Archive for November 1st, 2013

The Great Pumped Pumpkin

Halloween has come and gone and I did promise you pictures of a pumpkin being lit by a 100W LED. Not a hundred watt equivalent, but one that draws 100W.

Here it is in normal daylight. The intent was to make the Milky Way. I did that because I cannot carve for shite.

As it got darker the darned thing got harder to photograph, requiring stopping the camera down to F/22 if I was going to catch the pattern.

The other trick is to back way the hell up and reduce the amount of light that way. This is with the power supply cranked down as far as it would go.

This is full-on and with the top cracked a bit to let more photons out. It hurts to look at and you don’t dare look inside the pumpkin.

Note the water cooling hose. That is a garden hose turned on to “trickle” but it was necessary and worked very well.

Next I will collimate (as much as you can collimate a huge extended source without an asphere and lots of distance) the LED output and send it through a spare prism I have laying around… Dark Side of the Moon. Gonna be a hell of a demagnification. Might have to search the net for some lenses to do it. They are cheap on eBay.

I am sure there are worse things, but I cannot think of them.

Maybe more later. Maybe.

Read Full Post »