When would I need the Baader 1.25" Nosepiece Extension?
You need this extension when you cannot achieve focus because your eyepiece needs to be positioned further away from the telescope. This is a common issue when adding accessories like off-axis guiders, flip mirrors, or certain Barlow lenses that extend the light path.
How does the Baader Nosepiece Extension attach to my eyepiece?
It attaches directly to your eyepiece. Simply screw the male-threaded end of the 18mm extension into the female 1.25" filter threads found on the bottom of almost every standard 1.25" eyepiece barrel.
Can I still use my 1.25" filters with the Baader Extension in place?
Yes. The extension is designed with female 1.25" filter threads on the telescope side. This allows you to screw any standard 1.25" filter directly onto the end of the extension, placing it in the light path just as it would be if threaded into the eyepiece itself.
My off-axis guider pushes my eyepiece too far out to focus in my SCT. Will the 18mm Baader Extension help?
Yes, this is the exact scenario the Baader 18mm Extension is designed for. By adding 18mm of length, it compensates for the extra distance introduced by the off-axis guider's prism, allowing you to rack your SCT's focuser inward to a point where a sharp image can be achieved.
Will the Baader 1.25" Extension introduce any vignetting?
For most eyepieces, no. The internal diameter is designed to be as wide as possible. However, with very long focal length 1.25" eyepieces (like a 40mm Plössl) used in very fast telescopes (f/4 or below), any extension can potentially cause minor vignetting at the edge of the field of view.
I can't reach focus with my new flip mirror and a Tele Vue Plössl. Is the Baader 18mm extension the right solution?
Yes, it is very likely the correct solution. A flip mirror adds significant length to the optical path, which requires the eyepiece to be moved further out. The Baader 18mm extension provides that needed distance, allowing the Tele Vue Plössl to reach the new focal plane.
