Monday, January 26, 2015

20150126 Moon

Very poor sky tonight, just for fun.

First shot C5 at prime focus:-

The rest with 2x barlows:-

Poor seeing and transparency.

20150126 Sun, also testing of Canon 100-400mm f4.5-5.6L (first generation) on H-alpha imaging

Thank God that I can get another Canon 100-400mm f4.5-5.6L finally.

I sold my first one before the release of the second generation, but then my sister bought my a new 70D so I deadly want to get a longer lens to fully utilize its focusing ability, so with some very nice offering, I got one finally.

Given it has the same 77mm thread with my Ranger, so why not try it out on Solar imaging too?  To use the BF10, I have a EOS 1.25" adapter, but to reach focus, I have to insert a 2x barlows before the BF10.  Conventional wisdom gives an estimate with 3x, so the first shot was done at around 300mm effective focal length with the Canon set at 100mm.

The image quality is far from satisfactory.  At first I would guess it's nice to take lower power full disc shot of the sun, but it's no good indeed.

Without much hope but just to complete the test, I set the Canon at 400mm, that means it's working at around 1200mm focal length.  To my big surprise, it's as sharp as my Ranger!  Maybe even better, I don't know.  But it really shines!  Very fine detail could be resolved with great contrast.

Okay, the test is done, so I switched back to my Ranger.  To get a full disc, I've to take two frames and stitch them together.  Transparency is no good today.

Then a close up AR2260 with a 5x Powermate, giving effectively 2400mm focal length.  The first one was obtained by K3CCD, my usual software of choice.

But then since now I've ASI and thus I have SharpCap installed, so why not trying it too with my Lumenera?  K3CCD was a bit troublesome, even I upgrade from Windows 8 to 8.1, it requires me to re-do the registration.  And the author Peter seems not responding after one whole week.  So, I switched for SharpCap.

With the software assisted focusing, the image seems sharper. 

Drop frame is further reduced after removing some more software from my Eee PC.

The sky seems alright until now, maybe I shall try out 2014BL86 tonight after dinner?

Imaging should start at around 8:00pm or else it will be too low.

Sunday, January 18, 2015

20150117 C2014/Q2 at Tai Mei Tuk

Fooling around DSS without much luck, I get back to Registax!  This is the resultant image.

Canon 200mm f2.8 wide open, ISO 3200, 30s exposure, 20 frames stacked.

The sky was foggy, I couldn't even see the Polaris.

We had some observation with some church buddies, one said it's like sputum... we had my Canon 10x30 IS for the observation.


Finally reprocessed in DSS, an inverted version to show the tail:-

Friday, January 16, 2015

20150116 Sun

While people are taking images of C2014/Q2, I couldn't afford the time to go to darker sky.  I am sick today but taking images of the sun is far easier.

AR2259 at 5x:-

Close up of the above prominences:-

Thursday, January 15, 2015

20150115 C2014/Q2 Again

So bad that I was trapped in the city...

ISO 1600, 15s exposure, 200mm at f2.8, 30 frames stacked... the sky might be too bright, and thus the faint tail remained buried by light pollution?

Wednesday, January 14, 2015

20150114 Sun

Given the transparency sky and a half day off, why not spend a few minutes to capture our sun?

Close up of AR2259, taken at 1512 (GMT+8), 5x powermate:-

Seeing 4/10, transparency 7/10.

Urban Comet Observation C2014/Q2 Lovejoy

I went back home at around 11:00p, and then cleared up the tasks of the kids... checking homework, technical support, etc... I went out at 11:30p!

I simply can't go too far, so I go to the playground where I used to jog.  Along the way, I checked the sky when there are trees blocking the close-by street lights.  M45 is naked eye visible, M42 of course.  But I could detect the comet by scanning around M45.

When I was about to arrive the playground, I settled for several minutes in another dark corner but then nothing was detected.  So I proceeded to the playground.

I found a chair, sat down.  I found some thin cloud but why not?  Armed with only a Canon 10x30 IS and my mobile phone as star chart, I found that I could use the bull eye, and M45 as guide posts... soon I located the comet without doubt.

It's big and diffused, bigger than M31 in darker (Hong Kong) sky... and remember this is from bright urban sky!  I guess that I was detecting a hint of the faint tail, too.

I am so happy... you know why I insisted to go out?  I worried that the weather forecast might betray me!  So, take any chance when you have, don't wait!

I'll surely go out again tomorrow night, with a small telescope plus a camera for sure!

Saturday, January 10, 2015

20150110 Indoor C2014/Q2

Just setup and shoot, no time to process yet.


The RAWs were so bad, so given up!

Thursday, January 08, 2015

GP style dovetail and quick release plate

The GP dovetail is undoubtedly the de facto standard for small to medium sized mount.

Yesterday night, I realized that its dimension is not far from another de facto standard for the quick release plate of many generic photographic ball head.

This kind of quick release plate comes in many different length, and more importantly, they're far cheaper! 

I've ordered two therefore, to be used with my Ranger and even other camera lens. 

Both my Nexstar SE mount and my GOTO Mark-X are using similar dovetail saddle!