Building an Observatory – Part 5

The shed part is pretty much complete now. Last weekend I made the door, got the rest of the weathersheeting in place, finished the roof, and got the wood preservative on. I also added a 2×3 to strengthen the beam with the castors so that the ends no longer touch the track; I’ve to do the same to the other side sometime, but as it stands I can move the roof easily with one hand.  Read more

Hacking a webcam for long exposure astrophotography

I finally got around to hacking a Philips SPC 900 to enable it to take long exposure images suitable for astrophotography. The modifications are fairly well known. The approach I took is a mixture of the http://www.boltonastro.org.uk/Members%5FArea/Projects/spc880conversion.pdf from Bolton Astronomical Society and http://www.yesyes.info/index.php/diy/philips-spc900-webcam-lx-and-ampoff-mod/ .

The circuit between both approaches is roughly the same, I followed the circuit in the former. The modification allows the camera to be switched to a long exposure mode via a switch. The switch can be triggered over a serial port, so I added a USB to serial adaptor and a USB hub (both from ebay) to the unit to allow control from a computer and have just one cable coming from the unit. Read more