Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [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 What am I looking at here?       #1563737 - 04/24/07 11:35 AM Attachment (43 downloads) Edit   Reply   Quote Quick Reply   While trying to find focus through a couple of focal reducers, I saw this defocus ring on my laptop. My question is, What are the little amoeba looking rings on the larger ring. They do not move or change size from frame to frame. Could they be dust motes somewhere in the light train? And if so, where might I look to clean them. And if not, what might they be? Richard -------------------- 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:       Chris_H Carpal Tunnel Reged: 11/24/03 Posts: 2858 Loc: Norway Re: What am I looking at here? [Re: Richard Scott]       #1563740 - 04/24/07 11:37 AM Edit   Reply   Quote Quick Reply   That would be dust -------------------- Chris "Big Papa Smurf" (254mm f/4.7 Sky-Watcher Newt) Custom Orion Optics 150mm f/8 reflektor "Planet Killer" (On its way!!!) SPC900 Canon Powershot A610 (CHDK modded) Canon 10D (modded) Canon EF 50mm f/1.8 II Canon EF 70-200mm f/4 USM L My Website Post Extras:       Andrew Welsh Carpal Tunnel Reged: 03/28/06 Posts: 2240 Loc: Rochester, NY Re: What am I looking at here? [Re: Chris_H]       #1563829 - 04/24/07 12:30 PM Edit   Reply   Quote Quick Reply   Dust motes for sure. Most likely on the sensor of your imaging device (webcam or whatever or CCD). A fact of life that only sensor cleaning (via bulb blowing or swabs) can rectify. Dust is unavoidable, unfortunately, even in the clean rooms where the sensor is manufactured. -------------------- LX200 8" classic, f/10, Meade eq. wedge, .63x FF/FR Canon 40D and 5D, unmodified Canon EF 300/2.8L IS, 400/5.6L, 135/2L, 50/1.8, 85/1.8, 35/2, 24-70/2.8L, and Peleng 8mm fisheye Orion Apex 102mm (4") Mak-Cass Pimped out with accessories and bling My DSLR Astrophotography Webpage and photo bucket with full equipment list Post Extras:       Dr Nick scholastic sledgehammer Reged: 01/27/06 Posts: 798 Loc: Glen Innes, NSW, Australia Re: What am I looking at here? [Re: Andrew Welsh]       #1565345 - 04/25/07 01:00 AM Edit   Reply   Quote Quick Reply   No doubt about it, thats dust for you... -------------------- 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: What am I looking at here? [Re: Dr Nick]       #1565362 - 04/25/07 01:13 AM Edit   Reply   Quote Quick Reply   The smaller the mote, the closer to your imager. Take a normal flat field ie in-focus and look at their size. They would be completely removed with flat frames so don't worry about them - (there are a lot though..check the optics too- have you had you OTA open?) -------------------- 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 01:22 AM) Post Extras:       TheNebulai Pooh-Bah Reged: 01/26/07 Posts: 1139 Loc: New Jersey Re: What am I looking at here? [Re: gavinm]       #1566497 - 04/25/07 03:46 PM Edit   Reply   Quote Quick Reply   Yeah, like everybody said already...the dreadful DUST! Sooner or later it was gonna happen -------------------- Equipment: Z10, Meade 8" LX90GPS, Galileo 120mm A bunch of EP's, Filters, and Barlows 10*50 Binocs Sony Cybershot,Philips SPC900NC,DSI Pro, DMK21AU04/ Astronomik LRGB Messier Count: 48 Post Extras:       John Carruthers Skiprat Reged: 02/02/07 Posts: 1701 Loc: Kent, UK Re: What am I looking at here? [Re: Richard Scott]       #1567764 - 04/26/07 05:47 AM Edit   Reply   Quote Quick Reply   If they won't blow off (bet they don't) a microfibre cloth will shift them. Any dust in the boundary layer on a chip will be stubborn. Just had to do both my webcams, crud everywhere :-( even though I keep them capped, or an old filter in place as a dustcap. -------------------- Jc ATM 10" F6.1, 1/25th wave spec (max wavefront error +/- 1/12.6 in zone 4 of 6, sodium light ) 6" F7 spec 127mm F9.4 Refractor 10 x 50 bin ETX80 (finder) Canon 20D and a curious mind Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 9 registered and 8 anonymous users are browsing this forum. 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