Nikon 50mm f1.8D AF Nikkor  type_Adapters and while it's not exactly

and while it's not exactly featherweight- it's about 400g with film- it's compact enough to tag along almost anywhere

Olympus 9mm f8 Fisheye lens for Micro Four Thirds

it's definitely smaller than many other options

Fujinon Aspherical Super EBC 60mm f2

4k60 video

Nikon 50mm f1.8D AF Nikkor &nbsptype_Adapters and while it's not exactlyThe Nikon 50mm f1. 8D AF Nikkor is a nice, compact standard lens for film and digital Nikon F mount SLRs. The autofocusing system in this lens requires an in camera focusing motor: it will mount to non motor SLRs like the 3000 and 5000 series, but it won't autofocus. In excellent condition, with clean glass and minor cosmetic wear.