#1  
Old 07-10-2013, 12:36 PM
kosh's Avatar
kosh (Goran)
Registered User

kosh is offline
 
Join Date: Sep 2005
Location: Melbourne
Posts: 312
2" T-Adaptors

Hi all,

Just wondering if anyone can tell me whether I would benefit at all by using
a 2" T-Adaptor over the 1.25" T-Adaptor that came with my scope.
I plan on using my canon 450D through a SW ED80 for DSO astro-imaging.

Cheers.
Reply With Quote
  #2  
Old 07-10-2013, 02:10 PM
RobF's Avatar
RobF (Rob)
Mostly harmless...

RobF is offline
 
Join Date: Jul 2008
Location: Brisbane, Australia
Posts: 5,513
2" will produce a LOT less vignetting - that's the standard most people use
Reply With Quote
  #3  
Old 07-10-2013, 02:40 PM
mithrandir's Avatar
mithrandir (Andrew)
Registered User

mithrandir is offline
 
Join Date: Jan 2009
Location: Glenhaven
Posts: 4,161
A standard 2" T-adaptor works with minimal vingetting for crop frame cameras. For a full frame a CNC Ultrawide should be better as it is a one piece device and does not have the 1.5" restriction caused by the threaded section. I've just ordered one.
Reply With Quote
  #4  
Old 07-10-2013, 03:06 PM
doppler's Avatar
doppler (Rick)
Registered User

doppler is offline
 
Join Date: Nov 2012
Location: Mackay
Posts: 1,542
I have a 450D (crop frame sensor) and a 102mm f7 achro and have had no vignetting problems with the 1.25" adaptor. I think that it is more of a problem with full frame sensors.
Reply With Quote
  #5  
Old 07-10-2013, 03:23 PM
mithrandir's Avatar
mithrandir (Andrew)
Registered User

mithrandir is offline
 
Join Date: Jan 2009
Location: Glenhaven
Posts: 4,161
Quote:
Originally Posted by doppler View Post
I have a 450D (crop frame sensor) and a 102mm f7 achro and have had no vignetting problems with the 1.25" adaptor. I think that it is more of a problem with full frame sensors.
It also depends on the f-ratio. Faster scopes are more likely to vingette.
Reply With Quote
  #6  
Old 07-10-2013, 07:09 PM
acropolite's Avatar
acropolite (Phil)
Registered User

acropolite is offline
 
Join Date: Feb 2005
Location: Launceston Tasmania
Posts: 8,988
The SW reducer flattener is a worthwhile addition to the ED80 with the associated wide T ring there's no vignetting on FF should you upgrade in the future.
Reply With Quote
  #7  
Old 08-10-2013, 12:02 AM
kosh's Avatar
kosh (Goran)
Registered User

kosh is offline
 
Join Date: Sep 2005
Location: Melbourne
Posts: 312
Thanks for your replies everyone.
I'm going to have to see if I have any issues when I actually get to use the scope for imaging, seeing as it's been cloudy every night since I got it. I was going to order a variable projection adaptor, thought I might get the larger t-adaptor and save shipping while I'm at it.
I think my scope is an f7.5. That's medium fast isn't it?
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 04:16 AM.

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