Saturday, January 31, 2009

20090130 Moon and Venus

Taken in Tai Mo Shan when I went camping with friends, Canon 200 f2.8 with Canon 450D.

20090131 Sun

Very silent again, seeing 3/10, transparency 7/10.

1313 (GMT+8):-

1315 (GMT+8), note the long but very dim prominence:-

Friday, January 30, 2009

Equipment Check List

I'm going camping tonight with friends, and so I'm writing these check lists to make sure that I've sufficient and working setups.

TG-SP II based imaging setup:-

1. TG-SP II main body
2. V shape bracket (wedge)
3. Gitzo G106
4. Hand controller
5. Power supply (SLA or AA battery pack) + power cable
6. Counter weight plus shaft
7. Compass for rough idea about north
8. Munting plate

1. Camera body
2. One more battery
3. Timer release with two AAA batteries
4. Various lenses

1. Borg 45ED II
2. JMI focusing controller
3. Diagonal
4. Meade reticle

LXD55 based visual setup:-

1. LXD55 mount
2. Gitzo G1415
3. Counter weight plus shaft
4. Power supply (SLA) + power cable
5. Autostar

1. C5 with diagonal
2. Various eyepieces
3. Rigel Quick Finder

But where are my camping stuff?

1. Sleeping bag
2. Mattress
3. Bowl + Cup + Fork
4. Food.... and I'm sure I will miss something out...


Added at 15:15, the above setup is proven to be too bulky, now the G106/TG-SP II will be left at home, the LXD55 will also serve as the imaging platform after visual observations.

My camping stuff is "enriched" with:

5. Water bottle
6. Clothing
7. Towel!
8. Sugar free chewing gum
9. Toothpick

And I found that I missed the counter weight shaft of the LXD55!

Friday, January 23, 2009

Solar Image Processing: Registax

Actually, there's nothing special about solar imaging if we talk about using Registax. The usual practice for planet works perfectly for solar images.

First of all, you input your AVI. Your AVI should better be in RGB24 or Y800. Y800 is the better choice since it works with less hard disk space. It loads with less memory space too, and with the reduced data size, it works faster too.

Choosing the alignment point is important. Narrow band solar imaging is usually lack of contrast, unless you have a very good sky and a very narrow bandwidth filter. You will want to find a good alignment point where the contrast is maximum. A small and contrasty feature is the perfect candidate. A thin but long feature is bad usually except the both ends.

Automatic processing usually works, but in case where the seeing is very bad, or the final result is blurred due to poor image registration, you will want to disabled automatic processing.

If you have disabled automatic processing, you can choose how to select frames to be stacked. Discarding the poor quality ones are usually good, and you can also discard those frames which a big difference than the reference. Those frames with a big difference are usually a result of poor alignment (registration).

Next you have the stacked raw. Check if it's blur, if so, re-do the alignment or exclude some poor frames with the techniques I mentioned above.

Finally, adjust the wavelet. A good image will usually allow simple sliding the first level all the way to a point before noise become too ugly. If the raws are no good, choose level two or even lower levels.I usually save as BMP and then I will further adjust it with Photoshop/GIMP or whatever software that you love.

On stacking, you can choose the stretch the history in registax, but I didn't recommend it for solar imaging due to uneven illumination and non-uniform bandwidth across the whole field. Stretching the histogram could expose all those issues. We can do this with other softwares for better results.

Next time I shall talk about how to make your b/w image into false color image, and also how to do the final processing like to bring out the prominence in a surface detail exposure, etc. Comment and questions are welcome.

Thursday, January 22, 2009

20090122 Sun

Seeing 5/10, transparency 1/10, very foggy sky, it's white basically but there's no cloud if you look at the sun. The sun is very silent without any activity virtually. I pulled out my Borg 45ED II, removed its extension tube to use a reducer in front of the BF10, so that the whole solar disc can be captured with my DMK 21AU04.AS in one shot.

1210 (GMT+8):-

1212 (GMT+8):-

The Sun by Steele Hill and Michae Carlowicz

I have more time to observe and to write these days, and therefore, other than all the previous topics, I will also start writing about some books that I have on my book shelf. This is the first one of this series.

Being an active solar observer, I really wanted to buy some related books from the first day. However, this kind of books is very limited and some really good and informative books were no longer available. Without too much choices, this is the first one which I bought. I got it from Amazon.

This is not exactly a technical book. You know what, I believe most more technical but still "amateur" books are out of print. This book is not really for active amateur solar observer, but it's more for general public who has interest on the sun.

The content is more like a coffee table book with many excellent photographs. The text is simple and nicely written.

Chapter one is called the Sun King. It talks about how important the sun is to the Earth, along with many excellent photographs related to this topic. Chapter two is called the tricks of light. It's about the atmospheric effect on sun light. Expect beautiful photographs of rainbows, solar halo, sun piller, green flash and their descriptions. Chapter three is called "I'll follow the sun", it's about how people from ancient time to modern days response to the sun. Chapter four is about auroras, to make it short. Chapter five is to look at the sun from the point of view that it is our star. I believe amateur solar observer will interest in this chapter the most. The next chapter is about space weather, i.e. how the sun could affect our life. The final chapter is called "beyond the sun" and you can guess what it's going to discuss about.

After all, it's a very good book to introduce the sun to your friends, or to get you interested about the sun.

Wednesday, January 21, 2009

20090121 Sun

Sunny again! Transparency is 7/10, seeing 4/10.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40 with BF10
Camera: DMK 31AF03
Mount: Meade LXD55

No big active region except a small and subtle one, prominence activity low except a slightly longer one.

1322 (GMT+8):-

1323 (GMT+8):-

Aeroplane passed by to generate some fake prominence:-

Close up with 3x barlows:-

1329 (GMT+8):-

1331 (GMT+8):-

1334-1343 (GMT+8):-

Tuesday, January 20, 2009

Partial Solar Eclipse during Sunset

We will have partial solar eclipse during sunset in the first day of the Chinese (Lunar) New Year! Tradition thinking is that it's not a good sign, but for amateur astronomers, it's a great event indeed.

During sunset, you can see the sun without any instrument, that means you will see the eclipsed solar disc together with the scenery! That should be a great chance for photography as well.

Another exercise could be a partially eclipse solar disc in H-alpha. That should be interesting. If there is a large prominence which is first eclipsed by the moon, it will be captured in H-alpha as well! At least I never saw a similar picture or video clip myself.

For that regard, I have just tried to use a 0.5x binoviewer corrector in front of the BF10 which should reduce the size of the solar disc, and it could indeed reach focus. That setup would allow me to capture the whole solar disc with my DMK 21AU04.AS which has a smaller chip than my DMK31AF03, but it's easier to setup in the field than the 1394 model. My Borg 45ED II setup is just flexible in terms of focuser travel.

The weather forcast is not very favorable so far, but let's hope.

20090120 Sun (Cloudy)

White light first, and then H-alpha with reducer to test the image scale. Cloudy, featureless essentially. Seeing 2/10, transparency 1/10.

1357 (GMT+8), taken with my Borg 45ED II, APM Herschel wedge and BW ND3, cloud was moving but was averaged out by stacking:-

Next is a video clip which shows the sky condition, notice that the first part of the video is in white light, i.e. the same setup as above, and the second part is in H-alpha. As you can see, white light is much more affected by seeing than H-alpha. Prominences can be seen from the H-alpha despite it's cloudy by overexposure.

Finally is another video clip which is taken in H-alpha, a 0.5x binoviewer corrector is attached to the BF10 and it makes the solar disc small enough for my DMK 21AU04.AS. As you can see, surface detail can be seen when cloud is of "suitable" thickness and exposure.

This setup should be easier for out-door imaging due to the USB interface is simpler to use and setup in the field.

Monday, January 19, 2009

20090119 Sun

We have two big prominences today, and they're very close to each others, a very good view indeed! Seeing is very bad at 2/10, transparency 5/10. There is a small active region near the center of the solar disc.

Telescope: Borg 45ED II
Filter: Solarmax 40 with BF10
Camera: DMK 31AF03
Mount: Meade LXD55

1331 (GMT+8):-

1333 (GMT+8):-

Next couple of shots are taken with a C5 with Cheapy-ERF, PST etalon with BF10:-

1342 (GMT+8):-

1344 (GMT+8):-

1346 (GMT+8):-

Saturday, January 17, 2009

20090117 Sun

Seeing 4/10, transparency 7/10. We have a very nice prominence today!

1341 (GMT+8):-

1342 (GMT+8):-

1343 (GMT+8) with 2x barlows, the active region is about to disappear:-

1344 (GMT+8) with 2x barlows, this one has shorter exposure:-

1346 (GMT+8) with 2x barlows, this one has longer exposure so that the base is overexposed, but the dimmer detail turns out better:-

Friday, January 16, 2009

20090116 Sun

Seeing 3/10, transparency 7/10. My Borg 45ED II based setup. AR1010 is about to disappear, nothing special on the solar disc. A small but feature rich prominence is there.

1221 (GMT+8):-

1222 (GMT+8):-

1224 (GMT+8), with 2x barlows:-

1226 (GMT+8), with 2x barlows:-

Visual observation rendered a nearly featureless disk, but binoviewer brings out the detail, the area around AR1010 is very nice and nearly 3 dimensional, that small prominence is very great in the eyepiece, very fine detail can be seen.

Thursday, January 15, 2009

20090115 Sun

AR1010 is here, and a new active region is forming in the middle of the disc. Seeing 3/10, transparency 6/10. All images taken with my SM40/Borg/BF10 setup.

1313 (GMT+8), we can see the new forming active region near the middle of the disc:-

1314 (GMT+8), prominence activities remained low:-

1316 (GMT+8), close up of the two active regions with a 2x barlows:-

Wednesday, January 14, 2009

20090114 Sun

AR1010 is still here, seeing 6/10, transparency 4/10.

Telescope: Borg 45ED II
Camera: DMK31AF03
Filter: Coronado Solarmax 40 with BF10

1603 (GMT+8):-

1604 (GMT+8):-

1607 (GMT+8) with 2x barlows:-

Tuesday, January 13, 2009

20090113 Sun (AR1010)

AR1010 is still here, but it seems like that it's "dissolving", seeing 5/10, transparency like 6/10.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40 with BF10, also PST etalon module
Camera: DMK 31AF03
Mount: Meade LXD55

The first two are taken without the PST etalon, 1409 (GMT+8):-

1410 (GMT+8):-

PST etalon added, 1412 (GMT+8):-

2x barlows also added, 1416 (GMT+8):-

Monday, January 12, 2009

20090112 Sun

AR1010 is developing, seeing is 4/10, trasparency 7/10.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40 with BF10
Camera: DMK 31F03
Mount: Meade LXD55

1353 (GMT+8), full disc:-

1354 (GMT+8), full disc prominences:-

1357 (GMT+8), AR1010 with 2x barlows:-

1357 (GMT+8), this one is the raw video of the above image, and this one has an aeroplane passing through!

1402 (GMT+8), a nice prominences:-

1403 (GMT+8), AR1010, but with different T-max tuning:-

Sunday, January 11, 2009

20091011 Sun

AR1010 is still fine, but that smaller active region is nearly totally disappeared. Seeing 3/10, transparency 7/10.

Borg 45ED II, Solarmax 40 with BF10, DMK 31AF03 for the first two shots, Tele Vue 2x barlows added for the close up.

1515 (GMT+8), full disc:-

1516 (GMT+8), full disc with exposure pushed to better show the prominences:-

1517 (GMT+8), with 2x barlows, AR1010 closeup:-

1519 (GMT+8), with 2x barlows:-

1520 (GMT+8), with 2x barlows:-

C5 + Cheapy-ERF + PST etalon + BF10 for the rest of the close up shots:-

1526 (GMT+8), more aperture shows more detail:-

1527 (GMT+8):-

1531 (GMT+8), AR1010:-

1532 (GMT+8), another shot of AR1010:-