Extinction Scale Factors

This includes a printout of part of an Excel spreadsheet. As best I can tell, my images have not been blue enough. (!?)

http://www.fortlewis.edu/observatory/image_detail.asp?ID=210

Would a Java applet be useful? Comments?

In the mean time, I was planning on observing tonight, but the sky full of smoke does not show up on the Clear Sky Chart!

Charlie

Very interesting Charles, an app might be nice.

Charles,
Interesting, I have been using Extinction Scale factors for some time now. the table I use I developed from some other data and they are not as strong as yours.

http://www.jthommes.com/Astro/ExtinctionRates.xls
Also some examples here:
http://www.jthommes.com/Astro/NGC5128_ColorCor.htm

I have also taken into account various altitudes - Sealevel, 1, 2, and 3 KM in altitude.

I have had good luck with the coefficients generated by the eXcalibrator program, which uses the extensive star color databases available through the Aladin Sky Atlas Program in an approach more sophisticated than simple G2V matching. Nice feature is you just create your composite RGB images, w/o having to pay attention to the elevation or conditions under which the individual images were generated. Then you feed them to eXcalibrator, and get back the coefficients.

Anyone else have experience with eXcalibrator?

- Barry

Charles Hakes said:

This includes a printout of part of an Excel spreadsheet. As best I can tell, my images have not been blue enough. (!?)

http://www.fortlewis.edu/observatory/image_detail.asp?ID=210

Would a Java applet be useful? Comments?

In the mean time, I was planning on observing tonight, but the sky full of smoke does not show up on the Clear Sky Chart!

Charlie