zwoof
sage
Reged: 06/11/07
Posts: 308
Loc: Triangle area NC, USA
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Here is my 101 from last night - CPC800, DSIpro, 18x1 min guided with Phd. I had hoped for better. I had dust and stuff on my glass and took flats today. I cannot get flats or bias to work. I tried ASIP, Nebulosity and Registax but no luck. The flats overwrite the lights and the bias turns everything black. Any help appreciated.
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Scott Greeson
CPC1100 XLT
DSI -C
AT65EQ
Philips SPC900NC
Canon T3 unmodded
HD wedge on homemade pier
My Site www.scottgreeson.com/astro.html
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KaibutsuX
super member
Reged: 08/23/07
Posts: 145
Loc: Fort Wayne, IN
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Not sure about the software, as I don't use any of it, but I do know that flats need to be taken at the same time as the lights WITHOUT ever touching or moving the telescope.
Also, I don't know if it's the processing or the exposure, but if your stars are that blown out then you're either exposing too long or overprocessing. I'm guessing its the processing as I don't think 1min would do this on M101, but it could be the DSI, I don't have experience with that either.
As far as the calibration, nothing should be overwriting the lights. And the bias frames should be black, but they get subtracted from the lights, not overwritten. Again, sorry I haven't used your software but I'm sure someone who has will chime in.
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ericjacob613
Photon Hog
Reged: 05/25/07
Posts: 5177
Loc: Santa Barbara CA
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Flats are not taken at the same time as lights. Darks are taken during the shooting session, using the same exposure length and ISO, but with the lens cap on.
Flats are taken without disturbing the optical setup, but they are made before darkfall or after daybreak, when the sky is light. Flats record any flaws in your optical system (vignetting and such). They also record any dust specks on your lenses or sensor.
There are other methods for making flats. Try a google search. There's a thread or two here on CN too.
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Y'all look at my flikr stuff:
http://www.flickr.com/photos/42129623@N04/
Canon XTI with 100,000 clicks on it, cheap Asian glass.
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ericjacob613
Photon Hog
Reged: 05/25/07
Posts: 5177
Loc: Santa Barbara CA
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Can you describe your procedure for shooting darks, flats and bias frames? This would help in diagnosing the problem.
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Y'all look at my flikr stuff:
http://www.flickr.com/photos/42129623@N04/
Canon XTI with 100,000 clicks on it, cheap Asian glass.
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zwoof
sage
Reged: 06/11/07
Posts: 308
Loc: Triangle area NC, USA
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I shoot darks right before lights and let Envisage subtract them. I shot the flats by pointing the scope at a white sheet and combining about 25 very short exposures. Bias was shot with the scope covered and combined 25 or so short exposures also. Thanks.
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Scott Greeson
CPC1100 XLT
DSI -C
AT65EQ
Philips SPC900NC
Canon T3 unmodded
HD wedge on homemade pier
My Site www.scottgreeson.com/astro.html
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thelittleman
Vendor (Peter's Actions)
Reged: 05/21/05
Posts: 4079
Loc: Hampshire, UK
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Scott - I don't really know what is going on with your processing problems. I am tempted to suggest IRIS, which is another (very good) piece of software, although it is extremely complicated. I have written a tutorial on my website on how to use it for basic pre-processing purposes.
Another suggestion would be to try an easier object. For me, M101 is my nemesis. I can never get it right. It is so dim it is really challenging to bring it out of the murk. This time of year is full of some bright objects - try M42 for example. There are various open clusters scattered around too 
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Clear Skies,
Peter
Photoshop Tutorials and Actions! New actions now added
Preprocessing in Iris Tutorial
http://peter-morris.magix.net/
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comets4tom
professor emeritus
Reged: 02/08/05
Posts: 638
Loc: Texas
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It also looks like the scope wasn't quite focused as indicated by the halos around the stars.
Tom
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Vixen R200SS,Meade 2045D, Orion Explorer 90mm, Orion Starblast Imaging Reflector, Vixen Great Polaris DX with iOptron Goto Nova, Meade LX200GPS 8 Inch, AT72ED
Canon 1000D,Orion Starshoot II Monochrome, Atik 16IC
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