Monday, May 16, 2016

Nexstar 4/6 SE mount power comsumption

I bought a small USB power meter, and I sandwiched it between my USB power bank, and the USB -> 12V cable which is connected to my Nexstar 4/6 SE mount.

It was drawing 0.51A at 5.14V which is less than what I imagined.  When both motors were slewing at maximum slewing speed, it measures around 0.8-0.9A only!  Therefore, a USB power bank should be enough for a whole night of observation.

Fixing the Sky Adventurer

My Sky Adventurer was getting harder and harder to turn... it was kind of stuck even if you totally disengage the clutch, it won't turn unless you really force it.

On opening it, the problem was nearly shown, see below:

there was a circular scratch mark on the inner rotating axis!  Obviously, it shouldn't be there and it should be caused by some metal dirt or uneven machining?  So I cleaned up the surface and found a few small marks, they're so small that even if you touch them, you won't feel there's anything... I bought the finest sandpaper to sand those stuff down, and then put the inner axis in, rotate it a few times, and there are two dirty patch will form, and then I sand them down again and again.

Finally, they were gone.

You couldn't trust your finger, you won't feel it.  But if you turn the inner axis with it, dirt patches will form.  So after a few runs, they were all gone!

The gear was not machined very nicely, and I sand down those rough edges like the one which is shown below:

Placing some grease back (thank Eric Ng), and now it's very smooth!  The machining is not bad afterall, when I put the inner axis back even without grease, it feels like pressing a syringe! 

I'll them it along for camping and stargazing trip soon!

Thursday, April 07, 2016

20160407 Sun (visual)

Thick cloud floating around...  so it's good time for testing my Canon 18x50 IS plus my newly DIY baader filters.

The rings were two 52mm-58mm stepping ring with 58mm male thread.  52mm is about right given the 50mm aperture of the Canon, and then 58mm would be perfect with the Canon, too!

The Baader filter was removed from my DIY filter previously for my Canon 10x30 IS... I won't use the Canon 10x30 IS for that purpose given I've the bigger brother.

Image stabilization works great, and I can detect the tiny 2528 without looking at on the first hand.  Sounds quite nice.

Suddenly, I remember that I had used with Canon 10x30 IS for my total solar eclipse trip!

Monday, March 28, 2016

Removing all advertisements

There is not much earning possible with this blog.

Thus, I've just removed all the advertisements, inline or banner, links or whatever, in order to provide better browsing experience.


Sunday, March 27, 2016

20160326 Sun

The sky cleared up, with seeing 4/10 and transparency 7/10.

Sharpcap upgrades again from 2.7 to 2.8 this time, and it's apparently faster.

Taken at 0453 (UT), using the "skip mode", i.e. to skip some pixels in order to burst the frame rate at the expense of lower resolution:

Another one at 0523 (UT), using near full resolution (crop a bit), the frame rate is much slower, and it might result in some field rotations... a much bigger file (nearly 9G of data), but high resolution full disc shot in a single capture!

Wednesday, March 23, 2016

A new member

I always love my trusty Canon 10x30 IS, it's so portable and powerful... even its rubber coating was damaged by the DEET a few years ago.

I got a good deal recently on a Canon 18x50 IS!  I had always been looking for something like that, for example, I suffered from a broken Canon 15x50 IS before from ebay which costs me the return shipping cost and so much frustration!  Finally, this is a local deal which is about perfect!

IS works very nicely and with the higher power and the heavier weight, I expect it won't be as great as the Canon 10x30 IS for the stability, but the added aperture, and the far higher power is going to shine!

Longing to use it in the field!

I guess it will be a great partner to be used with wild camping trips.


2016/3/27 night:-

The sky cleared up a bit with transparency 3/10, I picked it up for some scanning from inside my home.

I saw nothing when I pointed it to the muddy sky.  However, after engaging the IS, stars popped up from the view, and the stars are pinpoint!  I could see the subtle color differences between stars, but then there is no chromatic aberration except on a few brightest stars, but I suspect they might be from atmospheric dispersion or effect of poor seeing.

I am pleasantly surprised by its optical quality.  High power scanning with image stabilization is just fantastic! 

Wednesday, March 09, 2016

20160309 Partial Solar Eclipse

My original plan was dull and boring, i.e. making high resolution H-alpha eclipse shots.  But the sky was so bad earlier this morning rendered this plan impossible.  So armed with my Canon 70D with a 100-400mm lens, and a 20 years old thousands oaks solar filter, what can I do?

I did a field trip yesterday night to see whether the location is suitable or not.

And this was how it looks this morning:-

Gave up? Not yet...

At 0814 (GMT+8), I first saw a hint of the sun...

Then at 0821 (GMT+8), it was even better

Soon I realized that I could take some images which clear sky would not allow, this was taken at 0844 (GMT+8),

Another mug shot at 0835 (GMT+8),

The sun was climbing up, taken at 0844 (GMT+8),

The sky was once cleared enough so that my filter must be used, taken at 0857 (GMT+8),

More shots with terrestrial object at 0920 (GMT+8),

Another one at 0922 (GMT+8),

The last one at 0954 (GMT+8),

Something that couldn't be done with great sky...

Monday, February 29, 2016

20160229 Sun

This is a special date, once in four years.  This is a special holiday for my daughter, and so I go out to have lunch with me.  So, I missed the normal observation time window.  By then, I can move my equipment cabinet in order to open the window of another side to capture the sun.

Using "skip" mode  which results in faster frame rate at the expense of lower resolution, 1539 (GMT+8):-

Using full size mode results in very low frame rate, but no need to do mosaic, alternative coloring scheme, 1546 (GMT+8):-

Teclast x98 Air 3G

A couple of months ago, I've backup the android partition and removed it.  The built-in drive is much faster than the micro SD (despite I've bought a faster micro SD) and therefore, much better for image capturing for the Sun and planets.  However, it has very limit space... in order to maximize the size, today I decided to remove all android related partitions.

To further free up spaces, I've mounted the micro SD to a NTFS folder and then moved the dropbox folder there.  So, I will have around 10G more space.

This is to prepare for the partial solar eclipse, as well as future imaging requirements.