Say you have a virtual map and its at 1x zoom (normal). The map is going to zoom to a scale of 10 in 7 seconds.

The time for transitions between zoom levels is not evenly distributed, since zooming from level 1 to 2 is a scale of 2, and zooming from 5 to 6 is a scale of 1.2.

I have control of the zoom of the map, but i can only zoom from level 1 to 3, 3 to 5, 5 to 8 then 8 to 10 in those increments. How do i calculate the time for each of these increments so the zoom appears completely smooth over the total time?

Just used example figures so if you can help please dont just give answer. Must be very simple for u mathematicians but cant get my head around combining scales distance and time. Many thanks for any help.