Monday, November 24, 2014

20141124 Sun

Sky condition very poor today, so I couldn't do anything else except a 2 frames mosaic as below as a record, no flat field:-


Taken at 1507 (GMT+8).

Sunday, November 23, 2014

20141122 Sun and experiment with flat field

The CMOS sensor of ASI 120mm is quite sensitive in creating Newton's ring.  I found it's pretty terrible in the last imaging session.  People suggested that Newton's ring could be removed by tilting but then it involves on more adapter and it's not really a good way indeed.

An alternative approach is to do a flat field which can remove the Newton's ring as well as any dust on the CCD.  A flat field could be acquired by de-focusing the image a large bit, and I found it natural for the whole work flow.  I normally do a prime focus shot, and then pump up the magnification by adding a barlows/powermate, and before I refocus with the barlows/powermate, I simply capture a flat field first!

First up is a mosaic of two shots, taken at 1151 and 1153 (GMT+8) respectively.


So, two shots were taken afterward by using the method above with a flat field.  The first one is done very close to the flat field, so the Newton's rings were removed completely.  It's taken at 1157 (GMT+8):-


Next one is taken at 1159 (GMT+8), I don't exactly know, but seems like the Newton's ring is not as cleanly removed as above.


There might be two reasons:

1. field rotation since I'm doing alt-az tracking with the Nexstar SE mount, I found it unlikely, however

2. the flat field was not done correctly, since the solar disc was not occupying the whole frame, so the flat field is only partial, some dark corner was not illuminated afterall

So, next time when I do a flat field, I shall move the camera to the center of the solar disc.

Friday, November 21, 2014

Home@Walnut Changes (again)

Formerly, this room was my playing room.  There is only a computer, and a store room of my equipments.  But then when my daughters have to learn piano, I need to spare some rooms and so I sold my C8 and downsized to a C5.

http://oldfield.sinaman.com/star/walnut/walnut.html

Recently, my daughters requested their own room, so I have to move out from this playing room altogether.  My faithful self-design computer desk with storage cabinet has to be thrown away.  Actually, the upper half had been discarded when the piano moved in but now the whole thing would be gone soon.

I'll need to find a replacement.  Last night, I've measured the window platform of my own room and I found that it was 42" (width) x 22" (depth)  and then I could make a cabinet as high as 16" without blocking the windows.  This cabinet will be tailor made to store all my existing stuff inside, and I will be taking photographs from inside by using my Nexstar SE mount there and there should be enough room.  However, I couldn't use my desktop PC to take images by then and I've to go back to my Eee PC which should suffer from much lower frame rate?  Maybe it's time to upgrade with a better computer?

Before it was killed, let's take a photographs in remembrance:


Top most level for my Camera gear which consists of a Canon 450D, a kit lens, a 50mm f1.8, a 8mm fisheye and a Canon 200mm f2.8L plus a Kenko 2x, a couple of manual macro tubes, shutter release, flash, etc.  And there are two new members namely the ASI 130mm and ASI 130mc.

On the second level is my trusted Ranger, my Mark-X, eyepieces and accessories box.

On the third slim level is my Canon 10x30 IS, and some miscellaneous stuff.

Finally, the lowest level is my C5, plus my Solar 60.

Monday, November 17, 2014

20141117 Sun (ASI 120mm + Sharpcap + Avistack)

This is a whole new combination.

At prime focus, it really shines at its first impression!  Most detail could be seen very easily.  After processing, it's even more wonder:-


Taken at 1205 (GMT+8), very impressive, not much processing required.

However, on going to high power (5x), the evil comes.  Newton's rings were very serious.  I've tried to remove that protective glass window, does not help.  And that introduces some dust too...


It seems like I've to try to add a flat field next time?

Thursday, November 13, 2014

ASI Cameras

What is better than an ASI camera? 

The answer is two of them!  I got myself an ASI 120MM and an ASI 120MC, the monochromatic model is for solar and lunar imaging, while the color one is for planets.  Frankly, with only a C5 as my biggest telescope, I believe that I will let the color one go soon.  But anyway, why not give a trial?  I had success with a DBK and a C5, so I'm pretty confident that the ASI will do the job nicely as well.


The general impression is excellent.

Packaging is simple but works.  It comes with a lens, a 1.25" nosepiece, a driver CD, a very nice USB cable, and you even get a ST4 cable!

Installation is SUPER EASY as mentioned in the user guide.

The software is easy to use, too.

--

The software and the driver are rather stable, but this is only my first impression.  Sharpcap is easy to use and pretty powerful.

I've to update my Registax 5 to the latest release to support the Mono8 codec, RGB24 is fine as expected, no need to upgrade.




These were pretty dark, I have to use very high gain and relatively long exposure (~1s) to get images like the above.  Not bad, I would say.  Not a huge improvement over my Lumenera nor DMK, but I should test again with astronomical targets.

These two cameras were again close to par-focal with my Japanese Widescan 20mm Type III, nice plus.

Expect better sky next week.

Wednesday, November 12, 2014

Selling my L070m



This has been my workhorse camera.  The only problem was the connecting cable from the USB side PCB to the lens side PCB, but it is fixed perfectly.

Comes with a DIY plastic case, the original lens, plus a C mount to 1.25" nosepiece.

Only ask for $111 USD paypal shipped.  Will be posted to cloudynights shortly.

Monday, November 10, 2014

20141110 Sun

Seeing 3/10, transparency 4/10, most cloudy.

Tow prime focus shots, with some tweaking on the T-max and RichView, also the processing style...  1422 and 1431 (GMT+8)



 Close up of AR2205, taken with a 5x Powermate, 1450 (GMT+8):-


Notice that these three shots were taken with some gaps in-between, this exactly shows the amount of cloud floating around.

Thursday, October 30, 2014

20141030 Moon

The moon is in front of my windows.

Aligned my C5 on the Nexstar mount, I found millions of drop frames... reboot does not help, replacing the USB cable does not help.  Eventually, the camera even black out....

So I pulled out my 450D, but then the balancing becomes an issue... tracking is inaccurate, and the mirror induced much shake to the system.  It's still alright at prime focus but then when I just up with a 2x, the 450D rotates around its adapter nose piece, and the shake is no longer trivial at 1/10s exposure even with a shutter release cable.

I disassembled the Lu055M and I guess I know what's the problem.  Put it back and it works again but then the moon is sinking quite low and cloud rolling in too!

First up is a moon taken with my Canon 450D through my C5, live view focus, manual exposure (a bit over), taken with a shutter release:-


This is my Lu055M being repaired:-


Next is another prime focus shot taken with my Lu055M, notice that this 1/3" CCD rendered a much higher resolution than the APS-C sized CMOS even both were taken at 1250mm focal length:-






Without much time left, I took another shot with a 2x barlows with my Lu055M:-


It seems like that Lu055M is dying?  Before its death, I will make good use of it!

Monday, October 27, 2014

20141027 Sun, another observation on AR2192!

From that prominence loop on 20141015, this is the 4th observation/imaging session on AR2192!  This monster has grown to the size from slightly bigger than our Earth to now bigger than Jupiter.

All time in GMT+8.

Prime focus, taken at 1428:-


5x, taken at 1430:-




5x, taken at 1433:-


Taken at 1436 to 1441 all with 2x barlows, 12 frames stitched together, I guess the focuser draw tube slips a bit so that the lower left corner has a gap:-


 2x close up of a long filament taken at 1442:-


2x close up of AR2192, taken at 1443:-


I will try to do mosaic later, but the Tmax and RichView must be more carefully adjusted.

Monday, October 20, 2014

20141020 AR2192

I've very limited time today, so I focus myself on AR2192.

First up is a prime focus shot taken at 1525 (GMT+8):-



And then two 5x shots taken at 1528 and 1529 (GMT+8) respectively, the second shot seems to contain more detail.



Seeing at 2/10, transparency 5/10.

I love this little mighty Nexstar mount, even at 2400mm, tracking is accurate enough for relatively long exposure.  Great for both indoor and out door purpose, I mean for high resolution imaging on planets, lunar and solar shots.

I just made another power source for my Nexstar, now it has 8x AA eneloop (9.6V) in its built-in battery compartment, and 3x 18650 Lithium battery (11.1V) connected via the external power socket.  Both works very nicely, and in case either one fail or exhausted, the other one will pick up seamlessly.


I've two sets (i.e. total six) unprotected 18650 batteries at home, so it's more than enough for a whole night of observation.

Saturday, October 18, 2014

20141018 Sun

Seeing 4/10, transparency 4/10.


First up is the prime focus shot, a few filaments on the surface, with one or two extended out to form prominence.  AR2192 is giving another long prominence upward.  Taken at 1235 (GMT+8):-


Then, we have two 2x shots, taken at 1237, and 1238 (GMT+8):-

AR 2187:-


AR 2190, this should be the active region which gives a big prominence loop earlier this week:-

I didn't go for 5x, i.e. 2400mm for pretty long.  Here we go, taken at 1241 (GMT+8) centering on AR 2190 and 1243 (GMT+8) centering on AR 2187:-



Quite a good day... if I have more time, I will do a mosaic...

Wednesday, October 15, 2014

20141015 Sun

Seeing 3/10, transparency 3/10, foggy sky but low humidity, severe air pollution.

We have a large prominence loop which is the best feature of today.

Let's look at the prominence shots first:

First up is a prime focus shot, taken at 1336 (GMT+8):-


And then the following were taken with 2x barlows:-

1342 (GMT+8):-


An overexposed shot taken within the same minute to show the darker portion:-


Finally, 1337 (GMT+8), another one on the lower half of the solar disc:-

  

Let's focus on the surface detail, prime focus taken at 1337 (GMT+8):-


AR2188 (?) taken at 1339 (GMT+8):-


AR2187 taken at 1340 (GMT+8), from this shot, it seems like that prominence loop was not coming from AR2187 but another big active region seems just around the limb, let's see.  But I probably won't have time to capture it in the coming few days.


Very nice observation today.

Please pray for Hong Kong, we had a very bad time these days, probably among in my life.

Saturday, October 11, 2014

20141011 Sun

Today, I used my Asus Eee 1005HA for image capturing since my Dell all-in-one PC was occupied by my wife.

My Eee has a new battery which allows over 7 hours of continuous usage.  Given it could be placed near to the telescope, focusing is far more accurate.  Drop frame is a must, but it's not a major issue either.

Seeing 5/10, transparency like 0-6/10.  We got quite a large amount of moving cloud, thick enough to block everything but we have some sizable cloud gaps.

First one was taken at 1233 (GMT+8), prime focus:-


Then, we have another one at 1235 (GMT+8), with 2x barlows:-

Finally, we have another one at 1241 (GMT+8), with 2x barlows, using drift and expand to allow bigger field of view:-

I'm being inconsistent in making these false colors obviously.

Thursday, October 09, 2014

20141008 Total Lunar Eclipse

Equipment Line-up:-
  • Mark-X with hand controller, 
  • Canon 200mm lens with 2x tele-extender
  • Eyepiece adapter, eyepiece, barlows, diagonal (not used finally)
  • Camera, shutter release
  • Canon 10x30 IS binoculars
  • Gitzo G106 with 410 head
Location: Tsim Sha Tsui, Avenue of Stars

Met some old astronomy buddies:-


 My simple setup:-






Mostly cloudy, the only successful shot was taken at during a cloud break of around 8s, but the exposure itself took 4s, so only had a few seconds for centering the target and focus.

The only successful shot, 400mm at f/5.6, ISO 800, 4s exposure:-



Some less than successful shots:-



I was captured by TVB:-

https://www.facebook.com/video.php?v=751378074897355

Tuesday, October 07, 2014

Asus 1005HA, Stellarium, Celestron Nexstar

I have bought a new 9 cells battery for my old Asus 1005HA Eee PC, and it allows more than 8 hours of continuous operation in a single charge.

Installed Stellarium into it, but I have to use the mesa version since the OpenGL support was too weak due to ancient hardware.  The frame rate is very low at less than 2 fps, but it's definitely useable.

That mainland made cable from taobao works very well, and the telescope control is trivial.  However, I don't really think I will want to use a PC outside, for the Nexstar hand control is good enough.

Monday, October 06, 2014

20141006 Sun

Transparency 5/10, seeing 3/10.


1247-1251 (GMT+8), four frames stitched together, with 2x barlows.

I guess I did something very wrong, the prime focus shot and the 5x barlows shots were very strange and has to be thrown away.