I've posted a similar question before. So far, it's had 57 views but no replies. I really would be grateful if someone could check this out on their computer screen and let me know.
The error is quite simple: the horizontal scale is 96% of the vertical scale. For example, if I use the ruler tool to draw a 5 km straight line, vertically it is 23.3cm while horizontally it is 21.1cm. Looking at the screen, the kilometre squares of the Ordnance Survey are obviously not square. The vertical scale is “correct” because it matches the scale at the bottom of a map printout. The error is there whether an .img map is showing, or whether a UK Ordnance Survey overlay is showing.
I’d be most grateful for any light anyone can throw on this, if only just to measure a line on your screen. It is BaseCamp 4.8.11. I have tried this on an iMac (OS Mojave) and a MacBookAir (OS Big Sur): it is the same on both machines. Is there some simple setting that I have overlooked?
