Monday, March 31, 2008

DMK 21AU04.AS coming!

I was told that the camera is so popular that I've to wait after the next production run.

So after a few days, I received an email from fedex that my camera is actually coming! I'm sure that I'll keep tracking it every morning or so!

I'm eager to know how fast it will run on my old Sony Vaio U3 subnotebook with the USB 2.0 PCMCIA card, frankly, if it could go as fast as 15 fps, I would be pretty satisfied. And I guess it could go at full 60 fps with my desktop PC, since my DBK 21AF04.AS used to attain this speed!

What's so nice is that, it would not require external power for notebook usages, maybe this one would be with me during my total solar eclipse later this summer.

60 fps is going to be very powerful for the sun!!!


Sunday, March 30, 2008

Cloudy day again

We got all cloud today, no more followup shots can be done. I've downloaded the shots from my DC taken yesterday:

It's showing the C5/PST setup with newly designed Cheapy-ERF mounting, it's now far more secure than before:-

As told in the entry yesterday, the sun was drifting westward pretty quickily, and I marked the location of the sun just around 1 month ago, it will soon move to an even more westward making the C5/PST setup unable to point at the sun, but my Borg 45ED II could still do the job since I can always mount it via a longer dovetail plate, to place it outside of the window, since it's short and light weight - safe enough to be mounted like this and light enough to be mounted out of balance:-

Saturday, March 29, 2008

20080329 High resolution Sun

For high resolution, I mean the instrument only. But the sky is not cooperating, so the resolution is not really that high, at 1250mm effective focal length and the resolution with 5" aperture. C5/PST with my latest re-designed Cheapy-ERF mounting. Too bad that I found the sun was shifting west so I think it will be out of sight from inside my home.

1531 (GMT+8), AR987:-

1532 (GMT+8), AR988:-

1538 (GMT+8), AR989:-

1540 (GMT+8), a prominence:-

Finally, I have uploaded the video to see what the images looked like in real time:

20080329 Sun with Canon 10x30 IS

After the imaging session, I took my Canon 10x30 IS mounted with Baader film to have a look.

They sunspots were very fine visually, they're big even at 10x.

Without turning on the IS, I can see 3-4 spots, and with the IS, I can definitely see 5 of them.

My 987/988/989 finally!!! 20080329

Telescope: Borg 45ED II
Camera: DMK 31AF03
Close up with Tele Vue 2x barlows

On the camera issue: I've swapped the PCI slot for the Firewire interface and the problem gone! I guess it solves a software issue on the hardware, since by swapping the PCI slot, Windows XP recognized this as a new hardware and so the drivers are re-installed.

Back to the solar imaging session, first batches are in H-alpha, taken with Coronado Solarmax 40 with BF10, close up with 2x barlows:-

1252 (GMT+8), surface detail:-

1254 (GMT+8), prominence:-

1257 (GMT+8), surface detail + prominence:-

1259 (GMT+8), surface detail closeup mosaic:-

1252 (GMT+8), prominence close up:-

Next batch is in white light, taken with APM Herschel Wedge, with ND3 and polarizer:-

1315 (GMT+8):-

Finally in CaK, taken with APM Herschel Wedge with polarizer + Baader CaK filter:-

1320 (GMT+8):-

1321 (GMT+8), close up:-

Seeing was very bad at 3/10, transparency from 8/10 to sometimes 0/10 due to floating cloud, those cloud was pretty fast.

Monday, March 24, 2008

Cheapy ERF mounting solution (final)

I added three elastic strings to create a set of removable fixing for the Cheapy ERF to the visual back end.

Saturday, March 22, 2008

Several $8 HKD components for the autoguiding project

First is a SPDT switch. With two of them working together, we can control a motor to move in two different directions. So, I bought four of them to control both RA/DEC.

Next is a RJ-12 socket, this is the socket for autoguiding.

Signal from this socket will be feeded into the L298 motor kit to control the motor, actually, I can also build another hand control box with simple on/off switch with the L298 motor kit.

Wednesday, March 19, 2008

Upgrade path for solar equipments

The new offerings from Lunt's are very attractive for sure.

Right now the weakest link in my inventory is the bandwidth of my CaK filter, it's too wide that it's just better than plain white light view. No prominence in CaK is possible with that filter, and the constrast for CaK feature is also not high enough. Going for the new Lunt's 60mm CaK will definitely helps in terms of bandwidth. At the same time, I can sell my Baader CaK to pay part of the difference in price.

However, the Baader CaK is not without its advantage. Its resolution can be pushed by using a bigger refractor together with my APM Herschel Wedge. Right now the easiest accessible refractor is my Ranger which is 70mm in side, the Sky 90 could also be used but it's more in my friend's home. If I upgrade to the bigger refractor say a Borg 101ED or a William Optics 110ED, I can get higher resolution with it. And at the same time, the white light view will be improved at the same time. And of course, the bigger refractor will also be useful for some short exposure astrophotography (lower priority for me since my portable mount is a TG-SP II which is not enough for either refractor), and the bigger refractor will also help me to get better visual experience for planets and DSOs, a step above my C5. However, these refractors will not be easily useful for H-alpha since they're pretty fast.

In terms of H-alpha, I believe that I'll spend more effort in my C5/PST based setup first since it has the largest affordable aperture for me. In terms of bandwidth, maybe buying the 50mm model to double stack with my existing SM40 might be okay, however, it should not be way lower than my SM40/PST combination which is 0.6A already. Even two matched SM40 will give me 0.5A, so a 0.75A Lunt's 50mm and a non-specially matched SM40 will not give me 0.5A, so it makes no sense to do that. Going for a Lunt's 75mm might be good for aperture and bandwdith, but then it's not as narrow as my SM40/PST combination, and it's not as big aperture as my C5/PST. Therefore, it's not the best solution unless my C5/PST combination fails, however, the bottom line is, even if the internal reflection problem still persists, the resolution of the C5/PST is still high enough to win the Lunt's 75mm. I guess the 100mm Lunt's scope could be a good and sensible route, but then it's a bit too expensive.

So, the question is CaK only at this stage. Whether I want narrower bandwidth, or higher resolution.

Sunday, March 16, 2008

Sun and Moon in the eyes of kids

On the way back home, my little daughter saw the sunset for the first time. She's so amazed by the red disc in front of her, and then she turned to me to ask me a question.

Before quoting her question, I'd like to give a little bit more background first. She's 2 years old now, and in the pre-nursery class, she's in a group called "sun", and so she has a special interest about the sun.

So, what did she ask? She asked me why the sun got no eye! In the school, the sun got eyes and mouth, but the real one got none of these. Funny, right?

And then we're about to arrive home, my elder daughter realized that the moon was "following" her when she's walking, and then she asked.

My wife always said that I'm very successful here, since my daughters always keep looking up.


My little daughter also said, the moon got eyes, but my elder daughter said those were gray patches only... imaginations!

Saturday, March 15, 2008

20080315 Borg 45ED II Moon

Sky improves, I mean the transparency got pretty nice at around 7/10, seeing still rather bad like 2-3/10.

Telescope: Borg 45ED II
Barlows: Tele Vue 3x
Camera: DMK 31AF03.AS
Exposure is 1/15s and gain is like ~450.

This is a mosaic of the terminator, please click for full size.

Then I took off the barlows, and did a full disc shot, similar setup with my day time solar imaging setup, just without the H-alpha filters.

Finally, I had a look with my Japanese Widescan Type III, the moon is very sharp and contrasty without any color error around the lunar disc, I would say it's very close, if not a real APO despite it's just an ED doublet. Actually, a small objective like this at f/7+ is not hard to be a real APO.

Modified cell for our Cheapy-ERF

The former one is good in design but poor in execution due to a poor record of the correct measurement. Now, I found that it's better to have a more secure cell than the last design which uses only two very short stopper to hold the heavy filter in place.

Without a rolling machine, I have been thinking of ways to make a cylindrical cell. Finally, I found that with the last ring style mounting, I could actually use slightly longer screw plus some paper (just as light shield) to form a cell.

Of course, this is not a very good fit, and I will be adding some safety string to lock the filter in place while using. However, I found that even without any safety string, the filter will not be dropped even when the scope is pointing horizontally to the ground, and that's more than enough for actual usage as a scope will not be pointing anything lower than horizontal level.

I consider this the final solution for the mounting of this Cheapy-ERF.

20080315 Sun (very poor sky)

Today the sky is even poorer, I mean the seeing is really bad like 1/10, everything is very low in constrast, and the transparency is bad as well, like 2/10, and thus no meaningful detail can be acquired. At the same time, the sun is very quiet, nearly no prominences, and nearly no surface activities except a few short filaments, and some bright patches.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40 with BF10
Camera: TIS DMK 31AF03.AS

1250 (GMT+8):-

1252 (GMT+8):-

Friday, March 14, 2008

20080314 Sun (last bit of)

Cloudy, but I managed to catch the best moment. Just a record.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40 with BF10
Camera: TIS DMK 31AF03

1327 (GMT+8):-

1328 (GMT+8):-

Mounting screws found

TG-SP II Autoguiding Project:-

I just found that the mounting screws for my newly acquired 5V 6RPM DC Geared Motor matches exactly with the screws inside my computer acccessories box. Those screws were used on mounting hard drive, CD-ROM, or even the back panel, so I've a lot of them. Feels like they're M3.

However, I found that they're still different, and I found those which match the best with those on the motors.

So next I will need to buy a small plastic board to mount both motors there, and then look for a RJ-12 socket for autoguiding interface, the L298 will be mounted there as well. The last part of the integration will be to find a small plastic box to hide everything inside.


Also I believe that I've come up with a way to mount my Cheapy-ERF as well, it's just a matter to buy a couple of longer matching screws to make a cell with the existing mounting plate. Let's see how it works out.

The size of the screws should be M2.5

Thursday, March 13, 2008

20080313 Sun (cloudy)

The sky is so bad. I'm on leave today, together with my wife, and my kids are on leave suddenly as well...

Two AVIs taken around 1520 (GMT+8), note the prominence around the top right corner.

One of the frames extracted and pushed:-

Wednesday, March 12, 2008

20080312 Astrophotography through the gap

When I back home, the sun already sank below a close by building. Yes, I used to do astrophotography from inside my apartment through an open window. This shot shows my astrophotography style very well, and I named it "astrophotography through the gap" or in Chinese "狹縫中的天文攝影".

This is a kind of attitude in which:

1. you have limited equipment: I only use a small telescope (45mm aperture), with a small filter (40mm aperture), a very cheap mount, and a slow PC (6 years old!)

2. you have limited space: I only shoot from inside a small window

3. you have limited time: I need to work, need to spend time with my family, I have part time studies, I have...

but I also have a life time passion on astrophotography, so I catch every little chance while I can.

1721 (GMT+8), stacked:-

1721 (GMT+8), single shot from the same AVI:-

Tuesday, March 11, 2008

20080311 Sun (a bright spot)

Seeing poor at 2-3/10, transparency like 3/10, heavy white haze.

Telescope: Borg 45ED II
Camera: DMK31AF03
Filter: Coronado Solarmax 40 with BF10

1511 (GMT+8), this time, I've under exposed the image a little bit to spare space in the dynamic range to take care of the uneven illumation due to the sweat spot and internal reflection of the etalon, the best result ever!

1512 (GMT+8), prominences... notice that there's no prominences near that bright spot:-

Close up with 3x barlows, 1515 (GMT+8):-

Finally, I have a look with my highest dynamic range device, i.e. my eyes, with my binoviewer... the white spot is very nice, very much brighter than the rest of the sun, it should be a solar flare, I can see a little bit of "thing" rushing up from the solar disc. A very nice view.

There's no white light feature when looked with my Canon 10x30 IS with Baader filter.

Followup observation in 1544 (GMT+8) shows that the bright spot is now dimmer, but still very noticeable.

Remarks: it seems like it's AR985...

Finally, my setup:-

Monday, March 10, 2008

Unicap on Ubuntu

To have Linux support for your 1394 TIS DMK, DBK or DFK, you need this software:-

And they have a very nice instruction to show how to install it for Ubuntu:-

And you may also want to have a look on this page:-

Sunday, March 09, 2008

Problem found on my DMK/DBK

Recently, I found that there's a problem in my DMK, and in order to see whether it's hardware issue or not, I tried my DBK as well and I found the same problem. In this case, two simple photographs show how:

Normal frame:-

Frame with error:-

Those problematic frames consist of around 0.1% of all frames. However, it's annoying enough for it will confuse Registax. Then I tried to connect the DMK/DBK without the 1394 hubs, problem persists. And then I tried to connect them with another 1394 cable, problem again. Finally, I tried to use another PC, the problem gone.

That means it's not hardware problem of my DMK/DBK. Next, I tried to use the same PC but with Linux instead of Windows, the problem was not there... that means it's also not the hardware problem of my first PC. Therefore, it should be software problem, and it's on the platform, i.e. my Windows XP.

I then tried to re-install IC Capture and the camera driver, again no luck. Re-install some major codec, problem persists.

Still figuring out why...

20080309 Sun

Again boring sun, seeing is like 5/10, transparency dropped to 3/10, milky white sky.

Telescope: Borg 45ED II
Filters: Coronado Solarmax 40 with BF10
Camera: DMK 31AF03

1519 (GMT+8), this full disc shot is taken with faster exposure than I usually do, this leaves some room for manipulation, to clean up the sweat spot uneven illumination:-

1521 (GMT+8):-

1522 (GMT+8), exposure pushed to show the dim prominence:-

Saturday, March 08, 2008

20080308 Sun

I was too slow to catch AR984 before it disappeared from the western limb. The whole solar disc becomes boring again with a few small prominences around. Seeing 4/10, transparency 5/10.

Telescope: Borg 45ED II, NGF-S as usual but without extension tube for a 0.5x binoviewer corrector is attached to the DMK nosepiece via a small extension tube

Camera: DMK 31AF03

Filter: Solarmax 40 with BF10

I added the reducer to test under lower image scale, to see if the sweat spot issue can be reduced or not. And it also helps me to see if I can get a full disc sun in a single shot with my coming DMK 21AU04. So given this purpose, I digged out my DBK 21AF04 to try as well, for it has the same chip size.

1323 (GMT+8), seems like the reducer lens is not in good collimation:-

1324 (GMT+8), again, not as sharp as it should be:-

The following two are taken with a DBK 21AF04:-

1330 (GMT+8), notice that the Bayer matrix is killing the resolution:-

1331 (GMT+8), signal leakage causing the strange coloration of the solar disc:-

Friday, March 07, 2008

Binoviewing eyepieces

I've intensively tried three different sets of eyepieces for binoviewing, and they are:

1. Japanese Widescan Type III 20mm: they have decent eye-relief, very comfortable without glasses, no kidney bean distortion so that they are very easy to view through. They have more than 80 degrees field of view and one can see to the field edge without problem. They render good image but the field edge could become soft, and the light throughput can be better.

2. Japanese Orthoscopics 18mm: they have good eye-relief too, and very easy to view through but since they didn't get an eye cup, ambient light will affect your observation and it also makes them a little bit hard to hold the view. These eyepieces are extremely sharp, really excellent for planets, moon and the sun. But the field of view could be a little bit limited for deep sky objects.

3. Tele Vue Plossl 20mm: they are very comfortable to look through, they're extremely sharp and the eye cup is very well designed, their field of view is wide enough not to be frustrating, of course, I guess 60 degrees+ should be even better.

Over the years, the 18mm Orthoscopic pair is used least, mostly due to the absence of good eye cups. The Tele Vue Plossl pair used the most, since it's sharper and more contrasty on planets, the moon and the sun, and they have better light throughput for deep sky objects, too.

Thursday, March 06, 2008

Finding M41 from inside an urban apartment

A few years back, I can spot M41 on better nights from inside my home. So, I tried again for the last couple of days, they're not the absolute best in terms of transparency, but I just keep trying, I rated them as 5-7/10.

My tools include a pair of Pentax 10x50 PCF III, and a pair of Canon 10x30 IS.

Both couldn't detect it.

However, since the target is so close to Sirius, it then becomes a test for the optical quality of both binoculars. The Pentax has a smaller field of view, despite it's also 10x but it got only 5 degrees true field of view, the Canon is noticeably wider.

The Canon is sharp across basically the whole field of view, but the Pentax despite having a smaller field of view, star begins to show coma near the field edge. The Canon wins here.

The Pentax has a bigger exit pupil, but in urban area where you pupils cannot dilate much, the bigger exit pupil does not translate to a brighter image, but I guess the Pentax will show its edge, I mean the bigger objective, in darker locations.

Finally it's the chromatic aberration. The Canon is simply cleaner, the Pentax has noticeable purple fringe around Sirius.

Since I've been using my Pentax for so many years, I can hold it very steadily, and it approaches the Canon with IS engaged. Without IS, the Canon shakes but the Pentax can be held far more steady.

Wednesday, March 05, 2008

20080305 Sun

I am on sick leave today, but that does not stop me from having a short look. Setting up everything inside home is not a hard job anyway, and it took some time for the medicine to take its sleepy side-effect, so I asked myself, why not have a look?

Seeing is very bad at 2/10, transparency 7/10.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40/BF10
Camera: DMK 31AF03

Today, I tried to use slightly less exposure than I would use normally, to see if that helps to reduce the sweat spot issue during processing - leaving some room for me to stretch the curve could hide the sweat spot better, let's see how it works out.

1322 (GMT+8), it seems like it's not as serious, but I guess I can push the exposure a little more, try it next time:-

1323 (GMT+8), those prominences are very nice to look at with eyes, but I'm not skillful enough to capture them:-

Due to the poor seeing, I didn't use a barlow. And I also take out my APM Herschel Wedge plus the Baader CaK to take a simple full disc CaK, of course, nothing special there since there's no active region on the surface. Two different shots, with two different style of processing:-

1327 (GMT+8), you can see some activity near the top:-

1328 (GMT+8):-

Finally, I also took my binoviewer out. I immediately missed this feeling, visual observation is always the king, no photograph can reproduce such a feeling at all. There's less contrast, but the prominences are never as great as seen with my eyes. I promised myself to observe more with my binoviewer from now on.

Monday, March 03, 2008


Check out this link:-

also reported here:-

Hey, I just received an email notification that I have won the lucky draw from TIS, and the prize is a DMK 21AU04.AS. Actually, I was thinking about buying a new notebook which has a 6-pin 1394 interface to have a quick setup time for grab-and-go imaging, but now since this camera is running on a USB 2.0 interface, I guess that I can save some money now!

I will want to compare it with my existing DMK 31AF03.AS

The new one will have 60fps at lower resolution, and the chip size is also small so that I will need a reducer to get full disc image in a single shot.

However, it also got slightly bigger pixel size and that could be nice as well.

Smaller chip size might help in the sense of sweat spot issue in H-alpha imaging, and for C mount lens imaging, it should also help to keep down the aberration near the field edge, but of course, it will be as good as if I crop the image of my 31AF03 so it's actually nothing better.

Really hope to receive it asap.

Sunday, March 02, 2008

20080302 Sun

The sky is still pretty good, at least there's no thick cloud floating around. Seeing at 4/10, transparency at 6/10.

Telescope: Borg 45ED II
Filter: Coronado Solarmax 40 + BF10
Camera: DMK 31AF03
Barlows: Tele Vue 2x barlows used for closeup

Again the sun is rather quiet, but there's a nice long filament, and a couple of small but nice prominences around.

1451 (GMT+8), at prime focus:-

1452 (GMT+8), at prime focus:-

1456 (GMT+8), with 2x barlows:-

1458 (GMT+8), with 2x barlows:-