Monday, October 30, 2006


Today, I got 15 minutes only and I tested SM40/PST double stacking configuration.

SM40/Borg 45ED/PST etalon/BF10, double stacking on the cheap:-

16:01 (HKT) Close to full disc

16:02 (HKT)

16:03 (HKT) Full disc by drift method

16:05 (HKT) 2x barlows

16:06 (HKT)

Sunday, October 29, 2006

20061029 Solar Observation

This is done by C5/Cheapy-ERF/PST etalon/BF10.

The PST etalon is really very well designed, the afocal lens system does a great job in maintain the incoming cone to become parallel before feeding into the etalon. That maintains the bandwidth very very well, and also produce a very temperature stable system, since light are diverged to become parallel before the focal point, that helps a lot to reduce the heat reaching the etalon, I believe. For the case of a C5, light from 127mm is converged into a 15mm light cone, which is not too hot. If I put my hand at the focal point of the C5 after the Cheapy-ERF, I can feel the intense heat after 10-15s, however, since the bandwidth is well kept, I suppose the heat reaching the etalon should be way less, otherwise, bandwidth will be widen before the etalon breaks for the intense heat.

Enough said, time to show the pictures:

C5 2x Cheapy-ERF:

C5 + Cheapy-ERF at prime focus, this is the first clip processed by Registax V4 with 2 alignment points, no need to convert by VirtualDub any more, save a lot of disk access and disk space:-

Prominence merged with surface detail:-

Prominences from all part of the disc:-

Saturday, October 28, 2006

Large aperture observation

I borrowed a PST etalon from my friend and tried some experiments today.

The most exciting one is with a 6.5" ERF, but I only have a C5 on hand... so, my observation is done with 5"!!! This is definitely fun for H-alpha at this aperture!

First one, C5 full aperture at f/10, ~2000 frames stacked:

Close up:

Another close up, more carefully processed:


All of the prominences:

Sunday, October 22, 2006

20061022 Solar observation

The sky was pretty good, however, the image quality seems less than favorable, I guess there're still some problems in my OTA, either the tube or the focuser... Got to check out, but anyway, should be able to get some decent results.


1418 (HKT) Borg 45ED, 1.5x C mount teleconvertor, DMK 31AF03, SM40/BF10:-

1423 (HKT) Borg 45ED, 1.5x C mount teleconvertor, DMK 31AF03, SM40/BF10:-

1501 (HKT) Borg 45ED, 2x barlows, DMK 31AF03, SM40/BF10:-

Change of AR917 from 1434 to 1457 (HKT):-

Wednesday, October 18, 2006

Short solar observation and experiment time!

Took a few shots with my Ranger at 2x:

The relatively bigger prominence combined with the surface detail shot:

Another one:

Sunday, October 08, 2006

Solar followup

The sky was very bad today, very very large amount of thick cloud, I got this with 1/7s exposure, medium to high gain, after two shots, the sun was totally invisible any more.



20061007 AR913 AR914

Taken at 1301 local time, Borg 45ED, 2x barlows, DMK 31AF03, SM40/BF10:

Full disc, without barlows, merged with prominence frame:

A mosaic:

Wednesday, October 04, 2006

20061004 Lunar observation

C5, 2x barlows, DMK 31AF03, poor seeing (1/10) and poor transparency (3/10).

Took over 3000 raw frames by exploiting the 30 fps of DMK, stacked over 2000, might be improved by reducing the number of stacked frames, Vallis Schroteii:-

Limb near Calvius:-

Testing of new gear

The sky was pretty bad, it's more like to test of the new gear rather than to observe. My wife was on night shift and I managed to get Alby to sleep quite early, that's why I got a chance.

Tested the Cosmicar 150mm f/3.2, but the image is pretty soft, so I test it with the 1.5x teleconvertor too, so the effective focal length is 225mm at f/4.8.

The second shot is obtained by my C5 having the new dovetail at prime focus: