I am resizing the big .jpg files of all subdirectories to a maximum height of 520 pixels. Why? Because a photograph 520 pixels high fits snugly on a laptop screen of 15" (diagonal) when employing a zoom value of 125% (which is recommended for comfortable reading).
I have resized forty-seven photographs from "WhenIWasAChildInFerrol" to ensure they fit without scrolling on my laptop screen and probably yours too; these forty-seven photographs now have an uniform height of 520 pixels
sounds like it was some undertaking.
made easier with free online resize app :)