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DSI strangeness



 
 
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  #1  
Old November 10th 07, 10:33 PM posted to alt.binaries.pictures.astro
Eric[_1_]
external usenet poster
 
Posts: 18
Default DSI strangeness

Hey folks,

I finally got to looking at some of my DSI-Pro frames from August. I've
got this odd interlacing pattern in my images. I've attached a typical
image here. There's been no contrast enhancing, etc. Just a shot of
Plato. A total of 3 images stacked up, 0.0018 exposure each. Using
Meade Envisage software, no dark or flat correction, 8" LX200 at prime
focus.

Any ideas what would cause this ? I haven't seen it in other DSI images
on the net.

Eric.

--
"I feel like I am being nibbled to death by a cat" -Londo Molari


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  #2  
Old November 10th 07, 11:41 PM posted to alt.binaries.pictures.astro
J.Warren
external usenet poster
 
Posts: 55
Default DSI strangeness

Eric,
Try reposting your question with "ASTRO" in the title. A lot of guys
won't see your post due to filtering unless it has "Astro" in the title. I
don't know about the DSI but to me it looks like the lines might be caused
by gain being too high. I've ran into those before with planetary imaging.
Also, the more frames you stack, the less noise, and those lines, you will
have.

Joel

"Eric" wrote in message
news:7tpZi.20702$h57.14528@edtnps89...
Hey folks,

I finally got to looking at some of my DSI-Pro frames from August. I've
got this odd interlacing pattern in my images. I've attached a typical
image here. There's been no contrast enhancing, etc. Just a shot of
Plato. A total of 3 images stacked up, 0.0018 exposure each. Using
Meade Envisage software, no dark or flat correction, 8" LX200 at prime
focus.

Any ideas what would cause this ? I haven't seen it in other DSI images
on the net.

Eric.

--
"I feel like I am being nibbled to death by a cat" -Londo Molari




  #3  
Old November 11th 07, 02:07 AM posted to alt.binaries.pictures.astro
Eric[_1_]
external usenet poster
 
Posts: 18
Default ASTRO: DSI strangeness

Eric wrote:

Reposting - forgot to add 'ASTRO'...
Hey folks,

I finally got to looking at some of my DSI-Pro frames from August.
I've got this odd interlacing pattern in my images. I've attached a
typical image here. There's been no contrast enhancing, etc. Just a
shot of Plato. A total of 3 images stacked up, 0.0018 exposure each.
Using Meade Envisage software, no dark or flat correction, 8" LX200 at
prime focus.

Any ideas what would cause this ? I haven't seen it in other DSI
images on the net.

Eric.


------------------------------------------------------------------------



--
"I feel like I am being nibbled to death by a cat" -Londo Molari
  #4  
Old November 11th 07, 02:09 AM posted to alt.binaries.pictures.astro
Eric[_1_]
external usenet poster
 
Posts: 18
Default DSI strangeness

Hi Joel,

Oops.

I left the gain, offset at the default settings. I'll try again next
time I get some clear sky.

Eric.

J.Warren wrote:
Eric,
Try reposting your question with "ASTRO" in the title. A lot of guys
won't see your post due to filtering unless it has "Astro" in the title. I
don't know about the DSI but to me it looks like the lines might be caused
by gain being too high. I've ran into those before with planetary imaging.
Also, the more frames you stack, the less noise, and those lines, you will
have.

Joel

"Eric" wrote in message
news:7tpZi.20702$h57.14528@edtnps89...

Hey folks,

I finally got to looking at some of my DSI-Pro frames from August. I've
got this odd interlacing pattern in my images. I've attached a typical
image here. There's been no contrast enhancing, etc. Just a shot of
Plato. A total of 3 images stacked up, 0.0018 exposure each. Using
Meade Envisage software, no dark or flat correction, 8" LX200 at prime
focus.

Any ideas what would cause this ? I haven't seen it in other DSI images
on the net.

Eric.

--
"I feel like I am being nibbled to death by a cat" -Londo Molari








--
"I feel like I am being nibbled to death by a cat" -Londo Molari
  #5  
Old November 11th 07, 06:12 PM posted to alt.binaries.pictures.astro
Stefan Lilge
external usenet poster
 
Posts: 2,269
Default ASTRO: DSI strangeness

Eric,

the DSI Pro (I have one as a backup-autoguider) has an interline CCD chip,
where odd and even lines of pixels are read after another, which means that
odd lines get a bit more exposure time than even lines (or vice versa). This
is usually no problem on longer exposures, but makes such cameras a bad
choice for short exposures as used for planets or the moon.
The only way around this is to do 2xbinning, which of course will lower the
resolution of the image. AstroArt has some software filters to fix the
"banding", but this does not work too well.
You could also stack a lot of images, if the field of view shifts a bit
during the series, the "banding" might even out.

Stefan

"Eric" schrieb im Newsbeitrag
news:jBsZi.15110$8S5.4521@edtnps82...
Eric wrote:

Reposting - forgot to add 'ASTRO'...
Hey folks,

I finally got to looking at some of my DSI-Pro frames from August. I've
got this odd interlacing pattern in my images. I've attached a typical
image here. There's been no contrast enhancing, etc. Just a shot of
Plato. A total of 3 images stacked up, 0.0018 exposure each. Using Meade
Envisage software, no dark or flat correction, 8" LX200 at prime focus.

Any ideas what would cause this ? I haven't seen it in other DSI images
on the net.

Eric.


------------------------------------------------------------------------



--
"I feel like I am being nibbled to death by a cat" -Londo Molari


  #6  
Old November 11th 07, 07:14 PM posted to alt.binaries.pictures.astro
Eric[_1_]
external usenet poster
 
Posts: 18
Default ASTRO: DSI strangeness

Ok. So since the problem depends on what you're imaging, flat-fielding
wont fix it. That's dumb. I guess the LPI is NOT an interline chip ?

Eric.

Stefan Lilge wrote:
Eric,

the DSI Pro (I have one as a backup-autoguider) has an interline CCD
chip, where odd and even lines of pixels are read after another,
which means that odd lines get a bit more exposure time than even
lines (or vice versa). This is usually no problem on longer exposures,
but makes such cameras a bad choice for short exposures as used for
planets or the moon.
The only way around this is to do 2xbinning, which of course will
lower the resolution of the image. AstroArt has some software filters
to fix the "banding", but this does not work too well.
You could also stack a lot of images, if the field of view shifts a
bit during the series, the "banding" might even out.

Stefan

"Eric" schrieb im Newsbeitrag
news:jBsZi.15110$8S5.4521@edtnps82...
Eric wrote:

Reposting - forgot to add 'ASTRO'...
Hey folks,

I finally got to looking at some of my DSI-Pro frames from August.
I've got this odd interlacing pattern in my images. I've attached a
typical image here. There's been no contrast enhancing, etc. Just a
shot of Plato. A total of 3 images stacked up, 0.0018 exposure
each. Using Meade Envisage software, no dark or flat correction, 8"
LX200 at prime focus.

Any ideas what would cause this ? I haven't seen it in other DSI
images on the net.

Eric.


------------------------------------------------------------------------




--
"I feel like I am being nibbled to death by a cat" -Londo Molari




--
"I feel like I am being nibbled to death by a cat" -Londo Molari
  #7  
Old November 12th 07, 07:59 PM posted to alt.binaries.pictures.astro
Stefan Lilge
external usenet poster
 
Posts: 2,269
Default ASTRO: DSI strangeness

Eric, I don't really know about the LPI, but I guess it should work (as it
is advertised for moon and planets).

Stefan

"Eric" schrieb im Newsbeitrag
news:TDHZi.39341$XF6.2438@edtnps90...
Ok. So since the problem depends on what you're imaging, flat-fielding
wont fix it. That's dumb. I guess the LPI is NOT an interline chip ?

Eric.

Stefan Lilge wrote:
Eric,

the DSI Pro (I have one as a backup-autoguider) has an interline CCD
chip, where odd and even lines of pixels are read after another, which
means that odd lines get a bit more exposure time than even lines (or
vice versa). This is usually no problem on longer exposures, but makes
such cameras a bad choice for short exposures as used for planets or the
moon.
The only way around this is to do 2xbinning, which of course will lower
the resolution of the image. AstroArt has some software filters to fix
the "banding", but this does not work too well.
You could also stack a lot of images, if the field of view shifts a bit
during the series, the "banding" might even out.

Stefan

"Eric" schrieb im Newsbeitrag
news:jBsZi.15110$8S5.4521@edtnps82...
Eric wrote:

Reposting - forgot to add 'ASTRO'...
Hey folks,

I finally got to looking at some of my DSI-Pro frames from August. I've
got this odd interlacing pattern in my images. I've attached a typical
image here. There's been no contrast enhancing, etc. Just a shot of
Plato. A total of 3 images stacked up, 0.0018 exposure each. Using
Meade Envisage software, no dark or flat correction, 8" LX200 at prime
focus.

Any ideas what would cause this ? I haven't seen it in other DSI images
on the net.

Eric.


------------------------------------------------------------------------




--
"I feel like I am being nibbled to death by a cat" -Londo Molari




--
"I feel like I am being nibbled to death by a cat" -Londo Molari


 




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