Mat, I read Jay's blog about the mud adventure. What was old, is new again, lol. One day I'll tell my decades-old tales of driving through foot-deep snow to dark-sky sites, in my '74 Toyota Landcruiser with 34" tires and 10" lift kit. LOL! (I miss than money-pit of a vehicle, sob!) As far as the horsehead incident goes, a couple of things could be taking place. Were the views with the different filters in the same telescope? Think about the way narrowband filters work. It's the interference principle. They are very sensitive to f-ratio. Think angle of incidence and the tiny distance between reflective layers of the coating. Interference filters can have a very different effect between telescopes of differring f-ratios. One reason H-a solar filters work best with long f-ratio objectives. If it was the same telescope, then I suspect one filter was more effective at reducing the ambient LP at your observing site. They both probably passed the same wavelengths, within a few percent, but one might have blocked the predominant LP wavelengths better than the other. On Tue, Feb 21, 2012 at 4:08 PM, Hutchings, Mat (H USA) < mat.hutchings@siemens.com> wrote:
As far as the horsehead goes, I did hit it with an O3 filter (Orion brand) and this was verified by Jorge. A very curious thing happened though, that I cannot explain. Jay has an H-Beta filter (Orion brand) that he let me use on the same eyepiece (my T.V. 22mm Panoptic) that Jorge and I observed the horsehead with and it actually looked much more apparent with the O3. This is not supposed to be how it works. The H-Beta is supposed to make the horsehead more visible. Anybody have any thoughts on this?