Siegfried is having trouble posting to the list. I'm working on that but in the mean time here is a message he tried to post earlier today. patrick The Energy Rejection Filter (ERF) was lent by John Pons because there was concern about the quality of repair done by DayStar. After viewing through the filter with the 8” Bogdan stopped down to 4.5” I would say the filter is working great. What we were looking for was detail in the Chromoshpere and we had it in spades. It sat above the Photosphere thin and jagged. We could also see the slight separation between the Chromosphere and the Photosphere. Due to the lack of detail on the surface during a quiet Sun it is often difficult to assess the quality of the filter or total setup. The test then is the Chromosphere. The Chromosphere is not dependent on solar activity. It’s always there. This was as good as I have seen the Sun in years. The filter has a retail value around $1,000 - $1,200. It is being offered to us by John at $400. I recommend buying it and having it available to SLAS members. Perhaps a dedicated solar eyepiece should also be purchased, something like a 40mm Pentax with lots of eye- relief and a 70 deg wide AFOV. That combination would give about 85x and a .82 deg FOV. The entire disk of the Sun would easily fit into the FOV. I think it would be great to have this in place by Stansbury Days. Siegfried On 27 Jul 2008, at 22:22, Patrick Wiggins wrote:
Those who arrived a SPOC early yesterday got a real treat.
Siegfried Jachmann brought a large rejection filter with him which Bruce Grim was able to kluge to the front of the Bogdan refractor. Roger Butz then attached SLAS's newly refurbished .5 Å research grade H-Alpha filter in front of the eyepiece.
The results were spectacular!
Grandularity in the photosphere practically jumped out of the eyepiece at the viewer and while there weren't many prominences those that were there were contrasty and a delight to the eye.
I can't wait until there's a chance to use the set up when the Sun's high in the sky (like at next month's Stansbury Day and at the Star-B- Q).
Better still will be when there's more solar activity (yesterday's prominences were not very big and there were no sunspots).
'Course in order to do that SLAS is going to need to buy the rejection filter since the one Siegfried brought was only on loan from someone out of state. I think Sieg said the owner wants $400 for it.
patrick