Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Polarizing filter setup with f/5 Hardin 10"

reflector observing moon equipment dob
  • Please log in to reply
2 replies to this topic

#1 kev8star8

kev8star8

    Lift Off

  • *****
  • topic starter
  • Posts: 1
  • Joined: 25 Nov 2014

Posted 06 August 2019 - 08:34 PM

Hello,

How can I determine the amount of focus travel (not sure the correct term if it is inward or outward focus) before I can no longer focus.

I have a 2" polarizing filter to use in a standard rack and pinion. I need to purchase an extension tube to attach one filter and need to know the mm I can use.

 

Thanks,

Kevin

 

254mm (10")

1250mm

f/4.9



#2 Barlowbill

Barlowbill

    Viking 1

  • *****
  • Posts: 520
  • Joined: 05 Apr 2018
  • Loc: Tulsa, Oklahoma

Posted 06 August 2019 - 09:17 PM

All I can tell you is my Orion 2" Polarizing filter extends 5/8" below the threads.



#3 Greyhaven

Greyhaven

    Skylab

  • *****
  • Posts: 4491
  • Joined: 11 May 2004

Posted 08 August 2019 - 12:31 PM

The 10" Hardin came with a 2" focuser and 1.25 reducer doesn't your  Orion 2" Polarizing filter thread into your 2" EP I don't see an issue. Unless you don't have the 2" EP that usually came with the scope, if that's the issue just order the Orion 1.25 Polarizing filter you really need.

Grey




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: reflector, observing, moon, equipment, dob



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics