My ND3 has gone! Correct way to used Herschel Wedge

My ND3 has gone! Today I found out the reason that why there are unknown marks on my Herschel Wedge images since last solar observation in 25/5/2010. The marks on the image would not rotate with the camera. And I found there was no dust on the CCD, the filters and the Herschel Wedge. There were no visible damages in any optical parts. However, the problem was more pronounce in high magnification. Today I detach the ND3 and inspected it under the sun. Gosh! There were cracks on the ND3. I remembered that last time I reversed the order of assembling the Herschel Wedge. The ordering was:

Objective side, ND3, Herschel Wedge, Polarizer or Green continuum, Eyepiece side (WONG!!!)

This ordering terms out to be wrong. My ND3 cannot stand for the heat energy and micro cracks formed! I need to buy a new one now! Dear Herschel Wedge users, don’t repeat my silly fault. The correct ordering should be:

Objective side, Herschel Wedge, ND3, Polarizer or Green continuum, Eyepiece side (RIGHT!!!)

Cracks under strong light

No visible damage under normal light

Unknown marks on the image

24-5-2010 Sun (Active region 1072)

A long waited blue sky! But the weather forecast in the coming week is bad! Just one day!!!

LS 35T, TV 5X, DMK41, Best 95% of 150 frames

LS 35T, TV 2.5X, DMK41, Best 95% of 150 frames




LS 35T, DMK41, Best 95% of 150 frames

The treasure solar image in 24-4-2010

The sky in HK is really disappointing! It has been cloudy, foggy and misty for more than 3 months! Even the sun is hardly found during daytime! This is a treasure shot recently!

LS35T, stack of best 95% of 450 frames

2010 Easter Taiwan Trip

This Easter I went to southern Taiwan for a vacation. I visited Kaohsiung(高雄), Hengchun Peninsula(恆春半島), Szchung River Hot Springs(四重溪溫泉), Kenting(懇丁) etc. This was the first time I did stargazing overseas. However, starting from 1/4/2010 to 7/4/2010, the sky was not cooperating. I took only one photo of the big dipper. During the last night in Taiwan, I drove about 20km from the hotel, Maya House (瑪雅之家), to Lungpan Park (龍盤公園) and Fengchueisha (風吹沙) alone and try my final effort to see if any chance for me. Well the sky was very dark. Nothing can be seen in the rear mirror of my car. The road was dead silent! It is quite scary to do stargazing alone in this situation. Anyway, the sky was covered by clouds! I finally quit!

26-3-2010 Sun (1057 Active Region)

I just find this organization provides the solar information, including the nomenclature of action regions.
http://www.solarmonitor.org/
http://hesperia.gsfc.nasa.gov/sftheory/questions.htm#AR_numbers
http://www.swpc.noaa.gov/ftpmenu/index.html
Seeing: 3/10
Transparency: 4/10

LS35T, DMK 41
LS35T, DMK 41

LS35T, TV 5X, DMK 41

Equinox 120ED, Herschel Wedge, TV 5X, DMK41

Small scope & big prominence

The big prominence diminished a bit today.

LS35T

LS35T

LS35T + TV 5X

The First Light of Herschel Wedge

Due to the recent poor weather in Hong Kong, my new APM 1.25” Herschel Wedge has been waited in the storeroom for a few days. Although both transparency and seeing were bad today, the sun was awaken! After I used my LS35T to shot the big prominence, I compared the Thousand Oaks Optical Solar Filter Type 2+ & Herschel Wedge. Luckily, the sun has a very small sunspot. It is not obviously showed in my little LS35T. The resolution of LS35T is not high enough to see the detail of the small sunspot. I deliberately used the Oaks Optical Solar Filter Type 2+ & Herschel Wedge on Equinox 120ED respectively. The sun surface showed by Thousand Oaks was quite flat. However, the sun surface showed by Herschel Wedge has details! The color of Herschel wedge is natural and the image is of high contrast compared with Thousand Oaks filter. In terms of safety, I like the Herschel Wedge because if it is taken away, basically one cannot do observation. On the other hands, if a front solar filter is accidentally dropped off, one can still place his or her eyes behind the eyepiece. This is disastrous! In terms of flexibility, the Herschel wedge wins. It just virtually turns any refractors into a solar scope! Well nothing to say & let the photos speak for them.

Equinox 120ED, TV 5X & Herschel Wedge

Equinox 120ED & Herschel Wedge