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Re: [APML] OT: Deep M81 (12 Hours) (My image...really!)
Hi Kevin,
Perhaps you are saving a RGB color FITS with PixInsight. Very few programs
out there are able to work with multichannel FITS. If this is the case, try
extracting the luminance, save it, and load it into CCDSharp. Anyway, you
should not deconvolve the chrominance of your images.
If you are already saving a grayscale image as FITS with PixInsight, maybe
CCDSharp is not able to deal with some header keywords. Try saving the file
in 16-bit signed integer format. This is the most widely used FITS format.
Another problem can be an embedded ICC profile. If when you save the FITS
you see the "Embed ICC Profile" check box checked, uncheck it. Again, this
is an advanced option that CCDSharp probably will not be able to deal with.
PixInsight relies on the CFITSIO library by NASA/Goddard, so full
conformance with the FITS standard is guaranteed.
Hope this helps; please let me know.
Juan
__________________________________________________________________
Juan Conejero, Pleiades Astrophoto Team
PixInsight Home Page: http://pleiades-astrophoto.com/pixinsight/
__________________________________________________________________
----- Original Message -----
From: "Kevin Wigell" <kwemail@twcny.rr.com>
To: "APML" <astro-photo@seds.org>
Sent: Sunday, March 13, 2005 1:28 PM
Subject: Re: [APML] OT: Deep M81 (12 Hours) (My image...really!)
> George, I thought this would work for me, but alas, not. When I open a
> tiff image in PixInsight and then save it in FITS format, I'm not able to
> open the FITS file in CCDSharp. I get "An unknown error occurred while
> accessing (filename)" from CCDSharp. But, I am able to open the very same
> FITS file in Photoshop CS.
>
> There are quite a few options in PixInsight for FITS options when saving
> (8-bit unsigned integer, 16-bit unsigned integer, 16-bit signed integer,
> etc), none of which mean much to me. Does anyone have any idea what the
> problem might be (besides me)?
>
> Kevin Wigell
> www.kwastronomy.com
>
> ----- Original Message -----
> From: "George Anderson" <tillerman1@videotron.ca>
> To: "Kevin Wigell" <kwemail@twcny.rr.com>; "Discussion of Film
> Astrophotography" <astro-photo@seds.org>
> Sent: Saturday, March 12, 2005 22:21
> Subject: Re: [APML] OT: Deep M81 (12 Hours) (My image...really!)
>
>
>> Hi Kevin
>>
>> I believe that pixinsight will allow you to save a file in FITS format.
>> So you could read whatever fileformat you have into pixinsight and then
>> save it as fits.
>>
>> George Anderson
>> Montreal Canada
>>
>> Clear skies and good health
>>
>> Kevin Wigell wrote:
>>>
>>> Rob, CCDSharp will only read FITS or SBIG formats, correct? How do you
>>> get
>>> your file into one of those formats so that CCDSharp can read it?
>>>
>>> Kevin Wigell
>>> www.kwastronomy.com
>>>
>>> ----- Original Message -----
>>> From: "Robert Gendler" <robgendler@worldnet.att.net>
>>> To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
>>> Sent: Saturday, March 12, 2005 8:04
>>> Subject: Re: [APML] OT: Deep M81 (12 Hours) (My image...really!)
>>>
>>> > Bobby,
>>> > Deconvolution algorthms are complex mathematical formulas that
>>> > try to approximate what the image would look like without the blurring
>>> > effects brought on by seeing, mechanical and optical issues. Its much
>>> > more than a sharpening filter. It does an amazing job of tightening an
>>> > image
>>> > but does come at a cost. The image needs to have good S/N as decon
>>> > will bring out noise in the image, particularly the background
>>> > (mottling).
>>> > The stars will also acquire halos with aggressive decon. One thing I
>>> > should
>>> > mention is that for an image to respond well to decon it must be
>>> > oversampled
>>> > which is another way of saying it needs to be taken at long focal
>>> > length,
>>> > at
>>> > least 2000mm. There are ways to deal with the noise such as making a
>>> > layer
>>> > with a nondecon frame to replace the background and stars. The Lucy
>>> > Richardson algorthms IMO are the best. I use CCDSharp (now free off
>>> > the SBIG site). I hope this helps.
>>> >
>>> >
>>> > Rob Gendler
>>> > email: robgendler@att.net
>>> > Web Site: http://www.robgendlerastropics.com
>>>
>>> _______________________________________________
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>>> http://seds.org/mailman/listinfo/astro-photo
>
>
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