Filter adapter for smartphone telephoto lens

thingiverse

A simple adapter enables attachment of a 49mm neutral density filter to a smartphone telephoto lens purchased online. The variable filter features a range of 2ND to 400ND, providing flexibility in adjusting exposure levels. Initially, the fit on the filter was loose, requiring placement of a small rubber band on the threads for a secure hold. This modification ensures a tight connection without compromising the ability to remove the filter if needed. The adapter fits snugly onto the telephoto lens, specifically designed for 36mm barrel compatibility, with a tapered socket that gradually narrows from 37mm to 36mm. The primary objective of this setup is capturing high-quality images during the August 21st, 2017 eclipse. Future updates will include follow-up photos if the system proves effective. UPDATE: Although the filter adapter provided an acceptable fit, direct sunlight exceeded safe exposure levels for the camera lens. A combination of the variable filter and eclipse viewing glasses was employed to achieve optimal results. The filter facilitated precise adjustment of exposure, yet achieving perfect alignment between both components proved challenging. The uploaded photo represents the best possible capture under these circumstances, demonstrating significant improvement over naked-eye observation with a second pair of eclipse glasses.