Tuesday, February 09, 2016

20160209 Sun

AR2497 and 2494.

Pretty good seeing, 1428 (GMT+8).  T-max tuning could be improved, however.

Bob's knobs ordered for my C5

Went out last night for Jupiter imaging, setup everything but found that collimation was off!

Too bad that I forgot to bring a screw driver.... no way to tune!

So, I ordered a set of Bob's knobs! 

I was tempted to buy compatible screws, but then I feel that I need to respect the original inventor!

I found my newly bought small camera bag could fit my C5 and the Gitzo G105!  The zipper pockets could hold eyepiece too!

I'd keep my C5 therefore.


Some day-back records:

A few days ago I took some solar images.

Two nights ago I went out for visual observation with my Canon 10x30, but then nothing could be seen except M42 and M45... M35-38 failed, M41 was suspected.

Last night was the Jupiter imaging session, failed badly.

Monday, January 25, 2016

20160125 Winter Sun (冰天的太陽)

Armed with a new focuser together with a clear sky, there is no reason not to shoot.

It's record breaking cold in Hong Kong, at 3 degree Celcius and strong wind, it's not bad to be able to shoot indoor.

First up is sun taken with crop mode, note the Newton's ring... 1403 (GMT+8):-

On using full chip mode, I could drift the sun around while capturing and that effectively remove the newton's ring, it's also much higher in resolution.  1407 (GMT+8):-

Click for full size.

Monday, January 11, 2016

A little adapter designed and 3D printed by a local buddy Jack Wong

The Skywatcher Sky Adventurer mount has a small polar scope illumninator, but then it has to be taken off before attaching the dovetail rail or a ball head.  It is not very convenient in the sense that 1) when the mount was moved accidentally, polar alignment could not be done without taking off everything 2) when attaching the telescope or camera, the setup might moved and then polar alignment has to be redone.

To solve this problem, a local buddy designed a small orange adapter and then 3D printed it so that the polar illuminator could be attached to the dovetail rail!

Sunday, January 10, 2016


I've been looking for a NGF-S or NGF-CM, but in vain.

Too great that I came across such a deal in CN classified, and better yet, the seller agreed to sell me because I had been active and helpful in CN!  It's not unexpected since there involves extra effort to ship overseas.

I'm excited, you know, this deal seems to be prepared for me.  That focuser didn't even come with a telescope adapter, not even for SCT, but I had one for my Ranger!

Solar imaging quality could be improved finally...

Finally got the tracking number, and it just left US last night:


expect to arrive Hong Kong in 6-10 days, i.e. earliest arrival could be Monday.

Saturday, December 19, 2015

20151218 Moon

Seeing was no good again due to the strong wind, it's not too bad as it will be getting warmer in a few days.

The moon was going to the edge of my observation window and thus I could only get this one, resolution lowered.

2018 (GMT+8), Ranger at prime focus.

Wednesday, December 16, 2015

20151216 Sun

Winter finally comes! Having said that, it means 16 degree Celcius only... it's going to drop to around 13 tonight, so wind is getting strong.

Rather nice transparency at 6/10, seeing 1/10 as created by the wind....

Reducer lens always inside the BF10 unless stated explicitly.

First up is an image taken with ROI feature, frame rate goes up to over 40 fps, but given the very poor seeing, it does not help much.  Taken at 1433 (GMT+8):-

This is what it called "skip" mode, full resolution is not used by skipping some pixels, which results in higher frame rate, but with the same field of view.

By using full resolution, the frame rate is lower and as you will see from below, the image is blurred far more by seeing.

So now the "skip" mode is even more useful than ROI. 

I found that ROI is not well implemented by SharpCap, it is not user friendly at all, one should be able to draw the ROI on screen instead of setting offset and the frame size!

Wednesday, December 02, 2015

The Dark Cube at Work: 20151202 Sun

After some experiments, the Dark Cube now works.  A reducer was used in order to fit the whole solar disc into a single frame, given it has 5M pixels, making it a bit small is still fine enough.  The reducer lens is just a 30mm binocular objective, dropped into the barrel of the BF10 so that it was sandwiched between the blocking filter and the camera.   The focuser drawtube of my Ranger was fully retracted, and the fine helical focuser has enough travel.

Seeing 3/10, transparency 2-3/10 with cloud around, so I only got around 200 frames to stack.  The T-max/RichView could be tuned more carefully if there was less cloud.

AR2458 on the left, a few small prominences around.

Taken at 1409 (GMT+8).