23 January 2006

Sunspot group 848 has continued to grow in size and complexity, but it rained all day here so I haven't been able to observe it.

A while back I made my first attempt at moding my RadioShack ear LED flashlight. I saw a plastic bag that had red printing on it and decided to see how it would do as a filter. I cut out a section of the red portion of the bag and taped it over the lamp portion of my light. Unfortunately it was too dense and attenuated the light too much. To be able to see with it I had to hold it by hand right against my PDA thumbboard, which negates the advantage of having an ear-mounted light. The bag I used was a DuaneReade bag which is white plastic that was overpainted with red and blue paint. It was clear that I needed a clear bag printed with red ink, or better yet, a red bag with no ink.

I found an Office Depot bag that is a much less dense white plastic with a lighter shade of red ink over it that I am trying now. Tests here in the apartment indicate that I will be able to read with this filter but when shined on white paper the light is only faintly pink and may not produce enough of a frequency shift in the light to preserve night vision. That isn't a big concern at TotL where there is plenty of light from street lights and surrounding buildings, even the NYPD helicopters lighting us up with the Midnight Sun, but at a dark sky sight where it is possible to dark adapt it night be a problem.

I am remembering that the Oriental supermarket near me uses bags made of red plastic and there is probably one here somewhere, if not there will be soon, so that will be my next test.