Solar eclipse photography filter holder for Baader AstroSolar filter, fits 85mm diameter lens

thingiverse

Observing and imaging a solar eclipse demands special filters to safeguard eyesight, lenses, and cameras. These filters come pre-mounted in plastic or aluminum, attached like lens caps to the front of the equipment used. During a total solar eclipse, the filter can be removed for the brief time of totality when Baily's Beads, diamond ring effect, or only the corona are visible. When capturing an eclipse, it is often challenging to remove the filter during totality and reattach it when the sun reappears. To simplify this process, I designed a filter holder to mount Baader AstroSolar mylar filters to various lenses. This holder allows for flexibility in keeping the filter at the front of the lens at all times. Simply flip away the filter as needed or cover the lens entirely with the cover plate. The filter is compatible with 85mm lens barrels, such as the Sigma 70-200mm f/2.8. Required parts include: 1x M4x50 screw 1x M4 nut 4x M4 washers (preferably teflon or polyamide) 6x 2.9mm x 6.5mm screws Optional: 2x 8x1mm round neodymium magnets 1 round cutout from Baader AstroSolar filter foil **Important Note** When testing the filter on a hot day, exposing it to mid-day sun for several hours caused the cover piece printed in black material to warp. To mitigate this issue, I recommend coating the cover plate with aluminum foil (using spray glue) or chrome effect paint to reduce heat buildup during partial phase. Ensure an even coat and fill all gaps and ridges.