Go Back   IceInSpace > Equipment > Astrophotography and Imaging Equipment and Discussions

Reply
 
Thread Tools Rate Thread
  #1  
Old 08-04-2008, 11:24 AM
jasonh
Registered User

jasonh is offline
 
Join Date: Feb 2008
Location: Auckland, New Zealand
Posts: 54
Experience using self guided camera on 4.5nm Ha?

Hi All, A bit of a continuation of my last question.

I need to get a new Ha filter, I am looking at custom scientific who have a 4.5nm and a 10nm.

I wonder if 10nm is too wide? I currently have a 7nm and am happy but it wont go in the stl11000. Astrodon is a jump up in price but could be more of a sweetspot at 6nm.

Anyway, the stl11k is self guided, does anyone have experience or success using a 4.5nm with the self guided cameras. Is it letting enough light through to aquire a guide star?

I will be using it initially with a tak fsq and then later with a 12.5" RC. When I get to that point I will have two scopes so can I use the other to guide. In the meantime, with only one scope, do you think the stl11k will have too hard a time guiding through the 4.5?

Thanks,
Jason
Reply With Quote
  #2  
Old 14-04-2008, 04:55 PM
Doomsayer
Registered User

Doomsayer is offline
 
Join Date: Apr 2006
Location: Newcastle
Posts: 222
ha guiding

Hi Jason
I'd say you will be fine in the more starry fields - I assume you are using the Paramount ME. I am currently running an ST8XME with self guiding through a 6nm astrodon filter - at the moment sitting behind a 12" SCT at f5. I am taking longer tracking exposures than normal however, 15 - 20 sec. The remote guide head is on my to buy list even so. The PME has such good unguided tracking that you will get away with longer guide exposures easily. I am easily managing 10 minutes unguided with this rig. Once I replace this SCT with a similar sized but slower RC I'd say I'll move up to a 6303E chip camera, which may or may not be SBIG. cheers, guy
Reply With Quote
  #3  
Old 14-04-2008, 05:22 PM
Bassnut's Avatar
Bassnut (Fred)
Narrowfield rules!

Bassnut is offline
 
Join Date: Nov 2006
Location: Torquay
Posts: 5,064
Hi Jason

Im used to a 15nm Ha filter, but just scored myself a 3nm. Yes its bit dimmer, but should still be guidable. The narrower filters are awesome, more structure detail, well worth the money. You would certainly be OK with a PME as guys says, what mount do you have?.
Reply With Quote
  #4  
Old 18-04-2008, 09:24 AM
jasonh
Registered User

jasonh is offline
 
Join Date: Feb 2008
Location: Auckland, New Zealand
Posts: 54
Hi guys, thanks for replying. In the end I went for the inbetween and got a 6nm astrodon.. It seemed like a good compromise.

With any luck the camera will be on a plane in a day and the filter a few days after that

Boy its been hard having my observatory finished and all working then finding myself without a camera for a couple of months. Time to get back in and brush out the cobwebs

Thanks,
Jason
Reply With Quote
  #5  
Old 18-04-2008, 03:03 PM
jase (Jason)
Registered User

jase is offline
 
Join Date: Sep 2006
Location: Melbourne, Victoria
Posts: 3,916
Just 2x2 bin the ST-237 guide chip to boost the sensitivity - "no brainer". If you're a Ha purist the 4.5nm is a lovely filter. I use the 10nm with the FSQ/STL11k. Its ok. Be careful with very fast optical systems such as camera lens (F/2.8 or F/4) and narrow bandpass filters. The angle at which the light strikes the lens is wider. This causes the Ha filter to shift its bandpass to a shorter wavelength. If the filter is very narrow, say 3nm, then it could miss the 656.3nm emission line altogether. You wont have problems with the FSQ or 12.5" RC with either of the filter selections you mention.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:24 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement