10-12-2011 Total Lunar Eclipse at Hong Kong

What a wonderful lunar eclipse! This is the first time I imaged the whole total lunar eclipse. I was so luckily that the weather was exceptionally good in Hong Kong. I enjoyed the total lunar eclipse for about six hours! However, due to lack of experience, my photos were not good. I did every in rush. Now after reflection I summarized the reason of these bad photos.

1. I pointed the scope to Jupiter and got it focused with the focusing mask. It is no good to use planets to do focus. They are extended objects, the diffraction spikes are wide. It is hard to make judgment whether it is in focus. It is by all mean pick a bright star to do focusing.

2. My scope was placed inside my car’s boot for an afternoon. I guess the temperature is around 20oC to 23oC that day. However, the average temperature while I took the photos is about 14oC and the lowest temperature was 11oC. I checked the focus at the end of the eclipse by pointing the scope to Sirius. It was out of focus! According to previous testing, the focal shift was about 6x7=42um (6 divisions in electric Feather Touch focuser and each division is about 7um displacement). So I should check the focus regularly, say every 30 mins.

3. During the whole lunar eclipse, the brightness of the moon varies a lot. In my case, I set the ISO to 800, the corresponding shutter speed varies from 1/4000s to 1/10s. In addition, I need to pick different exposures for selections later. Originally I set the interval of the programmable shutter to 1 min. I noticed that I need more exposure for selection in the middle of the imaging. It is luckily that I can still make it by doing bracketing exposures for every time intervals. So it is quite an involving job!

4. The shutter speed would be slow at totality, if the ISO is not high enough. In my case of ISO 800, the shutter speed was down to 1/10s. For tele-photography, one should use high ISO. So get a low noise camera and set high ISO.

24-10-2010 High Resolution Lunar Mosaic of 29 Pieces

I've been waited for full moon for more than half year since last encounter!

http://willisao.blogspot.com/2009/12/high-resolution-lunar-mosaic.html

Finally I made it on 24-10-2010!!! This is a resized version. The original size is 5261x4628. I wish I can break the world record one day.

http://www.lunarworldrecord.com/

Best 95% of 100 frames per avi files are stacked. HKT 01:00, 24-10-2010, Moon age 15.9, Equinox 120ED, Baader UV/IR, EQ3Pro, DMK41, Registax 5, PS CS4

High Resolution Lunar Mosaic

I did a quick imaging work in Christmas Eve because I needed to rush home for dinner. The seeing was 5/10 and the transparency was 4/10. Originally I want to shoot both Jupiter and moon. However I didn’t make it for the Jupiter. I used the Equinox 120ED and the 5X Powermate for the Jupiter imaging. The effective focal length was 4500mm. It was just too difficult for me to get the image on the DBK21 CCD. I tried for an hour and finally I gave up and switched fast to the moon. It was a good exercise for me to shoot the moon in high magnification. I used the Equinox 120ED and 2.5X Powermate. The effective focal length was 2250mm. It was longer than the focal length of C8. In order to save my work, I intentionally used more margins. I don’t want to ruin the whole image by miss a small parts of the moon. The final mosaic is a composition of 22 photos. I found it was difficult to make the sharpness uniform in all 22 photos. The underlining key is the selection of alignment points, not the number of alignment points and the wavelet. After process the image for more than 15 hours, I gave up! This is the result.

Click here for full size images:

http://wphoto.myvnc.com/24-12-2009_original.jpg

http://wphoto.myvnc.com/24-12-2009_original_bg_rotate.jpg

Moon age 7.9, Equinox 120ED, EQ3Pro, DMK41, Registax 5, PS CS4

Filled background and rotation applied

Reprocess the 28-11-2009 Lunar Mosaic

The previous lunar mosaic was not very good. Some parts of the moon were blurred. A quick reprocess of one of the avi file tells me that the problem arises from post processing. The problem was mainly due to the poor selection of the alignment points. After some experiments, I found that the optimal number of alignment points is 4 to 5. The location of the alignment points is also important. I cannot generalize the general rules, but it seems that both high and low contrast locations are important. If you want to reveal the details of the low contrast location, one needs to pick an appropriate location for it. So don’t just focus on those high contrast locations.

Moon age 10.636, Equinox 120ED, EQ3Pro, DMK41, Registax 5, PS CS4

Lunar Mosaic

Last night the sky condition was good. Both seeing and transparency were about 6/10. I went to the roof of my school and did observation and imaging. Since I needed to go to a wedding banquet, I did everything in a rush! I deliberately used the Equinox 120ED to make a high resolution lunar mosaic. The image was makeup of 4 images. This was the first time I made it! My next challenge is to use a 2.5X Powermate to make a lunar mosaic!

Moon age 10.636, Equinox 120ED, EQ3Pro, DMK41, Registax 5, PS CS4

The Lunar X

Yesterday after school, I was fed up with my work and I missed two consecutive observation days already. I don’t want to end up with sorrow and I don’t want to waste the clear sky. So setup telescopes quick and enjoy!

This was the first time I seriously use the new eyepieces, Baader Planetarium 8-24mm zoom, Tele Vue Nagler 3-6mm zoom and Tele Vue 2-4mm zoom. However, the instrument is nothing more important than the observation. I started the observation at about 6:00pm. The moon & Jupiter were hanging in the sky. When I pointed the M8 ACF to the moon, I quickly recognized the Lunar X. This is the first time I saw it and I remember that it can be seen in certain moon phase. However, I must good home because my two little daughters were waiting for me. So I packed all the telescopes and went home. I thought I can take the Lunar X after dinner.

After the diner and father’s evening duties, I started to image the moon at about 10:00pm. Oh Gosh! The Lunar X was not as obvious as that at 6:00pm (Moon age 7.615). It was stand out at 6:00pm, but now it was pale. I did everything in rush. Finally I made it! After that I search the Lunar X information in the Internet. The Lunar X can only be seen in 4 hours just before the quarter!
http://www.astropix.com/HTML/SHOW_DIG/097.HTM
Lucky me! I made it! My next challenges are high resolution lunar mosaic and high power magnification lunar features.

Moon age 7.781, Equinox 80ED, DMK 41, Porta mount, 482 out of 500 frames stacked, Registax 5, PS CS4

Lunar Image Taken with Equinox 66ED

Home observation again! Apart from the clouds running around, the seeing tonight was quite good. This lunar photo was taken by a small refractor Equinox 66ED and DMK41. Without much stacking skill, the result is follow:

Equinox 66ED, DMK41, best 442 frames stacked

Equinox 66ED, DMK41, 500 frames stacked

Afocal trial

Today is a happy family day. After coming back from the Kadoorie farm, I took a wonderful shower. Ah…the half moon was just hanging outside my window. I used my grab-and-go scope, ETX-70, to do lunar observations. This was a good chance to test the Sky-Watcher’s 8-24mm zoom’s afocal ability. A friend of mine found out accidentally that after removing the eyecup at the back, it is a standard 42mm thread. I bought a 42mm to 52mm adaptor, which enables joining my good old Olympus C-5050 to the zoom eyepiece. The C-5050 has been sitting in the drawer for a few years. It is bulky, but its optics is good amount it’s class. That’s why I still keep it. It time for it to work again! The photo is a single shot. Is it OK to you?

ETX-70, Sky-Watcher 8-24mm zoom eyepiece, afocal, Olympus C-5050, BW, ISO200, F2.6, 1/200s