When you set layout scale to 2, layout will be zoomed in x2.
When scale = 3, zoom in x3.
But when you zoom out you must use values between 0-1
By try and error i find out:
scale 0.5 = zoom out x2
scale 0.333... = zoom out x3
scale 0.25 = zoom out x4
What function do I need to use to find right scale when I know target zoom out rate.
zoom out x5 = scale ???