Filter adapter for smartphone telephoto lens

thingiverse

A simple adapter to fit a 49mm neutral density filter to a smartphone telephoto lens I purchased online. The filter is variable, it has a 2ND to 400ND range. The fit was a little loose on the filter so I placed a small rubber band on the threads. The result is a nice, tight fit but I can still remove the filter if necessary. The adapter fits snugly on the telephoto lens, it was designed to fit the 36mm barrel of the lens, the socket is tapered from 37mm to 36mm. The whole purpose of this is to photograph the August 21st, 2017 eclipse. If things work well I'll post some follow up photos. UPDATE: While the filter adapter was close the sun was still significantly brighter then what I felt was safe for the lens of the camera. What I ended up using was a combination of filter and eclipse viewing glasses. The filter did make it easy to adjust the exposure level once I had the eclipse glasses aligned, Unfortunately it was difficult to get both in perfect alignment, I've uploaded the best picture I was able to capture. it was still far better watching it with a second pair.