Oh, thanks! Well this image was shot with Nikon Nikkor 14-24mm wide angle-zoom. It doesn't accept any filters so no such things used here. Instead, 9 exposure HDR is used to mimic the effect of graduated neutral density filter. The other shots have been taken with Sigma 10-20mm zoom (old version) + CL polarizer if Pentax body was used (can be seen in the EXIF) or with this Nikkor lens if Nikon D700 was used.
Doesn't really matter whether it's the Sigma or the Nikkor or just about anything. Both will provide equally good results. Just make sure your lens is as distortion free as possible so you don't have to do much correction in PP (some loss of detail). Sigma 10-20mm accepts GND / CL-polarizer filters AND is distortion free so I can fully recommend it if you want such wide lens for Pentax.
Filmstrip
Maffer's Photos - Landscape - "Night Watch"
