The Alum Anamorphic is a 1.33 focus-through anamorphic adapter. The adapter was my first foray into lens design and is a very simple two element formula. The adapter is designed primarily for use on small (rangefinder style) 35mm lens. It works quite well on smaller formats with an equivalent focal length as well. The adapter is optimised for shooting around f/4 and is focused at 3m.

Anamorphic adapters change the focal length of your lens in one direction, and not the other, therefore the two focal lengths (horizontal and vertical) now focus at different rates. The adapter is therefore focused to give the sharpest results at 3m, at any other focus distance, the two focal lengths will be focused differently and you will get increased astigmatism in your image (blur). It is possible to shim the adapter, moving the front lens forward to achieve a different optimal focus point, mainly longer focus distances. The shims can be 3d printed with some template files found below.

The first edition of the adapter was released for in March 2024 and sold out almost immediately, the second edition was available for pre-order in June of 2024 and started shipping in early 2025 due to production issues

A third edition is currently in the works, with a revised optical design.