noticed that with the 14-24 there was greater uncertainty in focus in indoor shots with people in the foreground which I would focus on; the 20/1.8 just nails focus time and time again. However, despite excellent AF, the manual focus on the 20/1.8 is annoying and my lens has some slack when turning the MF ring and changing the direction of turn, making it slow to achieve perfect focus manually. Also at infinity I have noticed field curvature and some coma and gravity seems to affect the plane of focus a bit, making it difficult to get stars across the whole image sharp at the same time, or at least requiring great care in selecting the focus point. I got the Milvus because I wanted a nice manual focus ring for landscape and astro-landscape shots. It has turned out excellent for landscape. I have not compared the 21 and 20 side by side; I use each lens for different applications now. The 20/1.8 for events and interiors, the 21 for landscape. The 20/1.8 is easily what I would choose if pressed to own only one superwide angle lens. The 14-24 is excellent in its own right, particularly for interiors, but one problem was that I tended to slip the zoom too easily to 14mm end (I realize it was me doing the slipping, not the lens) and did not like the extreme angle of view, preferring the 17-24mm part of the range. I feel the 14-24 is at its best for interior and real estate images where shift can be simulated by cropping from a wider angle of view image. It has comparatively little vignetting and very even colour across the frame, making it particularly suitable for interiors with white walls. However, the zoom is a heavy lens for a wide angle and in practice I rarely took it with me to shoot because of this. The 20/1.8 is so lightweight that I don't have to think twice about including it in the bag, so it has become one of my most used lenses. Its only major flaws are the manual focus and slight tilt of the plane of focus depending on gravity and orientation of the lens at infinity focus. For general use I love it, and it contributes to my kit by being a light weight yet excellent fast wide angle. I pair it often with the 58/1.4 which is also light weight.
Landscape shots with the 21 Milvus
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