Falak-Online Komuniti

saya mula dgn tips

#1. periksa dan pasti sensor DSLR anda bersih.

Setelah bertukus lumus satu malam ambil lights bila nak proses, alamak terdapat no "3" di gambar


(http://www.pbase.com/aziz/image/91170376.jpg)

caranya

1. set flash to off, set manual fokus and fokus ke rumah jiran. set kamera ke Av, ISO 100 aperture to f16 atau f22. tangkap gambar clear blue sky or evenly light overcast.

2. kalau hujan then all you need is some uniform surface, like a white painted wall or ceiling or something or a sheet of paper is fine too.Turn off the flash, turn off auto-focus, stop the lens down to f/22. Press the shutter button, and sort of "sway" the camera around to blur out any detail in the wall's surface.


Kedua2 cara you'll end up with a nice picture of the dust on the sensor.

Baca arahan mencuci dekat kamera manual . for Nikon you can send to Nikon Centre for free cleaning. Canon charge for sensor cleaning unless you are a  CPS member.

cheers

My contribution

#2 - Tutup viewfinder semasa ambil lights, darks, flats, dark flats

Dengan menutup viewfinder kita dapat mengelakkan stray light daripada memasuki kamera dan mengenai sensor.  Kita hanya mahu cahaya dari langit sahaja utk mengenai sensor, bukan dari sumber2 lain.  Masa ambil gambar biasa no problem pasal mata kita akan menutupi viewfinder dan stray light tidak akan masuk tapi astrophotography biasanya kita tidak melihat melalui viewfinder.  Kalau Canon EOS kita boleh guna viewfinder blocker yang diberikan sekali bersama strap.

Hi all,

1 cent from me:

About Dark Frames, Dark frames must be the same temperature and ISO setting as the light frames otherwise the "footprint" won't match. Don't fall into the mistaken belief that you can use the same master dark all year on different images. The reason for this is that as the camera ages, the chip and electronics changes ever so slightly and soon you'll be seeing gamma ray hits on your images. To get good quality images, take about ten darks either before or after taking your series of light frames and then combine them into a "Master Dark" Dark frames can easily be done by simply covering the lens with the dust cover while slewing to the next object..You can take DSLR darks any time with the camera lens cap on in the obs or in the office as long as the temperature is similar, minimising cosmic ray hits. DSLR darks tend to be more consistent and predictable due to the processing algorithms in the DSLR.

P/S: Take some attention on the words that I highlighted.

Regards,

Tommy

After taking their RAW images  the light, darks, flats and bias are first process in DSS, MaxIn, n other and the massaged and polished in Photoshop for final presentation.

All these are explained in Photoshop for Astrophotographers by Jerry Lodrigus. Photoshop is not for the meek; it has a steep learning curve :-o

I also come across a few plug-in/actions that most astrophotographers uses with Photoshop

1. Noise Ninja or Neat Image for noise reduction

2. RC Gradient Exterminator

3. Noels action for that final look




Of course one must have a great image to start with as can be seen in this example of the M42  and yet he is still not satisfied :?

http://www.astro.artistsloft.com/thesword1800.html (http://www.astro.artistsloft.com/thesword1800.html)

according to his email :the outer areas were either 360 or 480 seconds at f5.9, the center was a stack of 1, 30, 60, and 360 second exposure sets, combined according to Lodriguss with layer masking..  I use a Hap Griffin 350d...  I am finding the fringes too noisy at 480 so plan to shoot another series all around this image at 600s if the weather ever clears...  makes a very big file by the way

Anybody knows of others that is  useful to help in the evangelical quest for that perfect National Geographic image.

cheers

Proper polar alignment as I understand it is to avoid field rotation during imaging which produce oblong stars.

Guiding is to track on one star known as the guide star  whether manually (by staring in the eyepiece at a guide star and manually adjusting the movement of the  scope to keep the guide star in a fixed position)or on auto (same but using electonic eye and dedicated electronics or software with a computer) is to correct for mechanical imperfections in the mount or alignment error or both which also produce oblong stars.

So the more expensive your mount the less mechanical errors you face. So you buy the most expensive astrophotography mount you can afford.

But..but that leaves with polar alignment. This involves skill and experience. Is there any quick but effective method of doing polar alignment.

By the time I finished my drift alignment it is time to pack up :cry:

cheers

I found an interesting website for polar alignment. Flash required.

http://www.petesastrophotography.com/index.html?mainframe=http://www.petesastrophotography.com/polaralignment.html (http://www.petesastrophotography.com/index.html?mainframe=http://www.petesastrophotography.com/polaralignment.html)

ClownFish also has a lot of infomation on astronomy and a Guiding Simulator too.


another gif animation is at

http://www.hkastroforum.net/bbs/viewtopic.php?t=969#7615  (http://www.hkastroforum.net/bbs/viewtopic.php?t=969#7615)



cheers

another site for polar alignment

http://www.andysshotglass.com/DriftAlignment.html (http://www.andysshotglass.com/DriftAlignment.html)

cheers

syabas kepada UIAM Kelab Astronomi kerana memperkenalkan topic space defence/shield dalam ushaha mempromosi astronomi. Sunggoh relevan sebagai satu contoh aplikasi bidang astronomi. :mrgreen:

cerapan washout. awan tebal sahingga bulan tak nampak. Tapi jam 1 pagi awan mulai reda; bulan dan jupiter timbul dan dapat dilihat menerusi bazzoka tokei. :-D

beberapa soalan timbul mengenai bermula astrophotographi selepas dibeli DSLR.

mula kan dengan click  disini   (http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM)

dan  disini  (http://www.covingtoninnovations.com/dslr/EOS300Dastro.html)


DSLR boleh diguna juga waktu siang hari. Dicadangkan satu aktivity outdoor pada siang hari tapi kena ambil dengan RAW file format dan selepas itu belajar process gambar. ini dinamakan "workflow". saya nampak banyak "model" dari UIAM dan UPSI  :-D

dari laman web contoh  disini  (http://www.dcviews.com/tutors.htm)  dalam  "tutorials "

Aktiviti ini telah dijalankan oleh En DinPerak di Teluk Batek awal tahun ini. mungkin falak online boleh buat repeat.


workflow natural daylight fotografi sama tapi  workflow astrofotografi memerlukan beberapa step tambahan :-o



cheers

Bazoka tokei begitu berbakti pada malam tadi.. hehe.. telah dapat di-internationalize-kan .. huhu  :wink:


ya betul... passing-passing  la  foto  'object of interest' malam tadi.. tak leh tidur malam..semalam...  :-D


InsyaAllah akan dibuat jugak. Ramai member-member baru  dan yg sempat ke Teluk Batek, nak belajar jugak.

Yups..betul la tu en.shah..

saya sokong sgt2lah kalu falak-online nk wat lg bengkel bg beginner dlm astrofotografi ni..insyaAllah sy n kwn2 yg berminat akan join jika diberi ksempatan & masa.. :-)

It is my belief that for astrophotography there is no need to buy a telescope. Camera lenses will do just fine.

Yes, you can use practically any of your existing lenses to do satisfying Deep Sky (beyond the Solar System) astrophotography, those wonderous nebulae and galaxies. Just depends on your choice of framing appropriate to the focal length.

My internet sifu has reorganised his website. He uses 14mm to an equivalent of 4000mm on a 1.6X crop body.

HIs examples can be found here  (http://www.pbase.com/samirkharusi/focal_lengths)

Another sifu who uses camera lenses is click here  (http://www.clarkvision.com/galleries/gallery.astrophoto-1/index.html)

I will therefore use my WO FLT110 and the C8 as a guiding scope and for drift alignment :-D

and for observing.

cheers

How much ek nak remove filter yang block H-alpha dalam camera tu? kasi ganti dgn UHC atau Baader filter...

pastu ada tutorial untuk cabut & pasang baru sendiri punyer ke?

Wah dengan ISO 6400 with the D3  there is no need for 60sec subs. at f4 :evil:

Untuk cabut dan pasang sendiri sila  click  here (http://strgazr27.zenfolio.com/p71444939) contoh 40D

When I saw what's involved  I chicken out and have Hutech modified mine :-D

 modify your camera with

either Hap (http://www.hapg.org/camera%20mods.htm)

or Hutech (http://www.sciencecenter.net/hutech/canon/index.htm)

but I believe some locals are doing it too. Ask CK Lim or William.

cheers

I hand over to a local camera shop to do the removal and install of new filter for astrophotography.
I got source in HK do sell modified Canon EOS DSLR camera. Not recommend to do the modification on Nikon as so far no compatible astronomical filter designed for Nikon camera.

Hohohohoho! nampaknya mmg cari penyakit juga kalau nak tukar sendiri ni.

Tukar filter ni kira void warrantty kan?????