New Baader Herschel Wedge Solar Prism
Posted 27 December 2010 - 06:13 PM
Could you help me understand what combination of filters works best if I decide not to use the Solar Continuum filter but do go for a polarizer - in other words, which ND filter would I need to use together with the polarizer?
Alternatively, have you explored the use of the solar continuum filter together with a coloured filter to result in a more 'natural' colour of the Sun's disk?
Posted 28 December 2010 - 08:44 AM
Posted 28 December 2010 - 11:30 AM
Getting the itch, once again, to purchase a solar wedge.
Posted 28 December 2010 - 04:13 PM
Posted 28 December 2010 - 08:53 PM
Posted 31 December 2010 - 11:58 AM
From Alpine Astro:
“This development takes the Herschel Wedge into the 21st Century, by rendering the output energy cool and diffused, while completely sealing the prism body! In all other herschel designs, the waste energy is simply deflected out of the rear face of the prism by an angled mirror, also leaving openings for accidental or prying fingers to discover... Thanks to Baader Planetarium, this concern has now been completely removed.”
This is then referred to in the recent CN review by Ted Wolfe:
“In the fall of 2009 I began to see descriptions of a new solar wedge from Baader Planetarium, which promised excellent visual and photographic detail of this intriguing region of the sun – along with greatly increased safety. White light observing with a typical Herschel wedge focuses an enormous amount of solar energy which exits the prism. This forms a diffused, but still potentially harmful beam behind the housing, especially after prolonged usage.
Baader had been studying this problem for 15 years. Their new approach involved the use of a “heat cage” (multi-layered perforated steel screen) with a heat absorbing ceramic tile in the back of the housing. Baader believes this combination results in the safest white light wedge on the market."
The invention, and proof of concept, of the enclosed and ventilated Herschel wedge – and the reasoning behind it -- was discussed right here on Cloudy Nights in June of 2005, long before the introduction of enclosed wedges by APM/Lunt and Baader:
Full thread CN Archive web page
The primary purpose of the "wedge absorber" is to block the intense beam of reflected sunlight coming out of the bottom of the wedge -- See the thread's first image. Secondarily, it will keep curious fingers from getting too near the exit beam or touching the rear of the prism (an advantage over the Baader wedge's diffuser design).
As can be seen in the above Cloudy Nights posting, I actually measured the heat that was contained inside the enclosed/ventilated wedge to show that it was completely safe, as well as practical to implement. While I chose not to patent this invention so that it would remain available to the amateur community, and have no trouble with Baader and APM/Lunt adapting this for their commercial use to allow for the absolutely safest wedges to be manufactured, I had hoped none would claim credit for the invention or the principle.
While to my knowledge APM/Lunt has not done this, it is disappointing to see that Baader has.
The original enclosed/ventilated Herschel wedge with temperature sensor, June 2005. It uses a vent opening with a CPU cooler, with holes which were later drilled in it to pull air through the wedge. The fan has proven to be unnecessary (though helpful), as convection results in more than adequate ventilation:
Posted 02 January 2011 - 06:11 PM
I would love to see how the Baader compares to the Lunt wedge. I'm still partial to Baader.
I own neither, but I’ve used both. The view is the same, but I like the Baader’s physical structure better. That’s the one I’m going to get.
Posted 03 January 2011 - 04:46 PM
Posted 17 January 2011 - 01:50 PM
Posted 21 January 2011 - 04:10 PM
Posted 08 January 2012 - 03:29 PM