Hi Andy.
Thanks for the comments.
(BTW, the foliage technique in the foreground was plagiarised from the guy that runs that bridesnightie.com site!)
I hadn’t noticed the backdrop problem. I’ve had another look and tweaked. It’s not one whole backdrop, it’s five curved ones, overlapped and laid across the top of the far hill ridge.
I’ve made them rollable in their config.txt files so that I can adjust the angle and appropriately slope them into the hillsides. I’ve now rolled just the two end ones so they taper into the baseboard, avoiding an abrupt straight edged end.
I’ve added a few bits of foliage at the foot of the backdrops to break up the join line.
The dark green thin hedge spline also looked too straight, so I’ve twisted that a bit. I’ve also changed some of the texturing. Some of the background greens were a bit too straight and regular, so breaking them up a bit might improve the overall impression.
Here’s the long shot again, (with different loco). Any better?
Added observations following preview prior to posting.
The dark green hedge spline looks too dark and might be better re-laid in a lighter colour or fence.
The distortion illusion remains. It could be due to the bridge, which is not straight. It has been perfectly made by samplaire with the arch angled at 45deg, but the camera angle I've taken the image from makes it look 90deg. I'm wondering if that might just be the problem. The angles of the retaining walls could be fooling the eye. I've been covering up various bits of the screen to try to isolate the problem and that looks a possible cause. A fresh look at it later is probably a good idea.