Originally posted by garywakeling Those are some stunning images. Now I want a FA 20 and FA 24. That is the closest I've seen to my beloved DA 15mm quality rendering.
Thank you everyone for their suggestions and sample images they are much appreciated.
My priorities for a landscape lens are:
Rendering - Color and Contrast are important to me, there is an almost 3d quality that great lenses exhibit (My FA 31mm comes to mind)
Flare Resistance - I shoot into the sun a lot due to shooting panoramas. My sigma has ruined a few panoramas or at least created post processing issues with its flare.
Vignetting - The Sigma has terrible vignetting this has ruined a few panoramas due to the lack of a good lens correction. Vignetting creates dark spots in skies if you are not very careful in overlapping with each shot. This has been partially solved by the reissue of the Tamron 17-35mm, I started using that new correction profile now, but even then that means that in wide or close to wide open aperture astrophotography im raising the exposure by 1 to 1 1/2 stops in the corners due to vignette correction.
Resolution - It is actually more important to me for consistency of resolution rather than trying to hit high numbers on tests. The Sigma sometimes is so blurry at the edges that it has to be cropped out.
I do not want a manual lens, because this will be my go to wide-angle lens.
Part of reason why the 15-30 is such a jump in price for me is that its not only the lens price itself, but as mentioned by biz-engineer, you need very expensive ND filter system that means another thing in the bag that now has be brought along. It is unlikely I would ever take this rig backpacking, I already hesitate carrying my K-1 on longer hikes.