Here's another of Iceland's most photographed waterfalls, this taken looking downstream instead of the more usual upstream shot. Thanks to Don's sharp-eyed observation on my previous post, I looked for evidence of barrel distortion in this one. It's hard to tell, at least for my untrained eye, but when I applied a moderate amount of distortion correction using the PS distortion filter, the result seemed to improve it. I tried several different shutter speeds and liked this the best of what I took, but I think one just slightly faster might have made the water a bit less foamy. I guess it's a matter of personal preference.
D7200, Nikon 18-70 @ 18mm, ISO 100, 1/2s @ f/16 manual, ND filter, Gitzo and Mongoose. Full-frame except for the crop due to distortion correction.