#1  
Old 04-05-2010, 07:36 PM
TrevorW
Registered User

TrevorW is offline
 
Join Date: Aug 2006
Location: Western Australia
Posts: 7,852
Focusing for HA

When using a HA filter do you focus as normal first then attach the filter or focus with the filter in place

Reply With Quote
  #2  
Old 04-05-2010, 07:44 PM
dugnsuz's Avatar
dugnsuz (Doug)
Registered User

dugnsuz is offline
 
Join Date: Aug 2005
Location: Hahndorf, South Australia
Posts: 4,261
Pasting this from a recent post of mine...

Ha isn't the easiest on a DSLR that's for sure - checking focus between each shot in the absence of a bright star in the FOV is going to be a nachtmare!!!!http://www.iceinspace.com.au/forum/....milies/lol.gif
I developed a little routine to help with the "user" program of Synscan which makes life a tad easier (just a tad mind!!) Find a bright star without Ha filter - set it as user object 1. GoTo and Frame the object you want to image - set it as user object 2. Go back to obj 1 (bright star), insert Ha filter into imaging train, focus, slew back to obj 2 - start imaging!!!! Simple Eh!?http://www.iceinspace.com.au/forum/..../rolleye09.gif
(I'm using EOS clip in filters on my 40D Trevor)
The bugger is that if you use this to method to focus in-between shots, you stuff around with the guiding a bit too much.
Doug
Reply With Quote
  #3  
Old 04-05-2010, 07:59 PM
TrevorW
Registered User

TrevorW is offline
 
Join Date: Aug 2006
Location: Western Australia
Posts: 7,852
Thanks Dougie yeah I thought I'd have to focus is place maybe try with a Bahitov on a bright star
Reply With Quote
  #4  
Old 05-05-2010, 09:30 PM
Tandum's Avatar
Tandum (Robin)
Registered User

Tandum is offline
 
Join Date: Apr 2008
Location: Wynnum West, Brisbane.
Posts: 4,161
Trevor, Just put the filter in and plonk the mask on the front of the scope and up binning to 2x. Draw a box around the brightest star in the image and get a sub image and then increase exposure time till you see the lines from the mask. Now focus.
Reply With Quote
  #5  
Old 05-05-2010, 10:43 PM
dugnsuz's Avatar
dugnsuz (Doug)
Registered User

dugnsuz is offline
 
Join Date: Aug 2005
Location: Hahndorf, South Australia
Posts: 4,261
Quote:
Originally Posted by Tandum View Post
Trevor, Just put the filter in and plonk the mask on the front of the scope and up binning to 2x. Draw a box around the brightest star in the image and get a sub image and then increase exposure time till you see the lines from the mask. Now focus.
Another reason to dump the DSLR - D'Oh!!!!
Reply With Quote
  #6  
Old 05-05-2010, 10:50 PM
Tandum's Avatar
Tandum (Robin)
Registered User

Tandum is offline
 
Join Date: Apr 2008
Location: Wynnum West, Brisbane.
Posts: 4,161
To be honest doug the mask lines are better defined in 1X and blocky as hell in 4x but getting a sub image with longer exposures is the key and you can do that with a dslr and the right software
Reply With Quote
  #7  
Old 06-05-2010, 03:55 PM
TrevorW
Registered User

TrevorW is offline
 
Join Date: Aug 2006
Location: Western Australia
Posts: 7,852
Thanks Robin didn't increase the binning but just did a longer exposure
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 06:54 AM.

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