Saturday, November 30, 2013

20131130 Sun

Call me a fool, I tried to overexpose the sun to scan around to see if I could detect ISON... of course I couldn't, but there is no harm and no cost.

The side effect was a sun image at prime focus:

Taken at 1224 (GMT+8).

Friday, November 22, 2013

Alternative power for my GOTO Mark-X

I've made a USB power interface with a broken extensible mouse cable previously:

And it works so far.  Under strong sun light, however, the solar battery will deliver from the solar panel directly and the current is not stable for that case.  Also, I found the solar battery might actually drain itself when the ambient light level is insufficient for charging!  Therefore, I want an alternative power supply.

For that matter, I've bought a couple of 18650 Lithium battery.  When two of them are connected in series, we have 7.4V which is enough to drive the system.  At 2400mm, this is more than enough for a whole night of tracking with just two.  And I've bought four of them, so it's more than enough!

The USB solution was kept in place.

And the dual 18650 batteries were sneaked at the back of the hand controller.

After testing, one set of batteries (i.e. two of them) could last for over 20 hours.  I've four on hand and thus it is sufficient for any purpose.

Thursday, November 21, 2013

20131118 Sun

Tele Vue Ranger, Baader 3.8 with Generic Green filter, tracked with GOTO Mark-X.

At prime focus, 1600 (GMT+8):-

With 5x, 1613 (GMT+8):-

With 5x, 1616 (GMT+8):-

My Lumenera Lu070M is dusty.  I looked at the sun briefly with the 4mm at 120x, not bad.

Friday, November 15, 2013

20131114 Moon

Tele Vue Ranger with 2x or 5x, Lumenera Lu070M at low gain.  Transparency 7/10, seeing 2-3/10, tracked with GOTO Mark-X.

Two frames stitched using autostitch, 2344 (GMT+8), with 2x barlows:

One more taken with 5x at 2348 (GMT+8), picked ~700 frames out of 3000, pushing gain to medium to allow faster speed to freeze seeing, most detail were still washed out:

I've pulled out my 4mm to watch for a while, the adjustable eye-cup is effective.  This is not an easy to use eyepiece, however, but not a problem to experienced observer.