Celestron Zoom eyepiece T-threads - adapter?

[Peter_D]

Hi,

Firstly, sorry for the rather basic question. 

I have a Celestron 1.25 inch 7-21mm zoom that I just discovered has external threads! I have a Canon t-ring and dslr -  I'm just not sure which adapter goes between the zoom eyepiece and t-ring/camera. (I don't want to make a mistake ordering the wrong part.)

Any guidance gratefully received!

Peter

PS: I see that you can buy Barlow lenses with these external t-threads also. Presumably the same adapter will work on these too?

Peter

[Cornelius Varley]

Have you measured the diameter of the threaded part ? The thread on the Celestron barlow is compatible with the t-thread on your t-ring (M42x0.75mm)

[Cornelius Varley]

PS. Just measured my old AE 7-21 zoom (I think the same) and this has the same thread. Astroboot has the AE adapter ring (AC721) which fits the SW 7-21 zoom.

[AlexAntao]

Sorry to raise this old topic, but I found it because I have the same problem here. 

Have a CElestron 7-21mm eyepiece and a T-Ting for my NIkon. I'm Almost shure the T-Ring has M42 internal thread, I think the pitch is 0.75mm, but I'm not shure. I'll try to include pictures.

Eyepiece hass about 37mm thread, so I think it 's M37...  but i know there's the question about the pitch of the thread... 

Did you found a solution ???

 

Edited September 2, 2022 by AlexAntao

[Louis D]

What about a simple 42mm to 37mm step down ring?  Have you tried that yet?  A T-mount thread is simply M42 (42mm x 0.75mm tp).  Here's the same link on ebay UK.

[AlexAntao]

2 hours ago, Louis D said:

What about a simple 42mm to 37mm step down ring?  Have you tried that yet?  A T-mount thread is simply M42 (42mm x 0.75mm tp).  Here's the same link on ebay UK.

Thank you !!!! I was looking for it a whole day and found almost nothing....