#1  
Old 23-07-2013, 06:42 PM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
Lrgb/nb noob

That'd be me

I bought today an older TEC and water cooled SBIG St8XE with the CFW-8 filter wheel off the trader. I am going to be purchasing a 1/25" LRGB set to go with it (undecided brand at this point in time), but was wondering...

I need to save a little money here, and the 1.25" H-a filters run $190 each. I already have a 2" H-a filter, so is there anything stupid about this proposition:
Finish LRGB with the 1.25" set (parfocals). When done, remove FW and install the 2" H-a filter directly to the nosepiece, refocus, and image that way (I also have already a 2" OIII, plus a 1.25" OIII).

Any issues with this and later integrating the H-a into the LRGB? Will there be any image scale shift doing it this way? Or should I stop being a cheapskate and just fork out for a 1.25" H-a
Reply With Quote
  #2  
Old 23-07-2013, 06:55 PM
rogerco's Avatar
rogerco (Roger)
Roger

rogerco is offline
 
Join Date: Sep 2007
Location: Woodford,NSW,Australia
Posts: 388
I'm in the situation of having an 1.25 Ha filter but needing a 2" Ha are you interested in some sort of a swap?
Reply With Quote
  #3  
Old 23-07-2013, 07:27 PM
RobF's Avatar
RobF (Rob)
Mostly harmless...

RobF is offline
 
Join Date: Jul 2008
Location: Brisbane, Australia
Posts: 5,513
Certainly nothing to stop you putting the 2" filters elsewhere in the light path. I have only 5 slots in my FW so often leave one slot blank and put the 2" NB filters on my 2" nosepiece. You're typically shooting hours (or even nights) worth of data so its not like you're flicking filters every few minutes with NB once you've focused.

I don't like doing it, but the other option is rotate to the L slot and put the 2" NB on the nosepiece - again as long as you focus then shoot with the same configuration.
Reply With Quote
  #4  
Old 23-07-2013, 07:49 PM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
Thanks Rob - exactly what I thought. Considering the H-a will be several nights worth, along with the OIII, I cannot see a general issue with it. Then just do the LRGB with the FW attached.

Roger, what brand of filter? I may be interested.
Reply With Quote
  #5  
Old 26-07-2013, 07:09 AM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
I ended up purchasing Astronomik filters. SHould be a wise choice I think.

LRGB, plus H-a. The OIII I have in Orion, so will have to refocus for that one. No drama.

Now to sell my unused 2" OIII
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 07:42 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
SkyWatcher Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
Lunatico Astronomical
Advertisement
Meade Australia
Advertisement
NexDome Observatories
Advertisement
Celestron Australia
Advertisement
Astronomy and Electronics Centre
Advertisement