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

Observing and imaging a solar eclipse requires special filters to protect eyesight, lenses and cameras. The filters ready available are mounted in plastic or aluminum. These filters are attached like lens caps to the front of the gear used.
During a total solar eclipse, the filter may be removed for the short time of totality, when Baily's Beads, diamond ring effect or only the corona are visible. When shooting an eclipse it is always a bit of a hazzle to remove the filter when totality is finally visible and reattach the filter when the sun reappears.
To facilitate this, I created this filter holder, to mount Baader AstroSolar mylar filter to different lenses. This filter holder provides the flexibility to allways keep the filter at the front of the lens. Just flip away the filter when needed, or even cover the lens completely with the cover plate...

Filter fits 85mm lens barrels like Sigma 70-200mm 1:2,8

Parts required:
1x M4x50 screw
1x M4 nut
4x M4 washers (preferably teflon, polyamide, ...)
6x 2,9mmx6,5mm screws
optional 2x 8x1mm round neodymium magnets
1 round cut out of Baader AstroSolar filter foil

**** HINT ****
During tests on a hot day, when the filter was exposed to mid-day sun for a few hours, the cover piece printed in black material did warp. Therefore I recommend to coat primarily the cover plate with aluminium foil (use spray glue) or with chrome effect paint to reduce the heat build up during partial phase! Pay attention to paint the whole surface evenly and filling all gaps, ridges, ...

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