Thank you Elsid, that was the first time I had seen them.
Thank you Akira, they are huge and framing is a challenge despite it being a large site, I have to admit I erased the power lines in the background because I find them so distracting. I think the 16mm fish could be one answer, esp. for a sunset. I try to arrange my visits to Scotland so I can detour that way, they are so different depending on the time of day, the light and the sky.
I visited again last year intending to make a combined star-trail and night time image of them but the ambient light was way too overpowering. As far as I know they are on all night, it would perhaps have worked if I had combined image of the Kelpies and then after they were turned off some darker sky images of the stars, but there is a lot of ambient light from more distant sources so I gave up.
Last year when we arrived there was a fashion photo shoot in progress, multiple photographers and models, soft boxes and lighting stands with a large crew. They eventually wandered off and left us to it.
As before, D3 but with Nikkor 24-120 f/4.0 at ISO 1250, 200 and 1600 respectively. They were exposed at 21:30, 21:33 and 23:35 hrs on 17 July 2017 I had planned to stay until 3am but the sky showed no sign of darkening by midnight, it was almost impossible to see any stars on a pretty clear night so we packed up and carried on to Lindisfarne which was another fiasco! But that's another story.