A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Others » Astro Pictures
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

ASTRO: NGC 2244 (Rosette nebula)



 
 
Thread Tools Display Modes
  #11  
Old December 20th 06, 04:21 AM posted to alt.binaries.pictures.astro
Jon Christensen
external usenet poster
 
Posts: 40
Default ASTRO: NGC 2244 (Rosette nebula)

Nice widefield view of one of my favorite nebulas!


Jon Christensen

"Stefan Lilge" wrote in message
...
I recently used a night with exceptionally good transparency to image the
Rosette nebula. My only previous attempts on this object were done with my
Canon EOS300D DSLR camera and some closeups with small CCD chips that only
got a small part of the nebula.
This time I used a 200mm f/3.5 lens and was quite surprised how bright
this
object is when imaged with a "proper" CCD camera as it was tough with the
DSLR.

I will attach a "normal" version and a link to one where I used "drizzle
processing" in IRIS. The drizzled version shows more detail, but is also
noisier, so I reduced it's size (which was 2x original size) to 75% which
helped a bit. Unfortunately I lost one hour of data when the nebula was in
it's best position.

Taken from the middle of Berlin with a 200mm f/3.5 lens, SXV-H9 camera,
AStronomik 13nm Halpha filter, 30x5 minutes.

The images can also be found at
http://www.slilge.de/temp/2244-30x5gut.jpg
http://www.slilge.de/temp/2244-drizzle30x5gut.jpg

Stefan



  #12  
Old December 21st 06, 06:01 PM posted to alt.binaries.pictures.astro
Doug W.
external usenet poster
 
Posts: 264
Default ASTRO: NGC 2244 (Rosette nebula)

That one gets a Wow... Very fine image Stefan.

--
Regards, Doug W.
www.photonsfate.com
--


  #13  
Old December 22nd 06, 03:40 AM posted to alt.binaries.pictures.astro
George Normandin[_1_]
external usenet poster
 
Posts: 1,022
Default ASTRO: NGC 2244 (Rosette nebula)

"Rick Johnson" wrote
...
Thanks for the explanation. Not having used Drizzle I wasn't all that
familiar with it. I just posted my partial shot of this nebula. Came out
far better than I thought it would.
Rick


Rick, et al:

Drizzle takes advantage of info spread across the images to extract extra
resolution when you are forced to under sample. It was invented by the HST
guys back when the first camera really under-sampled. The price you have to
pay is getting at least 5 good exposures that are slightly shifted, and to
be prepared to handle noise. I've always wanted to fool around with it but I
haven't taken many under-sampled images. I'm glad to see what great results
Stefan got with it on this image.

George N


  #14  
Old December 22nd 06, 03:40 AM posted to alt.binaries.pictures.astro
George Normandin[_1_]
external usenet poster
 
Posts: 1,022
Default ASTRO: NGC 2244 (Rosette nebula)

"Rick Johnson" wrote

....... When the budget allows I'll have to get a good wide angle scope
to put atop the LX200R. I had the rings made so I can attach something up
there easily.........


Rick,

I don't know what you had in mind but I was thinking of getting one of
those new Meade 127mm APO's. However, a friend has good results with an old
Cave 6" F/4 Newt and a coma reducer. Perhaps a Meade 6" Schmidt Newt tube
would be a good and inexpensive "toy" for wide-field imaging? It would
probably need a new focuser, but lots of people buy them to get the mount
and then sell off the tube. At NEAF I was trying to get David Nagler to
discuss using Televue's new coma lens (designed to screw into the STL
cameras) with the Meade SNT's, but he said that he thought that the Meade
SNTs were already coma corrected. I had planned on using our "finder" (80mm
Brandon APO) on the 20RC but the focuser needs to be fixed and that won't
happen until next month.

George N


  #15  
Old December 22nd 06, 03:40 AM posted to alt.binaries.pictures.astro
George Normandin[_1_]
external usenet poster
 
Posts: 1,022
Default ASTRO: NGC 2244 (Rosette nebula)


"Stefan Lilge" wrote
...
I recently used a night with exceptionally good transparency to image the
Rosette nebula.........


Stefan,

Great image! The resolution in your 'drizzle' version is quite
impressive.

George N


  #16  
Old December 22nd 06, 06:16 AM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 2244 (Rosette nebula)



George Normandin wrote:
"Rick Johnson" wrote


....... When the budget allows I'll have to get a good wide angle scope
to put atop the LX200R. I had the rings made so I can attach something up
there easily.........



Rick,

I don't know what you had in mind but I was thinking of getting one of
those new Meade 127mm APO's. However, a friend has good results with an old
Cave 6" F/4 Newt and a coma reducer. Perhaps a Meade 6" Schmidt Newt tube
would be a good and inexpensive "toy" for wide-field imaging? It would
probably need a new focuser, but lots of people buy them to get the mount
and then sell off the tube. At NEAF I was trying to get David Nagler to
discuss using Televue's new coma lens (designed to screw into the STL
cameras) with the Meade SNT's, but he said that he thought that the Meade
SNTs were already coma corrected. I had planned on using our "finder" (80mm
Brandon APO) on the 20RC but the focuser needs to be fixed and that won't
happen until next month.

George N


As as stop gap measure I was thinking of that STL lens you mention with
my Optical Craftsman 6" f/4. I'll have to replace the spider as it is
warping so I couldn't keep it in collimation. Move the scope to the
other side of the meridian and it lost all collimation. It had been
adjusted so many times over the 45 years I've owned it it just won't
hold any more. The mirror in that scope is fantastic. It easily beat
the best RV-6 mirror of the era in our club at high power even with the
huge secondary. So if I can get it to hold collimation and that lens
works it would be a cheap way to go. As is, with the ST-7 it has almost
exactly the same FOV as the 14" with the STL-11000! So if you hear
anything about those at f/4 let me know. Think they are designed for
f/4.5. With the 11000's large chip that may not work at the corners.

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

  #17  
Old December 22nd 06, 04:51 PM posted to alt.binaries.pictures.astro
D van den H
external usenet poster
 
Posts: 35
Default ASTRO: NGC 2244 (Rosette nebula)

Stefan, Nice shot!
dirk

"Stefan Lilge" wrote in message
...
I recently used a night with exceptionally good transparency to image the
Rosette nebula. My only previous attempts on this object were done with my
Canon EOS300D DSLR camera and some closeups with small CCD chips that only
got a small part of the nebula.
This time I used a 200mm f/3.5 lens and was quite surprised how bright
this
object is when imaged with a "proper" CCD camera as it was tough with the
DSLR.

I will attach a "normal" version and a link to one where I used "drizzle
processing" in IRIS. The drizzled version shows more detail, but is also
noisier, so I reduced it's size (which was 2x original size) to 75% which
helped a bit. Unfortunately I lost one hour of data when the nebula was in
it's best position.

Taken from the middle of Berlin with a 200mm f/3.5 lens, SXV-H9 camera,
AStronomik 13nm Halpha filter, 30x5 minutes.

The images can also be found at
http://www.slilge.de/temp/2244-30x5gut.jpg
http://www.slilge.de/temp/2244-drizzle30x5gut.jpg

Stefan



  #18  
Old December 24th 06, 12:38 AM posted to alt.binaries.pictures.astro
George Normandin[_1_]
external usenet poster
 
Posts: 1,022
Default ASTRO: NGC 2244 (Rosette nebula)


"Rick Johnson" wrote

As as stop gap measure I was thinking of that STL lens you mention with my
Optical Craftsman 6" f/4. I'll have to replace the spider as it is
warping so I couldn't keep it in collimation. Move the scope to the other
side of the meridian and it lost all collimation. It had been adjusted so
many times over the 45 years I've owned it it just won't hold any more.
The mirror in that scope is fantastic. It easily beat the best RV-6
mirror of the era in our club at high power even with the huge secondary.
So if I can get it to hold collimation and that lens works it would be a
cheap way to go. As is, with the ST-7 it has almost exactly the same FOV
as the 14" with the STL-11000! So if you hear anything about those at f/4
let me know. Think they are designed for f/4.5. With the 11000's large
chip that may not work at the corners.


Rick,

You might have to put a new focuser on the 6-inch F/4 because focus is so
tight at that f-ratio. However, with the good mirror I'd bet that you could
get the OC scope to work with a coma lens. My friend with the Cave 6" F/4
put a Moonlight focuser on it and uses a coma corrector from Baader
(http://www.alpineastro.com/). He's using a camera with a chip about the
size of an ST-7's. However if the coma gets too much in the corners of the
STL-11k just cut the corners off! I got use to round images back in my days
of using a Lumicon 4x5" camera (3.8" circle of film exposed). You would get
a huge field even if you lost a little and it would be fun getting the old
6-inch scope working for imaging.

George N


  #19  
Old December 24th 06, 02:09 AM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 2244 (Rosette nebula)



George Normandin wrote:

"Rick Johnson" wrote


As as stop gap measure I was thinking of that STL lens you mention with my
Optical Craftsman 6" f/4. I'll have to replace the spider as it is
warping so I couldn't keep it in collimation. Move the scope to the other
side of the meridian and it lost all collimation. It had been adjusted so
many times over the 45 years I've owned it it just won't hold any more.
The mirror in that scope is fantastic. It easily beat the best RV-6
mirror of the era in our club at high power even with the huge secondary.
So if I can get it to hold collimation and that lens works it would be a
cheap way to go. As is, with the ST-7 it has almost exactly the same FOV
as the 14" with the STL-11000! So if you hear anything about those at f/4
let me know. Think they are designed for f/4.5. With the 11000's large
chip that may not work at the corners.



Rick,

You might have to put a new focuser on the 6-inch F/4 because focus is so
tight at that f-ratio. However, with the good mirror I'd bet that you could
get the OC scope to work with a coma lens. My friend with the Cave 6" F/4
put a Moonlight focuser on it and uses a coma corrector from Baader
(http://www.alpineastro.com/). He's using a camera with a chip about the
size of an ST-7's. However if the coma gets too much in the corners of the
STL-11k just cut the corners off! I got use to round images back in my days
of using a Lumicon 4x5" camera (3.8" circle of film exposed). You would get
a huge field even if you lost a little and it would be fun getting the old
6-inch scope working for imaging.

George N


It isn't a coma problem at the corners, but a curvature problem. If
focus is dead on there is no distortion at the corners. It happens only
if the center is focused in to the maximum F/10 allows. That puts the
corners just barely at the out extreme of focus. If it cools any the
focus moves out just a tad and there go the corners but the center is
fine. Robo-Focus's temp compensation handles this when I can get it to
turn on. If I can't then I just have to manually focus and cross my
fingers.

6" F/4 already has a JMI motor focus on it that is run by the Paramount.
It works very well. I used it as my scope for a couple months waiting
for the LX200R OTAs to hit the market. For a while Meade only sold them
on their fork mount. Scope was nice and fast and with the ST-7 had
almost exactly the same FOV as the LX200R with the STL-11000 but usually
no sooner did I collimate the spider than I'd park the scope to roll the
roof and that motion would cause it to go out of whack again. Gave me
large stars on the right side of most images as the field was tilted.

I've got to replace that spider before I try the lens and make sure it
will hold in place. To fully illuminate the STL-11000 I'll need an even
larger secondary. Might just live with the vignetting and flat field it
out.

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ASTRO: Rosette Nebula Robert Price Astro Pictures 10 November 25th 06 10:06 PM
The Rosette Nebula [email protected] Misc 0 April 10th 05 03:54 PM
Dust Sculptures in the Rosette Nebula Shawn Amateur Astronomy 0 January 13th 05 06:08 PM
Rosette Nebula: Stellarvue/TMB 105 & Canon 10D Stephen Pitt Amateur Astronomy 0 February 23rd 04 12:35 AM
Fitful Young Star Sputters to Maturity in the Rosette Nebula (Forwarded) Andrew Yee Astronomy Misc 0 January 26th 04 02:50 PM


All times are GMT +1. The time now is 10:22 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.