Light as a ....

The 2 feathers shown are quite different. The larger one is a structure feather, and the smaller is more similar to a down feather and is from the breast of the bird. The whole feather is called a shaft.

The Calamus is the short, hollow, tubular, unpigmented end of the mature feather which is below the skin. This is the part of the feather that can be used as a quill for writing.

The Rachis is the long solid, tubular extension of the calamus above the skin.

The Vane is the portion of the feather that extends to either side of the rachis.

In both feathers it's possible to see the after-feathers which are soft and downy.