自制家用天文台 --- MANDII ( HONG KONG )

[MANDII]

Cloudy Nights

nytecam 12/23/10 07:20 AM from LONDON UK

Many thanks Mandii for the detailed photos and explanation - well done

Being pedantic, as an architect, I'd abreviate it as a concealed upstand edge [on the inner 'dome'] and a downstand drip on the outer over-riding 'dome' to stop wind-driven rainwater penetration






MANDII : 12/23/10 10:00 PM
Rain water was the first consideration .
2nd master consideration was heat insulation from the SUN .

To me , heat insulation is a key point , why ?
Because this factor determined how much use the observatory can be . The more the observatory can be used in various ways , the more valuable a observatory is .

As you can read my first post the objective of this project written on 3rd of september ,2009 ( beginning stage).
The observatory is not only aims in Night Astro-Hunting , but also used in daytime working(making plastic models) , reading books , taking a rest , etc .. And now in real usage from the past 1 year time , it's mainly use in playing the on-line games and do some Plant observation and imaging under telescope imaging system in daytime afternoon . Or sleeping inside . It did expand at least 50% of the observatory usage , by making it cool inside in daytime .


Two ways to achieve the goal of coolness inside the observatory .
1. I choosed to use the red bricks and cement as the structure of the body .Around total 8cm thickness of the wall and ceiling , Plus the high quality(600RMB)heat insulating coating paint that was bought far away from North West China ,it can reduce the room temp. to about or more than 20 degree celcious below the outside temp. in hot summer . About this pianting ( green bucket in pic.0 of prv.post),In last summer , outside temp. was about 35degree , when you put your hand over the platform ground , it's very hot ! It could be over 50degree on the ground surface . However , when you put your hand over the outter wall surface of the observatory , it was just warm feeling ! I guess less than 30 degree . And internal wall surface was much lower than external wall surface , feeling a bit warm indeed !!! And of couse , the room is very cool . That was very amazing at that time as I experienced !


2. The door was designed to be built in South side .
This is simple , but very useful !
When the dome is opened at Northern side, and the door is opened just a little in southern side ,natural cool wind is drawn automatically into the room , feeling very comfortable .


3. By using the bricks and cement with such thickness of 8cm , it is a good Sound insulator as well .
You will feel that it looks like a Cave on the platform indeed ! The inside is kept highly silent and cool when you close the door and dome , looks like a cave . When you speaking or listenning to music from computer , you will hear the echo sometimes ,very sharp and strong base music !


Merry Christmax Everybody on every astronomy corner of the world !!

OBSERVATORY made by own -- MANDII (HONG KONG)
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Board/Observatory/Number/4261234/page/0/view/collapsed/sb/5/o/all/fpart/1




Best Regards
MANDII
2010/12/24

[MANDII]

2010年12月26日一晚(9:00-12:00)用人肉GOTO拍的4个深空

[MANDII]

moved .

[MANDII]

本人过往热衷于股票买卖,喜欢刀仔锯大树,大起大跌，最为刺激。
同理，玩天文也不例外，多劳多得，多发几张照片便多得文章的点激数。

这个是过去半年里于各个地方的天文论坛,文章发表的点激数统计。
一共14篇主要文章作记录,包括以"自制家用天文台 --- MANDII "的文章为首,
同时更新4(还在添加中)个地方具有代表性的天文论坛,包括香港,美国,台湾和中国。
每月4个论坛总的点激数“增长”有升有跌，本人称之为‘恒心指数“ ， 粤语‘心’和‘生’是同音字，
与香港股票市场的”恒生指数“类同，哈哈！
此指数，记录于香港论坛的"自制家用天文台 --- MANDII "的文章里，每月15日查数更新。

2010年度12月份本月（图恒心5），恒心指数首次突破2万点 ！！升6000多点。
谢谢大家支持！哈哈！



并祝各位新年快乐,身体健康。

MANDII
2010/12/31

[MANDII]

moved .

[MANDII]

< US ASTRONOMY >


Uncle Peter : Today, 03:23 AM from Toronto, Ontario
Mandii,

That's one great observatory that you've built! Just from one look, you can tell that that thing is solid. It's great that you posted your progress on it here, as well as pictures; they are very inspiring for other people.

You have some really great moon photos, too. I am trying to get into astro-photography, and have started on the moon, identifying a few of it's seas and craters along the way.

One question though, does your observatory help to decrease light pollution?

I can't wait to see more of your photos.

Clear Skies,

Uncle Peter




MANDII : Today, 09:10 AM
Thanks Uncle Peter‘s comment ,

You mean how the observatory can be hided from some of the outside light source ?
Or how the light pollution come from the sky , can be reduced it's impact in taking the images ?

For the first question , the dome halves can sheild away from much of the outside light sources already .
At least halfly ( 180 degree) light is avoided . Sometimes I even open the dome much less , with a little hole only, that can let me still enough to observe the object . Normally I kept very dark inside the dome( no lamp , PC monitor turns off , use red light star chat etc...) , during observation time .

If you are asking the 2nd question , I think you know that most people would choose to use some kind of imaging filters , to get rid of light pollution . However , for the moment , I didn't use filter yet .

Hope this answer are helpful . . .

[MANDII]

<<中国牧夫>>

wweiboo: 2011-1-17 18:41
这也太厉害了吧，太强了


MANDII : 2011-1-18 09:53
------------
谢谢
------------

[MANDII]

< US ASTRONOMY >

Uncle Peter : Yesterday, 04:46 AM from Toronto, Ontario

Yeah it was the first question I meant. Thanks for answering it Mandii.

[MANDII]

moved .

[MANDII]

去年6月8日买回来的ORION 6" F5 牛反,当时考虑到原来那部牛反要拍再多些深空，计划是大半年后使用,
今天突然想换,便做了个连接部位,把它安装好，正式启用。
这是我的第二部天文望远镜,很可能会是最后一部,我希望会一直够我用下去。



MANDII
年初三（2011）

[MANDII]

US ASTRONOMY

samgray1 : Yesterday, 12:03 AM from San Diego, Calif., USA
It looks good Mandii.


Uncle Peter Yesterday, 01:34 AM from Toronto, Ontario
Nice set-up Mandii and great shot of M50.

What kind of mount are you using for your 6" Orion? It looks like an EQ mount, but I'm not sure which one it is.



MANDII : Today, 09:47 AM
Yes, it's the "智通"EQ3 made in China ,with one motor , no goto and guiding .
A new one is selling several hundreds Hong Kong Dollars in the market .
It carry up around 10KG things on a normal star tracking , I think .
I had used it nearly 1 year with my 4" Newtonian without complaint on it's perfomance in such good price .And now , it's going on the tough hunting task with this newly installed 6" newtonian .
So far so good , within my estimation when I decided to bring it home last year .



中国牧夫

louww :2011-2-5 20:30
用那个双筒镜的时候，空间是不是有点小啊？!

MANDII : 2011-2-6 00:15
双筒镜最近才重新开始用,偶尔看看，还行吧空间,用单筒拍摄时把双筒放一边，坐在里面看双筒挺舒适的感觉。

[MANDII]

US ASTRONOMY



sxinias : Today, 12:23 PM from Sxinias Marathon Greece
Mandii,

Congratulations on getting your 6 inch telescope in operation. You are doing some good work without sophisicated equipment. Have you had the opportunity to accurately polar align your mount?

Joe



MANDII : Today, 02:56 PM

Dear JOE ,

The day of 5th Feb , I setup this scope .
On the same night , I did polar alighment by Drifting method , and took the picture of M50 & NGC3242 .
Polar alighment is always important . In my situation , it helps me to find the object efficiently ,accuratly ,and helps to track the object during the imaging process . To explain this two points indepth , it can be too much to say .
For this time , I want to say something about how I do the polar aligment , find the object , and track the object into pictures . It's my first time to explain this in this forunm , in English .

I did the drifting not by naked eye with eyepieces .It's done on a computer screen by inserting the camera(DSI-I) . The EQ3 mount is turned the polar at the same time when I look at the star moving-discrepancy from the screen . The more exposure time taken in a single flame , the more discrepancy( star tails) we can see from the screen . And then adjust(polar align ) the mount to reduce the discrepancy .

2ndly , if the mount is not aligned well , I can't find the DSO objects properly .
Actually , I am not free-finding the objects , like the star-hooking inside the eyepiece .
Becasue star-hooking is difficlut in my case , there is not much stars in the View finder. The FOV in an eyepiece(25mm eyepiece ) is so small( less than 1 degree) , and the star positions is always rotated to some degrees in a Newtonian scope , it's not fully inverted as the normal refractors do . So you cannot easily recognise those stars in a mean time , when you are looking at the the star-chat at the same timming. In summary speaking , It's very hard to find the object .
Indeed , I was usually using the numeric calibration ( RA and DEC scales ) on the mount . I turns the RA axis according to the time angle of an object ,meaning the RA value the object is located at the time it is observed . Let say this moment the object is located at time-angle 22h10m , the next hour it will move to position 23h10m . The time angle is very looks like to the RA value of an object , but it's changing with time and RA is fixed . After the mount's RA axis is rotated well , I turns the DEC axis to the DEC value of that object , this is traight forward because the DEC of an object is always fixed whenever any time is concerned .
THE ABOVE METHOD TO FIND AN OBJECT , I PERSONALLY CALLED THE " MANUAL GOTO" , it's similar to electronic GOTO , but using your own hand . If the mount is not aligned well, I can't see the objects within the FOV . This time , I can see the M50 and NGC3242 within the eyepiece FOV , by just one time turning of the RA and DEC aixs . It's located not really at centre , but within the area of the FOV .



3rdly , the polar alignment is aimed to star tracking in imaging .
My tracking this time was 1 minute single exposure , for total 10-20 minutes .



BR
MANDII

[MANDII]

中国牧夫

三味_jim : 2011-2-7 15:25
資金啊。。。只能等將來了


MANDII : 2011-2-7 16:17
年初三当晚拍的,赶新年新镜开光日 !
谢谢大家观看,哈!

[MANDII]

US ASTRONOMY


dmbryan : Yesterday, 11:56 PM from b'ham alabama
Looks like a nice setup there. Congratulations.


Lenbo : Today, 01:05 AM from Cochranville Pa.
Looking good MANDII. Great use of your available resources. You've come a long way.


PBalu : Today, 01:14 AM from Bloomington, Indiana
Nice work Mandii. I like your observatory too.

[MANDII]

中国牧夫

sunyuanzhen : 2011-2-10 11:59

村屋就是好啊。以前在大埔住的时候那个天，随便一看就是一大堆星星啊~ 羡慕一下楼主的天文台~



MANDII : 2011-2-10 17:07
原来系自己友 , 多谢 !
新年快乐!



US ASTRONOMY

Uncle Peter : Yesterday, 10:42 PM from Toronto, Ontario
Ah I see, thanks Mandii!