Orpington Astronomical Society

Astronomy => Telescopes Etcetera.... => Topic started by: Kenny on Jun 21, 2014, 18:14:12

Title: Eyepiece threads
Post by: Kenny on Jun 21, 2014, 18:14:12
Interested in others advice/experience.

Bought a set of moon/planetary filters from Astronomia but they only fit some of my eyepieces.
- Filters don't fit the 25mm and 6.5mm eyepieces that came with my cheap "Event Horizon" scope I bought on ebay years ago but I didn't expect them to. It's a cheap Chinese knockoff. Both eyepieces have a thicker thread that only fits the rubbish moon filter that came with the scope.
- Filters do fit the unbranded 40mm, 32mm and 10mm Plossls I was given with my Orion dob, I think they were purchased separately from the dob.
- Filters partially fit (won't fully screw on) the 25mm, 9mm Orion-branded Plossls that were purchased with the Orion dob. This is the biggest surprise for me, that the Orion eyepieces don't have a standardised thread that fully fits the filters.

Do all eyepieces these days have a standardised thread? ie if I bought more the filters would fit?

My Orion Skyquest dob is probably at least 10-15 years old. Could that be the issue? ie threads weren't standard at the time of manufacture?

Title: Re: Eyepiece threads
Post by: mickw on Jun 21, 2014, 19:00:40
QuoteDo all eyepieces these days have a standardised thread? ie if I bought more the filters would fit?

Nope

The threads are a total shambles, a mix of imperial an metric threads which are never explained when you make your purchase.

You will have fun trying to get it sorted  :-?


Oops sorry, was thinking of something entirely different   :oops:
Title: Re: Eyepiece threads
Post by: The Thing on Jun 21, 2014, 21:59:26
All my 1.25 and 2 inch filters fit all the appropriate eyepieces. They have a standard thread. They come from a wide selection of sources.