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[Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> Beginning Imaging Previous   Index   Next   Threaded   Pages: 1 Richard Scott professor emeritus Reged: 07/25/06 Posts: 708 Loc: Tampa FL Question on dark frames       #1563742 - 04/24/07 11:38 AM Edit   Reply   Quote Quick Reply   Do any of you make and maintain a library of darks, 5 sec, 10 sec, 20 sec, etc and use them over and over, or do you burn and stack new ones each imaging session? -------------------- 11” Celestron XLT SCT Orion ED80 APO CG-5 GEM JMI NGF-CM Focuser Orion SSDSI Meade DSI Pro an assortment of 1.25” & 2" stuff all tucked inside the Blue Moon Observatory http://tinyurl.com/29b9wn Basically more scope than my abilities warrant "I know I can never look upon the stars without wondering why the whole world does not become astronomers." Thomas Wright Post Extras:       D_talley professor emeritus Reged: 07/07/05 Posts: 702 Loc: Richmond VA Re: Question on dark frames [Re: Richard Scott]       #1563798 - 04/24/07 12:14 PM Edit   Reply   Quote Quick Reply   I make new darks whenever I image so that I have the current temp/iso/camera time setting. Darks should have the same setting as the lights. Any masterdarks would be different than the current lights by temp in most cases. -------------------- Dwight TEC 140 APO Meade LX200 14 OTA Orion 12.5 DOB Celestron C8+ Celestron 102AZ Losmandy G11 Argo Navis Canon 10d Canon 350D Hyperstar ST-4 Guider STV Guider Post Extras:       Zyxlor Carpal Tunnel Reged: 09/10/05 Posts: 2120 Loc: St. Cloud, FL Re: Question on dark frames [Re: D_talley]       #1564038 - 04/24/07 02:15 PM Edit   Reply   Quote Quick Reply   I always shoot new darks at the end of my imaging sessions. But theoretically you can maintain a library based on exposure length and temperature. I shoot new ones in case the camera varies in it's hot spots from night to night. I don't know if this is a valid issue or not but I say better safe that sorry. I do it at the end of the session so that I don't waste valuable imaging time. -------------------- Zyxlor ++++++++++++++++++++++++++++++++++++++++++++ Tak TSA-102S Tak EM-200 Temma 2 Meade 10" LX200 OTA now removed from forks- OTA is now rigged to go onto Tak mount. Celestron EB80 Piggy backed on TSA102 or 10" SCT which ever is in use! Meade DSI Pro II (a great guiding camera!) Philips Toucam Philips 900NC SBIG STL-11000M Astrodon LRGBH 50mm Post Extras:       thelittleman Vendor (Peter's Actions) Reged: 05/21/05 Posts: 4077 Loc: Hampshire, UK Re: Question on dark frames [Re: Zyxlor]       #1564134 - 04/24/07 03:07 PM Edit   Reply   Quote Quick Reply   I am trying to start building up a library. With a cooled CCD camera is is very easy - you always cool your imager to the same temperature so you only ever need one dark (perhaps updated every year or so). As a DSLR man, it is more complicated. I have a digital thermometer which I take out every night. I am just beginning to put a small library together with ISO speed, exposure length and temperature. ATM I leave my camera and laptop in the conservatory where the temperature is similar to outside, and leave it clicking away all night which seems to work pretty well. It really boils down to personal preference! To be honest they are a bit of a pain to take and very time consuming! -------------------- Clear Skies, Peter Photoshop Tutorials and Actions! New actions now added Preprocessing in Iris Tutorial http://peter-morris.magix.net/ Post Extras:       nik hodges professor emeritus Reged: 04/20/07 Posts: 633 Loc: UK Re: Question on dark frames [Re: thelittleman]       #1564151 - 04/24/07 03:17 PM Edit   Reply   Quote Quick Reply   i was wondering about this to, ive been making darks each sesison so far (only had 2) but im not entirely sure it is neccessary -) -------------------- Flurostar 110 [TMB] with TAK TOA/FS 0.75 reducer Megrez 80mm triplet apo & mkIII FF "LX200R" (8") with AP CCDT67 reducer & moonlight focuser StarlightXpress SXVF-H16 camera/trutek filter wheel DSI Pro II Maxim DL/Maxpoint + adobe PS3extended On AP900 notification list Post Extras:       s58y Post Laureate Reged: 12/12/04 Posts: 4850 Loc: Eastern NY Re: Question on dark frames [Re: nik hodges]       #1565002 - 04/24/07 09:36 PM Edit   Reply   Quote Quick Reply   Recently, I've been DSLR shooting only at ISO800 and mainly for 1 minute, 4 minutes and 10 minutes. I've been building up a library of darks at various temperatures (20F, 36F, 24F, etc.) for these exposure times. Some of these are taken in the freezer or refrigerator. -------------------- Hutech 30D, SBIG ST-402 autoguider SV80S, SV66 guidescope AP900, G-11, Barndoor tracker http://www.pbase.com/s58y Post Extras:       ChazK Pooh-Bah Reged: 11/23/05 Posts: 1453 Loc: Melbourne, Florida Re: Question on dark frames [Re: s58y]       #1565023 - 04/24/07 09:48 PM Edit   Reply   Quote Quick Reply   I agree with the new darks every session.. Just to be sure there in no new noise issue that night either temp changes, amp glow changes, etc -------------------- Tak TOA 130mm/NJP Temma2 Tak FS 60CB Canon 40D (unmodded) Astronomik CLS Canon EF 28-135mm f/3.5-5.6 www.digitalunatic.com Post Extras:       Dr Nick scholastic sledgehammer Reged: 01/27/06 Posts: 798 Loc: Glen Innes, NSW, Australia Re: Question on dark frames [Re: ChazK]       #1565313 - 04/25/07 12:37 AM Edit   Reply   Quote Quick Reply   I just let autostar keep building them up, and if it says that I dont have any for that temperature or exposure time, I shoot more, or if they aren't working well, I will also shoot more. -------------------- Clear Skies, Nick http://www.NicksAstronomy.com Sky Watcher 8" f/5 Newtonian(which I got when I was 10yrs old and 5yrs later I'm still adding to) w/JMI motofocus/standard, axis guider. ToUcam Pro w/Phillips vlounge/registax/and Virtual Dub, DSI Pro II w/envisage/photoshop cs2/, Post Extras:       gavinm professor emeritus Reged: 08/26/05 Posts: 559 Loc: Auckland New Zealand Re: Question on dark frames [Re: Dr Nick]       #1565353 - 04/25/07 01:06 AM Edit   Reply   Quote Quick Reply   For a low-noise master dark, you need hours of exposure time (at each temperature). Easy for a TEC CCD, possible for a DSLR but hard work I would imagine. Darks are easy to take in reality. Also a master dark is not as 'good' as same exposure darks and really need to be updated every month or so. Oh and you generally scale a master dark to the required exposure time.. thats why you have it. -------------------- Gavin Mt Albert Grammar School Observatory Auckland, New Zealand http://www.mags.school.nz/astronomy/index.html 12" LX200R w/ UHTC SBIG ST7-XME + CFW10 Skywatcher Equinox ED80 Pro (ADM dovetail) + other stuff Edited by gavinm (04/25/07 01:07 AM) Post Extras:       Dragon Man sage Reged: 03/07/06 Posts: 229 Loc: Snake Valley, Australia Re: Question on dark frames [Re: gavinm]       #1565495 - 04/25/07 05:26 AM Edit   Reply   Quote Quick Reply   I make a dark for each object at the end of the imaging run of each particular object. That way I am sure it matches temp, time etc. -------------------- IMAGE EDITING AND COMMENT APPROVED Ken - 12" Dob on a Restored EQ | 8" EQ Reflector | EQ6 & synscan | ED 80 | Modded 840 Toucam Pro II | 20x80 Triplet Binoculars | Snake Valley Astronomical Association and my own site Australian Astronomy Who's the Idiot that invented the Light Bulb! Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 9 registered and 7 anonymous users are browsing this forum. 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