6 replies to this topic

[25585]

Can anyone recommend small 1.25" helical focusers, to make small adjustment for each eye as IF binoculars have?

[Andrea Salati]

If an M42 connection on the telescope side is acceptable, there is a very cheap one available from SvBony and other sources in China.
I used one for a while and it got the job done well enough for me. See picture.

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[Enyo]

I have found that just sliding one of the eyepieces up in the holder works very well. Only need to do that when I am using a filter in one eyepiece and none in the other.

[balcon3]

Be aware that some of the cheaper helical focusers rotate the eyepiece, which can cause distortions. I use a ZWO helical focuser on my Mewlon 180c for micro focusing and it is very smooth. But I put this between the diagonal and the binoviewer, so it is not used for individual eye adjustment.

 

https://www.teleskop...ng-system-11481

 

Adding a helical focuser will increase the path length which may affect your ability to reach focus, which is often an issue with binoviewers.

 

I'm not sure how one would connect a helical focuser after the binoviewer, since there will be just a 1.25 inch eyepiece hole. How will you attach the helical focuser?

[Feds27]

Baader makes one.

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[denis0007dl]

Best one!

[arg0s]

A recommendation I've seen for the Heritage line of telescopes is YZ-18839. It's like the Svbony focuser, but the input and output are both 1.25", so no threading required. Never used it myself though.

Edited by arg0s, 22 March 2025 - 04:27 PM.