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Title: M8 & M20 Post by: universe24 on May 10, 2008, 05:04:20 PM Hi all,
After the instant test shot of M8 & M20 few days ago, the sky clear again last two night. For this time, my target is to expose a single frame as longer time as possible, based on a concept of longer exposure time, better image quality. Below is the final processed image. Mod350D + light pollution filter Intane 80ED, f/7 refractor RAW mode ISO200 21 x 180s = 63 minutes Image calibrated with bias/offset, dark & flat-field Note: This is taken just 2-3km from KL city center. Very close (~100m) from MRR2 highway in Cheras area. (http://www.hkastroforum.net/files/m8_flat_a_173.jpg) Title: Re: M8 & M20 Post by: mymoon on May 11, 2008, 12:20:58 AM Wow sifu makes it look so easy. at ISO 200 some more. Congratulations. i know how difficult it is to get one but two and aimed smack in the center i salute.
cheers Title: Re: M8 & M20 Post by: universe24 on May 11, 2008, 12:28:01 PM When we do astrophotography, although the weather is the most unpredicted factor, but we still have to make sure everything in well condition, then only we shot.
Well condition mean: mount aligned, well focus adjusted, camera setting checked & etc.... All this setting need time to achieve. But once you get all the thing done and the sky still clear, no excuses on cannot get astrophotos. Title: Re: M8 & M20 Post by: mymoon on May 12, 2008, 11:05:43 AM When we do astrophotography, although the weather is the most unpredicted factor, but we still have to make sure everything in well condition, then only we shot. Well condition mean: mount aligned, well focus adjusted, camera setting checked & etc.... All this setting need time to achieve. But once you get all the thing done and the sky still clear, no excuses on cannot get astrophotos. Thanks Sifu for the reminder. Yes you have to go throught a check list ala pilot's preflight check. Remembering to keep your cool even when you see clouds moving in is easier said than done. Nothing beats experience to remember the whole lot of items one has to check for. So practise and practise and practise until the drill becomes part of you. For those interested on the cookbook for EQ mount astrophotography you can go here http://www.saratogaskies.com/articles/cookbook/index.html (http://www.saratogaskies.com/articles/cookbook/index.html) For Fork Mounts goto http://astro.welsh-house.net/tutorial.html (http://astro.welsh-house.net/tutorial.html) but nothing like the 3Ps: P for practise :-D cheers Title: Re: M8 & M20 Post by: redzuan on May 12, 2008, 04:52:18 PM minta maaf. saya baru kat sini. Nak tanya light polution filter tu guna mcm mana? apa ke bendenye tu? pakai mcm mana?
last skali, steps in processing buat apa? Title: Re: M8 & M20 Post by: universe24 on May 12, 2008, 06:29:24 PM Hi redzuan,
Light pollution filter itu seperti namanya adalah diguna untuk mengurangkan light pollution. Cahaya dari bangunan dan lampu jalanraya yang dipancarkan pada waktu malam akan dipantulkan oleh atmosfera balik ke atas bumi. Dari segi gelombang cahaya boleh nampak, cahaya yang dipantul pada panjang gelombang tertentu sahaja. Light pollution direka untuk mengurangkan light pollution dari panjang gelombang tertentu dan memberikan laluan panjang gelombang yang dipancarkan dari bintang-bintang terutamanya nebula yang sentiasa memancarkan panjang gelombang dalam OIII, SII dan Ha. Light pollution filter bentuknya seperti filter-filter warna biasa. Biasanya dipasang di belakang teleskop. Steps in processing lebih tumpu kepada imej kaliblasi (image calibration). Ini adalah untuk membuang signal-signal yang tidak diingini dan tidak relevant yang muncul dalam imej yang kita ambil. Kalau tidak melakukan processing, imej keluar mungkin tidak licin dan bersih seperti televisyen tidak dilaras dalam channel yang betul. Title: Re: M8 & M20 Post by: MUZZAMIR on May 12, 2008, 06:30:50 PM Jom pi n9.. Ramai Pakar astrofoto berkampung disana nanti.. boleh tanya macam2 soalan... :-D
-muzzamir- |