Return to the Cloudy Nights Telescope Reviews home page


Astrophotography and Sketching >> CCD Imaging & Processing

Pages: 1
Bert
professor emeritus


Reged: 02/17/06

Loc: Australia
Orions Sword in 3nm NII new
      #5569841 - 12/13/12 07:57 PM Attachment (20 downloads)

Managed to get 10x16 minutes in 3nm NII of M42 and made a mosaic with the earlier Horse head data. There is a mismatch at the overlap but it gives an idea of what is possible.

Large image 5MB FoV 6.0 X 3.4 degrees.

http://d1355990.i49.quadrahosting.com.au/2012_12/Orsword_NII.jpg

I am finding that gradients are still a problem even with 3nm filters.

Bert

Astrograph is an Officina Stellare RH200 which has a focal length of 600mm and is F3, yes F3! Clear aperture is 200mm.
FLI Atlas Focuser.
FLI ten position filter wheel CFW-3-10 with 50mm square filters.
Astrodon E series LRGB and HA, NII, SII and OIII 3nm NB filters. Also a continuum filter 5nm.
Camera is a FLI PL16803 which has a sensor size 36.8 X 36.8 mm.
The FoV of this system is 3.5 X 3.5 degrees.
Mount is a Software Bisque PMX.

Edited by Bert (12/13/12 08:01 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
SL63 AMG
scholastic sledgehammer
*****

Reged: 12/21/09

Loc: Williamson, Arizona
Re: Orions Sword in 3nm NII new [Re: Bert]
      #5569847 - 12/13/12 08:03 PM

That's amazing!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Kildar13x
member


Reged: 07/06/11

Loc: Maine
Re: Orions Sword in 3nm NII new [Re: SL63 AMG]
      #5569864 - 12/13/12 08:12 PM



Post Extras: Print Post   Remind Me!   Notify Moderator  
broca
Carpal Tunnel
*****

Reged: 03/26/10

Loc: Ocala, FL
Re: Orions Sword in 3nm NII new [Re: Kildar13x]
      #5569922 - 12/13/12 08:40 PM

Amazing amount of dust you were able to capture and process out. Well done!

Post Extras: Print Post   Remind Me!   Notify Moderator  
psandelle
professor emeritus


Reged: 06/18/08

Loc: Los Angeles
Re: Orions Sword in 3nm NII new [Re: broca]
      #5569953 - 12/13/12 09:03 PM

WHOA!!!!

Nice pic!

Paul


Post Extras: Print Post   Remind Me!   Notify Moderator  
rigel123
Postmaster
*****

Reged: 06/29/09

Loc: SW Ohio
Re: Orions Sword in 3nm NII new [Re: Bert]
      #5570013 - 12/13/12 09:47 PM

That is simply unreal!! Amazing!

Post Extras: Print Post   Remind Me!   Notify Moderator  
David PavlichAdministrator
Transmographied
*****

Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Orions Sword in 3nm NII [Re: rigel123]
      #5570060 - 12/13/12 10:18 PM

That's a terrific image!

David


Post Extras: Print Post   Remind Me!   Notify Moderator  
freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: Orions Sword in 3nm NII new [Re: Bert]
      #5570451 - 12/14/12 08:30 AM

Hi-

That's a nice image and it has potential, but I would be concerned that the mismatch is related to using 3nm at f/3 with wide field. Trying to separate Ha from Nii is fundamentally difficult with fast optics, and due to the large and variable angles through the filter, I would expect a variation in the ratio of Ha/Nii across the image. In a single image this wouldn't show much, even though it is present - but in a montage, any difference in this ratio would produce a mismatch.

I can't say for sure that is what is happening here, but some amount of variable mixing is inevitable across the image at fast f/ratio. I don't think there is a way to fully isolate Ha from Nii with fast optics - you either have to go wider band and combine them, or slower f/ratio to keep them separate.

This effect also may be related to your issue with gradients.

Frank


Post Extras: Print Post   Remind Me!   Notify Moderator  
Konihlav
Pooh-Bah


Reged: 03/05/09

Re: Orions Sword in 3nm NII new [Re: freestar8n]
      #5570619 - 12/14/12 10:38 AM

Bert - what a nice contrast :-) great!

Frank - I would not be afraid of F/3 and 3nm NII as the Astrodon filter is really ubercool (simply great!), but you are right that even that the Astrodon filters have very high transmittance and steep/narrow bandwith there probabably is some small % of Ha emission included in the image as the 658nm of NII in 3nm allows to pass light in between 656.5nm to 659.5nm in ideal case... and Ha is 656.3 if I am right... so the small % may be eventually 50% ;D who knows

so good point! with slower scope it would be much better separated, but who cares in ORION ;D


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1


Extra information
16 registered and 16 anonymous users are browsing this forum.

Moderator:  Oldfield, droid, bilgebay, WOBentley, dr.who 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 480

Jump to

CN Forums Home




Cloudy Nights Sponsor: Astronomics