This effect template creates a magnifying glass effect that is animatable via keyframes. You need the same clip in two adjacent tracks. The effect goes on the clip on top. Use the first Transform effect to move the magnifier to the point you want magnified; the second Transform effect is needed to move the magnified clip to the right spot. You can change the magnification level by adjusting the Amount and Manual Scale parameters as needed. The Alpha Shape Mask effect is used to smooth the edges (no Mask Apply effect needed).

When installing just install the XML file. The magnifying glass is available for your convenience courtesy of Pixabay (https://pixabay.com/vectors/glass-icon-magnifying-magnifying-2025715/) and needs to be downloaded separately. Of course, you can use any other image file or none at all.

Thanks to /reddit user Koallitu for the inspiration (https://www.reddit.com/r/kdenlive/comments/1c97nt2/is_there_a_way_to_recreate_the_spheric_effect/)