cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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I know, I know, my standards have become very high indeed, but after imaging for several hours last night and then several hours of stacking and processing I was left with garbage.
I don't know why my flats didn't seem to take, after what I thought was careful framing it turned out to be not what I wanted and focus turned out to be a bit soft. In short a whole night wasted.
I'm about ready to throw in the towel and get some binoviewers and leave this imaging stuff to people who know what they are doing!
After 2 or 3 hours of effort I got this:
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
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www.aznightsky.com
Scottsdale, AZ
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diabolic
super member
Reged: 10/19/06
Posts: 112
Loc: Austin, TX
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I have had several nights like that. I like to think it's just another step on the learning curve ladder, but it's especially frustrating when you get nothing and didn't learn anything either.
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Will
WO Megrez 110 ED • WO ZenithStar 80 II ED • Celestron 9.25" Carbon Fiber SCT • Orion XT10i • Meade ETX-125AT
Canon 40D • Meade DSI-Pro II • SPC900NC
Celestron CGE
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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What were your subs exposure times? How many did you take? Did you take your flats after the image run to remove the dusk specks? Did you take darks to get rid of the amp glow on the right?
I like the photo myself. Just a little more work. (It never ends)
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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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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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Here are the stats:
Scope: Astro-Physics 160EDF at f7.5
Mount: Orion Atlas EQ-G with EQMOD
Guiding: Orion 80mm f/11.4 Guidescope with Meade DSI and PHD as autoguider. Auto guiding exposures .5 seconds.
Camera: Canon 350 EOS XT modified.
Lights: 30 exposures of 2 minutes
Darks: 5 exposures of 2 minutes after the lights.
Flats: 5 exposures using homemade light box. Used cameras auto exposure.
Bias: 5 exposures 1/4000 second of dark.
Stacked and combined in DeepSkyStacker.
Levels and contrast stretched in Photoshop 6.0 then converted to JPG.
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
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www.aznightsky.com
Scottsdale, AZ
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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Take a look at your flats to see if they show the dust specks.
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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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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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Thanks Dwight.
Unless I stretch my flats out I don't see any dust specks. With them stretched out I do see the same specks as on the image. I'm wondering if my exposures were too short / long on my flats. How does one judge the exposure of a flat?
Thanks again!
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
----------------------------
www.aznightsky.com
Scottsdale, AZ
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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Also what ISO was your camera set for?
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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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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9080
Loc: Cloud-chester,NY
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Been down that road too. Don't quit! You'll get it. I would skip the bias frames. I don't think your flats were properly applied either. Did you correct the luminance of them before applying them? With a modded camera, you need to. Maybe not in DSS???? But I would check into that. Also, where was the histogram hump for your lights?
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"Okay! You draw the straws. I'm-a taking the parachute."
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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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ISO 800 which is what I have used with success in the past.
Also I'm shooting from a fairly light polluted area. 2 minutes is about my maximum exposure with this setup.
Clearly there is something wrong with my flats and also probably something wrong with my processing.
I also took 2 hours worth of 2 minute exposures of M45 last night which turned out awful as well. 
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
----------------------------
www.aznightsky.com
Scottsdale, AZ
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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I set my camera to ISO 100 and TV mode, which gives me a speed of 1/5000 of a second exposure. I was having problems with my flats and tried this mode and it worked. Are your flats RAW?
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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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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9080
Loc: Cloud-chester,NY
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Quote:
I set my camera to ISO 100 and TV mode
This seems to be the Tonk standard. It works for me, too.
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"Okay! You draw the straws. I'm-a taking the parachute."
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9080
Loc: Cloud-chester,NY
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How did you focus?
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"Okay! You draw the straws. I'm-a taking the parachute."
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Qkslvr
Pooh-Bah
Reged: 06/23/06
Posts: 1316
Loc: NE Ohio, US
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Make sure your flats aren't clipping, they won't work right if they are, and you have to check each color channel.
I always use bias frames, and I usually reuse them. And DSS does have an option for matching temps. At some point if my subs get good enough, I'll worry more about matching temp.
Quote:
I set my camera to ISO 100 and TV mode, which gives me a speed of 1/5000 of a second exposure. I was having problems with my flats and tried this mode and it worked. Are your flats RAW?
At ISO 100 and 1/5000 of a second that has to be pretty close to as quick an exposure as your camera can do, right? I would think your light source is very close to being to bright.
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Mike
Onyx 80ED/N8/CG-5/40D
Edited by Qkslvr (01/11/08 12:56 PM)
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walt r
Post Laureate
Reged: 02/13/07
Posts: 3463
Loc: Doylestown, PA
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When looking at the histogram a flat should be about half the full well.
How were the flats processed and used? They should be normalized and divided into the bias and dark corrected lights.
Keep at it and it'll come together.
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Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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It seems that you would still have more image after an hour worth of time with that 160EDF scope.
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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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Dave M
Post Laureate
Reged: 08/03/04
Posts: 4928
Loc: N.E Ohio
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Quote:
Thanks Dwight.
Unless I stretch my flats out I don't see any dust specks.
Thanks again!
Chris,
Here`s what a typical RAW flat of mine looks like before
calibrated in Images Plus.
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Dave
Meade 16" F4.5 EQ Starfinder
Meade 10" SCT / Losmandy G11
Tak FSQ106ED
Canon 20D
SBig ST-4
http://www.spacew.com/gallery/image006006.html
Ps 19:1 The Heavens Declare the Glory of GOD.
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Mike D
scholastic sledgehammer
Reged: 08/15/07
Posts: 864
Loc: South GA
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I hope you don't mind me hijacking here, but I'm struggling with this also and hopefully someone has an answer.
I read in Jim Solomon's AP Cookbook at:
www.saratogaskies.com
of the necessity to take lights, darks, flats, AND dark-flats or flat-darks.
Anybody take flat-darks using DSS?
Or do you bother taking flat-darks?
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Vixen SXD
Vixen ED80Sf
Hutech 350D
STI Stiletto
Meade 2080
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Qkslvr
Pooh-Bah
Reged: 06/23/06
Posts: 1316
Loc: NE Ohio, US
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flat darks become important if you have to take long exposures to make your flats.
I make sky flats, and they are short enough I don't worry.
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Mike
Onyx 80ED/N8/CG-5/40D
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MartyT
professor emeritus
Reged: 09/28/07
Posts: 682
Loc: Kansas City
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(I'm just now figuring out this whole "flats" thing myself, so anyone should feel free to correct me if I'm wrong.)
Quote:
Unless I stretch my flats out I don't see any dust specks.
You won't - that's normal. Bring a flat image into Photoshop and do an "auto levels" -- you should be able to clearly see the dust and the vignetting. Don't save the image or anything, just use PS to check that it looks right.
If you didn't already, you should be using Tv for exposing the flats - that will adjust the exposure time automatically. I'd leave the ISO at 800 unless your light source is so bright that it saturates the image (check the back-of-the-camera histogram after taking the flat to see if it's fairly well centered.) -- I'd find a less-bright light source if you can't get a good exposure using the same ISO you're capturing your astro images
For me the first order of business seems to be building a light box of some sort; the "t-shirt over the objective" didn't really work well for me on the couple of occasions that I tried it...
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Celestron CGE / C-11 (CGE-1100)
Megrez 90 FD APO / 0.8x FR/FF vIII
QHY8, 350D, DSI Pro, SPC900NC
KWIQ Guider (QHY5)
ETX-125AT
12" Lightbridge
My Astrophoto Gallery
Astronomical Society of Kansas City
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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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Thanks everyone for you encouragement and advice.
Luke, I focused with a Stiletto IV. My daughter was bugging me while I was doing it so I don't think I did it as well as I would have liked.
I reprocessed my M45 and it looks better. It seems the flats worked this time.
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
----------------------------
www.aznightsky.com
Scottsdale, AZ
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Fabio Papa
Pooh-Bah
Reged: 03/01/05
Posts: 1460
Loc: Piacenza, Italy
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First of all, your images are far from garbage!
I don't know jack about flat frames as I never took one. But, flats aside, you seem to have an awful lot of things in front of your sensor. I mean, flat or not, I think a little cleaning is in order.
I'm also surprised all that stuff is invisible in the M45 shot. But maybe you exposed differently? And while on exposure matter, I would say, from a very light polluted site, you have either to change subject or invest in a good LPS filter. Else, you'll get a lot of frustration!
Anyway, don't give up! As I said, that's far from garbage!
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Fabio Papa
Celestron C8 F/10
Vixen ED81SWT F/7.7
Orion Atlas EQ-G
Gruppo Astrofili di Piacenza
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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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I reprocessed my horsehead and this time the flats seemed to work. Strange it didn't work the first time...
It still isn't my best work, but it is certainly better.
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Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
----------------------------
www.aznightsky.com
Scottsdale, AZ
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walt r
Post Laureate
Reged: 02/13/07
Posts: 3463
Loc: Doylestown, PA
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Big improvement Chris. It may have been just a fluke with the cal processing not opening the flat file. Nice to see that it now works. Sure is magic how all the dust donuts vanish.
Clear skies.
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Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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Great photo! Now try for 2 hours worth of subs..
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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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RogerRZ
Whatta you lookin' at?
Reged: 01/09/06
Posts: 2584
Loc: West Collette, NB, Canada
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If anybody is wondering what the difference between a modded and unmodded camera, here it is. Mine is unmodded, and notice how much more subdued the colors are.
A stack of 30X60 sec, iso1600, no darks, flats or bias frames. The mirror clips create terrible dark spikes. This ain't no refractor, lol!
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-Roger Pitre-
1 X 7 binocular Astro-Tech Imaging Newtonian MPCC
Starblast guidescope Starshoot autoguider
EQ6 Pro, HEQ5, Canon 50D, 70-200 f/4L
"He's got shoulders on him like a smelt..."--Anonymous
http://www.facebook.com/album.php?aid=10723&id=509325956&l=79d06a1d10
http://ajpobservatory.isgreat.org/
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Buzzer
professor emeritus
Reged: 07/21/07
Posts: 659
Loc: Long Island, NY
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Chris, with a clear dark sky clock like that, please don't quit. My pictures at the beginning and mostly still now, are not up to snuff. I am currently without a scope, that is a story for another time. set the camera to manual, set the iso to 100,keep changing the exposure time until the histogram peaks at 50%. I don't know why but I always take 30 flats. A bad flat will destroy a picture. That is the fun of this hobby, it is alike lot golf, you will hit that one good shot or 2 every round, but probobaly never master it, but trying so hard is where it's at, no quitting allowed. Please, repost the picture after you try this. Andy
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Meade SN-10 Carbon Fiber
TMB 92ss
Mini Borg 50 Guidescope
Celestron CGE Mount
QHY8
Orion Starshoot Autoguider
http://buzzer.zenfolio.com/
"I THINK THE WEATHERMAN NEEDS MORE EXPENSIVE EQUIPMENT"
WANING CRESCENT OBSERVATORY
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ChazK
Pooh-Bah
Reged: 11/23/05
Posts: 1453
Loc: Melbourne, Florida
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Chris,
Hang tough bro! I just tossed 2 hours of B33 myself due to excessive noise. That's a good effort and far from garbage! And if I may ask another question. There seems to be a lot of noise in your shot as well. Is that from it being a compilation of 2 minute sub-frames as opposed to longer exposures? Is it a signal to noise thing?
Chris...don't give up the ship. If we all took shots like Robert Gendler where would the fun be in that?
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D_talley
scholastic sledgehammer
Reged: 07/07/05
Posts: 890
Loc: Richmond VA
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A unmodified camera will react differently depending on the scope it is attached to. Here is the Horsehead also from an unmodified Canon 350d on a 14 inch scope. A lot more of the red is visible. I will not modify my camera because I get enough red for my taste. 50 minutes at ISO 800. When the camera is attached to my 4 inch, it has the same picture as Roger's.
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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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s58y
Postmaster
Reged: 12/12/04
Posts: 5509
Loc: Eastern NY
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It turned out to be a good image after all, especially for just 60 minutes unfiltered (I'm assuming).
If I were imaging the HH from a light-polluted site where 2 minutes at f/7.5 was the maximum exposure, I'd probably use a LP filter for RGB data, and also grab some h-alpha data shot through a narrowband filter to cut through the 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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Awesomelenny
Carpal Tunnel
Reged: 05/02/04
Posts: 2812
Loc: Long: 81.42 W Lat: 41.21 N
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I processed the fixed up image in NeatImage to get rid of some of the noise. How is this?
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Len
Meade 178 ED APO
127mm Astro_Tech ED APO
4" f/15 Model 166 Unitron with UNIWITT Pier
Televue Genesis SDF 101mm f/5.4
W.O. Zenithstar 66
2.4" f/15 Model 128C Unitron
Coronado Solarmax 90 DS Telescope
Losmandy Titan; G-11; all w/Gemini
All in a "Backyard Observatory"
"The heavens declare the glory of God; the skies proclaim the work of his hands."
Psalm 19:1
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cvedeler
Carpal Tunnel
Reged: 12/20/05
Posts: 2164
Loc: Scottsdale, AZ
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Len, that makes quite a difference. It really takes down the grainy noise without too severely impacting the resolution.
--------------------
Chris Vedeler
Astro-Physics 160EDF
Astro-Physics 900GTO
Q453HR / QHY8 CCD camera
Canon 450XSi
----------------------------
www.aznightsky.com
Scottsdale, AZ
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