Øivind and Akira, Fun to see these transit of Venus photos from 2012. I'm very taken with the idea of using a CD as a solar filter! Another option is a granola bar wrapper, also made of aluminized mylar. In Antarctica, these are recommended as the remedy in case of lost sunglasses - to avoid snow-blindness!
In 2012 Seattle was cloudy for the transit of Venus, so I drove south to Oregon, where I watched and photographed it for several hours (first image). I drove home as it began to cloud over, but just south of Olympia I could see that the sun would re-appear below a cloud band before setting, so I stopped on a side road to watch the show. It was better than I could have hoped for (second image). As I watched I became aware of Mt Rainier glowing behind me, but I couldn't swing the camera away to take the third image until a moment after sunset. All taken with a D200 and rented 600 mm f/4. The third is stitched from two frames - I didn't have another suitable lens with me (nor would there have been time to change it).
Cheers, John