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:-

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:



Prominence:



All of the prominences:

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.

Pending.

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):-

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:

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.


1641

1642

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:

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:

Solar observation

The sky had been bad for so loonngggg... finally got some clear sky, not very good, but at least do-able for some limited imaging.

Photographs:


15:22, overprocessed disc, but it matches the prominence frame nicely, also uneven illumination is minimized.


15:32, this one is way oversampled, 5x barlows used with Borg 45ED, but at least it told me that at this image scale, the amount of detail is superb. All dust revealed due to the excessive magnification.

Very brief solar observation and test

Tested to scale up with the Kenko teleconvertor, it fails entirely and the solar disc couldn't be focused sharply, due to the very poor optics of the teleconvertor. So, the concept is not a problem but the implementation due to the poor lens. Sounds like a good telescope with a good eyepiece is a better bet.


1420

1421

1422

1423

Cloud covered very soon, hope I will be able to pump up the power to take some closeup active region shots!



I got it finally, but the sun was too low, poor seeing and transparency.

Also tested is the webcam trick, but the image is too bad for even pointing.

Partial Lunar Eclipse (followup)

The equipments for the first set of images and another series taken by DC:

Selected Photographs of the Partial Lunar Eclipse

Since it's cloudy, exposures are not always accurate, here's the set of image where the cloud were thinner and thus closer to reality:


03:36 (HKT)

03:39 (HKT)

03:44 (HKT)

03:49 (HKT)

03:49 (HKT)

It's harder than I thought: when there's cloud, it's hard to adjust the exposure to correctly record the shadow of the Earth from the moon, since it's hard to distinguish between shadow of the Earth and shadow of the cloud. Also, cloud would be moving all the time with variable thickness.

Anyway, it's a nice experience.

20060908 Partial Lunar Eclipse

Full of cloud cover, thin and thick, but still observable... However, that makes some of the detail lost, and the shadow of the Earth was not well captured, since some of the photographs were underexposed, making the shadow larger than it should be.

To address this issue, I intentionally overexposed a few shots, to see which part of the lunar disc is really black, or just a effect of cloud and underexposure.

All shots are taken with Borg 45ED, DMK 31AF03, no tracking. Thus it is an example to show field rotation as well.

more photographs pending..


02:36

02:50

02:52

02:58

03:01

03:02

20060903 Solar

Cloud never went away, but sometimes it's sufficient thin enough to form image in the focal plane, here's one of such shot, very short time window for capturing, no time to capture prominence, boring disc, people said 904 might come back, but this shot shows no hint of it:

20060902 Moon Observation

It's more like a test of the gun shot, to test my Borg 45ED in its new OTA, the moon was very low, deep yellowish and can be called orange indeed.

Same shot, at prime focus, DMK 31AF03, different processing style: