robulack
member
Reged: 10/11/09
Posts: 11
Loc: Vancouver, BC
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I've been taking pictures for the last two years and getting frustrated with my results. I have an 8" Skywatcher Newtonian on an EQ5 mount. I use a Nikon D50 mounted directly to the scope. I fight with polar alignment and focus. The pictures I get I try to stack but they don't seem to get any better than the one 30 sec shot and then I try to figure out what to do next. Anyone got a short list of sequences to go through to get some of those great pictures I see in these forums?
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s58y
Postmaster
Reged: 12/12/04
Posts: 5507
Loc: Eastern NY
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Try a smaller scope, with bigger/easier targets. Perhaps try a small APO refractor, or a telephoto lens.
Start autoguiding, and take longer subexposures. If you have bad light pollution, either go to a dark site, or use narrowband filters to cut through light pollution.
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Hutech 30D, SBIG ST-402 autoguider
SV80S, TV102iis
Old camera lenses: 800mm f/5.6, 180mm f/3.4
AP900, Barndoor tracker
http://www.pbase.com/s58y
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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You are shooting in RAW mode without any camera noise reduction?
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Dwight
SBIG ST2000xm
TEC 140 APO #74
Meade LX200 14 OTA
Orion 12.5 DOB
Celestron C8+
Celestron 102AZ
Losmandy G11 Gemini
Argo Navis
Canon 350D self mod
Hyperstar
ST-4 Guider
STV Guider
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Patrick
Postmaster
Reged: 05/16/03
Posts: 7808
Loc: Franklin, Ohio
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Hi robulak and welcome to CN!
Quote:
I fight with polar alignment and focus.
Welcome to the club!  The best way to get a good polar alignment is to drift align. If you do a google search on drift aligning you will find a large number of sites that explain the process.
Regarding focus, there are a couple of ways to go. First, do not bother trying to get focus through your camera's back of camera LCD. You will want to hook the camera up to the computer or take images and download them to your computer to verify focus.
There are a couple of good aids available to help get to good focus. The first one is the Bahtinov masks (do a search) which will give you a specific diffraction pattern as the scope approaches focus, and when in focus. Another aid that I use most of the time that's really easy to use and very accurate is the Stiletto IV knife edge focuser. I can focus my scope in 15-30 seconds with that device and did I mention it's very accurate?
Regarding the rest of your setup... as note above, it's not going to be the most user friendly imaging setup. You have two things going against you. First the mount is overloaded with the 8" Newt and secondly, the mount's accuracy in terms of periodic error is not good enough to handle a 1000mm focal length scope. It sounds like you're imaging without guiding and you will never be successful at that focal length without it.
I would suggest that you replace or supplement your current setup with a small refractor on at least a CG5-GT mount or better yet, a Sirius or Atlas mount. You might even be able to image with the 8" Newt on an Atlas mount.
Clear skies,
Patrick
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10" f/6 Truss Tube Newtonian
Celestron C6S-GT SCT
AT66ED Refractor
Oberwerk Ultra 15x70 Binocular
475B Geared Tripod & 501HDV Head
Celestron Regal 8x42 Binocular
Canon XSi; Meade DSI;SPC900-NC
Vixen GP2 Photo Guider Mount
My Astronomy Pages
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WarrenS
scholastic sledgehammer
Reged: 03/04/08
Posts: 895
Loc: Orange County New York
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What are you doing in the way of post processing? Stacked images out of Deep Sky Stacker which I use always show less detail. It's the stretching using curves and levels afterward that bring out image. 30 second sub exposures are short for many but not all deep sky objects, you'll need to get at least an hour's worth though. The best thing I think you should do is get this CD book from Jerry Lodriguss, who posts here in the DSLR forum. http://www.astropix.com/BGDA/BGDA.HTM
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Warren
Astro-Tech 127EDT
Celestron Onyx 80ED
Astro-Tech Field Flattener
C8 (circa 1983 Orange Tube)
Atlas EQ-G, Orion SSAG
Canon 135mm F2.8
Canon 40D, Astronomik CLS clip filter
Leica, Minolta binos
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robulack
member
Reged: 10/11/09
Posts: 11
Loc: Vancouver, BC
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After I stack, I do nothing. That was the question, what to do next. Thanks for the book reference.
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robulack
member
Reged: 10/11/09
Posts: 11
Loc: Vancouver, BC
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Have been considering another scope. My site is pretty dark.
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robulack
member
Reged: 10/11/09
Posts: 11
Loc: Vancouver, BC
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That's correct.
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Alex McConahay
super member
Reged: 08/11/08
Posts: 130
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The short answer is: "No." There is no single short list of sequence. There are several books (or books on CD). Start with Jerry Lodriguss's efforts.
I can tell you, though, that getting results can take time, effort, patience, and diligence. Me being a lazy and imprecise person, I will never be a good astroimager. I take too many shortcuts.
Your frustrating results are hard to diagnose without seeing the results, and talking about your processing.
Is the problem that the stars are not round? Are they round, but too large?
After you stack, are your stars all registered, or are you getting double (multiple) exposures?
Or are you frustrated because after stacking they are still too dark? What have you done to stretch the curve?
There are so many things to check, that it is hard to do in a Forum like this.
Just hang in there and go slowly, one thing at a time.
Alex
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robulack
member
Reged: 10/11/09
Posts: 11
Loc: Vancouver, BC
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The alignment and focusing have been areas that I'm slowly resolving and the mask is being reviewed right now. Also looking at the EQ6 for my setup as well as putting in a pier since I have my own observatory.
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robulack
member
Reged: 10/11/09
Posts: 11
Loc: Vancouver, BC
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Thanks Patrick will look into drift alignment. Wasn't aware of it before joining this group.
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dwitek
super member
Reged: 07/03/08
Posts: 157
Loc: White Lake, Michigan
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Quote:
After I stack, I do nothing. That was the question, what to do next. Thanks for the book reference.
After stacking in DSS the resulting images will be almost non-existent without post processing. The real work is using Photoshop or Pixinsight to bring out the data that's hidden near the dark end of the brightness spectrum. Start with simple histogram changes and using Curves or Levels depending on what software you're using. Generally, I spend as much time working with an image as I did taking the images in the first place!
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10" LX200 EMC Classic
Milburn wedge
Peterson Eye-Opener system
2" Dielectric Diagonal
JMI NGF Crayford focuser
Meade DSI Pro III
Meade DSI Pro I as autoguider
Piggybacked Stellarvue SV80ED
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AlanT
sage
Reged: 08/20/07
Posts: 488
Loc: 122º36' W, 47º37' N, WA USA
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What Dwitek said about what you get using DSS is what I see too. I put up a very basic tutorial on what to do next on this web page.
Maybe it will help.
al
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al
Meade 80mm APO
Celestron 6" SCT
CGE, GM-8, & CG-5 GT
ST-2000xcm, DSI Pro II, DSI Pro
( www.alberts-astro.com/astro )
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