Set a maximum height and a minimum height, both in VH, on desired elements. (and no height). The min height value will be set for shorter viewports, the max one for taller viewports.
Works for the elements, thank you and had actually tried this concept on a slideshow.
Trying this for font sizing as well but proving difficult as want a larger font for higher resolution screens (desktop) and then a smaller font for lower resolution screens such as my laptop. Designing on the desktop I can get it looking right but then going onto the laptop the fonts are huge! (Tried, EM and VH for sizing and stuck with EM for now).