#1  
Old 06-06-2013, 12:05 PM
E_ri_k (Erik)
Registered User

E_ri_k is offline
 
Join Date: Jun 2011
Location: Lakes Entrance
Posts: 809
Focal reducer

Hey guys. I have a AP CCDT67 reducer for my RC10. It's been sitting around for a while, and I figured I better try get it to work with my stuff. I have calculated all my distances to the focal point, etc, and worked out what reductions I can achieve.

Now for the sill question, for anyone with the same reducer. Which way does it go in the optical path....Does the male thread go on the scope side, or the camera side??

Erik
Reply With Quote
  #2  
Old 06-06-2013, 03:12 PM
allan gould's Avatar
allan gould
Registered User

allan gould is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 4,481
Erik
the spacing for theccdt67 is 101mm exactly. you allow 16mm for the FR itself and then the rest of the distance is made up to 101mm. see the following pdf (http://www.astro-physics.com/tech_su...r-techdata.pdf).
My QHY10 has a 20mm space between the t thread and ccd chip and so adding the 16 to 20mm gives 36 and leaves 65mm spacing needed. I made this up with a 10mm+30mm T spacers and a 25 mm 2" nose piece as in the photo attached.
Hope this makes sense re orientation and spacing. This gives me perfectly round stars with either the qhy10 or QSI583 camera (but for the latter camera I have to remove the 30mm spacer as the chip to t spacing is 50 mm for the QSI583).
Allan
Attached Thumbnails
Click for full-size image (DSC00001.JPG)
66.3 KB36 views
Reply With Quote
  #3  
Old 06-06-2013, 05:04 PM
E_ri_k (Erik)
Registered User

E_ri_k is offline
 
Join Date: Jun 2011
Location: Lakes Entrance
Posts: 809
Thanks Allan. Yeah that all makes sense. I was using the formula of the AP website to calculate the distances. The reducers FL-distance to sensor/reducers FL, so (305-D)/305. My understanding was that 101mm is the optimum measurement, to give a .67x reduction, but the greater the distance, the greater the reduction? Or did I understand that wrong


I am am planning on using the reducer in front of my ONAG. So I need to get some adapters and threads and things, because everything is a different thread of coarse but I'll be able to make it 101mm pretty easily I think.....

So by your picture, I'm guessing the camera goes on the end of your extensions?

Erik
Reply With Quote
  #4  
Old 06-06-2013, 06:33 PM
allan gould's Avatar
allan gould
Registered User

allan gould is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 4,481
Quote:
Originally Posted by E_ri_k View Post
Thanks Allan. Yeah that all makes sense. I was using the formula of the AP website to calculate the distances. The reducers FL-distance to sensor/reducers FL, so (305-D)/305. My understanding was that 101mm is the optimum measurement, to give a .67x reduction, but the greater the distance, the greater the reduction? Or did I understand that wrong


I am am planning on using the reducer in front of my ONAG. So I need to get some adapters and threads and things, because everything is a different thread of coarse but I'll be able to make it 101mm pretty easily I think.....

So by your picture, I'm guessing the camera goes on the end of your extensions?

Erik
Eric
Read David Cortners website about the ccdt67 and spacing as he has got it down to f5 with different spacing and still gets round stars
http://www.davidcortner.com/slowblog/20110815c.php
You are correct in that the camera goes on the end of the T spacers. If I use the Qhy then the setup as shown is used as is but if I use the QSI then I remove the 30mm spacer and I'm set to go.
Allan
Reply With Quote
  #5  
Old 06-06-2013, 09:10 PM
E_ri_k (Erik)
Registered User

E_ri_k is offline
 
Join Date: Jun 2011
Location: Lakes Entrance
Posts: 809
Thanks Allan, I'll have a fiddle tonight while it's clear!
Erik
Reply With Quote
  #6  
Old 03-01-2014, 03:49 PM
pjphilli (Peter)
Registered User

pjphilli is offline
 
Join Date: Jan 2008
Location: Thornleigh Sydney
Posts: 582
Hi Erik and Others

How did your tests of the CCDT67 focal reducer go?

I am interested in getting one for my 200mm f8 GSO RC scope.

Which is the best supplier - are there any in Australia?

Cheers Peter
Reply With Quote
  #7  
Old 09-01-2014, 05:56 PM
E_ri_k (Erik)
Registered User

E_ri_k is offline
 
Join Date: Jun 2011
Location: Lakes Entrance
Posts: 809
Quote:
Originally Posted by pjphilli View Post
Hi Erik and Others

How did your tests of the CCDT67 focal reducer go?

I am interested in getting one for my 200mm f8 GSO RC scope.

Which is the best supplier - are there any in Australia?

Cheers Peter
Hi Peter. I never ended up putting enough effort into testing it because of the threads not matching into my imaging train, without an adaptor. It kind of just got put on hold because of that. I should revisit it one day, but time has been an issue

I'm not sure if there is an Australian supplier? I got mine second hand of another user.
Erik
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 09:40 PM.

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