香港天文論壇

Tonight, with help of another helpful astrofarmer, I learnt calcuting the focal ratio of my jupiter pics taken on 2005/04/14. It was found at f/67!!! It is really something like 'Without big telescope, don't take big picture' (Astronomical version of 'without big head, don't wear big hat'. :oops: :o...

Yesterday I submitted the form lar (Ms Choi said I could submit cheque/cash later). Hopefully the application will be approved!
thanks
Elton

The equatorial mount is huge!!!
I mistakenly thought the DEC body is the RA body!

It looks completely tailor made.

I heard similar thing before in star camp, but that possibly only some misunderstood situation happened more than 20 ~ 30 years ago. I think now, it is not possible lar.

Subaru 寫:

XR250 寫:我都比人reject過

嚇, 乜會感嘅咩?

I see!!!
Thanks for this valuable info!!!

Subaru 寫:

Wah! 寫:對於不同seeing,光度或曝光時間, 個F值應該會有唔同.

我係講緊就算夠定夠光, 用f/40以上去oversample, detail都唔會有什麼改進.

Over pushed Jupiter, IO almost transit, with small earthquake (Final version) Image taken on 2005/04/14, 10pm (HKT) Nexstar 5 at alt-az mode Meade 2x barlow Steve Mogg extender 2 eyepiece projection adapter Toucam. Registax, PS processed 100%, 50%, short 50% animation. :D :D :D (Thanks for Wah! sugg...

Thanks Wah and Subaru. I am now decreasing both the contrast of the pics and gamma so the middle is not over.
I have heard there is a software measuring the pixels across the planet, what is that software? I don't know what is the focal ratio of last night setup lar.
thanks!
Elton ))

:D :D :D I think Last night I over pushed my 5 inches SCT, using 1 steve mogg extender, 1 eyepiece projection adapter, another eyepiece projection adapter for Toucam Jupiter planetary imaging. Look at the size of Jupiter in the stacked 640 x 480 frame in 100% (my god, I think I am way too greedy to ...

I am considering to join the "天文望遠鏡製作課程" this week, hope it is not too late, however I don't have cheaque book, a.) Is there any other payment method we can apply for the admission ga? b.) Besides, during the practical, can my girlfriend come to "tam ben" occasionally? She wants to see me grind mirr...

I want to join too, still hv the vacancy? Hopefully I am not too 超齡 lar.

Very interesting news!!!!!! Now the centre thickness is around 9.5 mm thick, still some margin to change the upper/lower position of the workpiece/mirror to increase focal length? Or it is too thin already? By the way, yesterday I read Mr. Wong's 'blue book' (self make astronomical telescope), it sa...

Thanks a lot for the comment.

Nexstar 5 (at alt-az mode) + 2x Meade barlow + Steve Mogg extension tube :-) http://www.hkastroforum.net/bbs/album_pic.php?pic_id=2744 http://www.hkastroforum.net/bbs/album_pic.php?pic_id=2745 http://www.hkastroforum.net/bbs/album_pic.php?pic_id=2746 http://www.hkastroforum.net/bbs/album_pic.php?pic...

All items sold.

Hi, SY Lok, hope adding the constellation lines would help. :-) b. rgds Elton http://www.astrofarm.net/dbphoto/loadimg.php?id=3638 Your photos are so nice. I haven't seen such beautiful sky in Hong Kong for a long time. Would you describe the sky in the first photo? I cannot recognise the stars. :sh...