2" Filter with 1.25" EPs

[chbrandt]

I recently purchased a 2" NPB filter from DGM Optics and am having some trouble using it with my 1.25" EPs.  I have an adapter to go from 2>1.25 with filter threads but the problem is my EPs go just a tad too far through the adapter to the point that I think they would hit my filter if it was threaded on.  I don't want to attempt to just not totally thread the adapter on, nor do I want to tighten the screw on the EP when it's not all the way in to keep it from touching.  I'm thinking I either need an adapter that has more room or maybe some kind of male to female adapter to screw into the adapter to add more room.  I've looked some but can't find exactly what I need.  Any ideas?  Thanks!

Chris

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Orion SkyQuest XT8 Dobsonian with TelRad. Eyepieces: 30mm Explore Scientific 82° (40x, 2.05°), 14mm Explore Scientific 82° (86x, 0.96°), 8.8mm Explore Scientific 82° (136x, 0.60°). Celestron SkyMaster Giant 15x70 Binoculars on 70" Pistol Grip Tripod

[John]

Hi Chris,

I use a 14mm Baader Fine Tuning ring on the end of my 1.25" - 2" adapter:

http://www.optcorp.com/telescope-accessories/optical-tube-accessories/eyepiece-diagonal-accessories/baader-14mm-fine-tuning-ring-hyperion-hdft-14.html

These things screw into the 2" filter thead at one end and are threaded themselves for 2" filters at the other. The FT ring moves the filter far enough away from the bottom of the adapter to ensure that it clears any 1.25" eyepiece barrels inserted into it.

[chbrandt]

Perfect, exactly what I needed!  Thanks John!

[chbrandt]

John--

I have been reading a bit about these and just wondered how they would change the FL and magnification of my EPs?  I currently use an 8.8mm and 14mm, both in my 1200 FL scope, and plan to eventually purchase a 6.7mm to round out my set.  Will this ring significantly change my magnification when using filters?

Chris

[Stu]

John--

I have been reading a bit about these and just wondered how they would change the FL and magnification of my EPs? I currently use an 8.8mm and 14mm, both in my 1200 FL scope, and plan to eventually purchase a 6.7mm to round out my set. Will this ring significantly change my magnification when using filters?

Chris

Chris, the ring should not affect the focal length of the eyepiece at all if put in front of the diagonal. That is assuming you are using a refractor (EDIT or a newt.) With an SCT it may have a small impact (increase), but nothing major I don't think.

[John]

John--

I have been reading a bit about these and just wondered how they would change the FL and magnification of my EPs?  I currently use an 8.8mm and 14mm, both in my 1200 FL scope, and plan to eventually purchase a 6.7mm to round out my set.  Will this ring significantly change my magnification when using filters?

Chris

There are no optics in the ring Chris and the filter doesnt have any amplifying effect. If won't affect the magnfication at all with your scope.

[Moonshane]

As suggested by John http://stargazerslounge.com/topic/84086-novel-use-for-baader-fine-tuning-rings/

[John]

As suggested by John http://stargazerslounge.com/topic/84086-novel-use-for-baader-fine-tuning-rings/

Gosh, where did those 5 years go ......

[Moonshane]

wow, I know! I still have the same set up too. Well, the FTR and adapter at least