Venus passage 2012

I decided that it would be a fun DIY thing to create a solar filter for the Venus passage. Using an old hard drive disk with a drilled and polished hole, and old unexposed but processed positive film, I made this filter for my Tamron 500mm f/8 mirror lens. I'd rather use metal than paper for the frame, because the smallish hole where the filter film goes has to be perfectly round.

A word of warning, though: Using dias film as a solar filter is dangerous. It blocks visible light, but not neccessarily IR and UV radiation. It may thus cause long term damage to eyes and equipment.

Between sunrise and end of transit, there were only two 5-min windows of relatively clear skies. The resulting images have a color tint because of the dia film.. I'm not very happy with the focus. So that something to work on until next time, in 2117 :)

For an upcoming eclipse, I'll use real sun filter foil for the filter (http://www.njopsahl.no/vis_varegruppe.php?varegruppenr=2&merkenr=17&varetypenr=32).

I'll also use a real telescope instead of a camera lens. The optics are better, compared to my tamron lens. And I can fit a focus motor. And a RA axis motor. And the tripod is much much more sturdy.