TS Optics helical focuser 1.25″ (M54)
Looking for a way to achieve truly fine and stable focusing with your telescope or optical setup? The TS Optics helical focuser with M54 thread is exactly what you need. This compact micro-focuser with a calibrated scale brings the level of precision you expect from high-quality photographic lenses - directly into your telescope system.
Smooth, non-rotating focusing movement
The focuser connects to the telescope side via an external M54x0.75 thread (threaded section length 5 mm), fitting all adapters and focusers that feature a standard internal M54x0.75 thread on the eyepiece side. The helical mechanism provides smooth, non-rotating travel of the optical path - the lens or camera does not rotate during focusing, which is a real advantage for imaging and precise visual observation alike.
Dual output: T2 and 1.25″
On the output side you have both an external T2 thread (M42x0.75) and a classic 1.25″ barrel, so you can attach an eyepiece, projection adapter, or camera without any compromise. The combination of T2 thread and 1.25″ barrel ensures maximum flexibility and compatibility with a wide range of accessories.
Reproducible focus position
The 11 mm focusing range together with the calibrated scale allows reproducible settings - once you find the ideal focus position for a given eyepiece and telescope combination, you can easily return to it. When the correct focus is reached, the position is locked securely with a knurled locking screw that reliably prevents any unwanted shift. This is invaluable especially during long-exposure imaging or when switching between eyepieces during an observing session.
Technical specifications
| Parameter |
Value |
| Input thread (telescope side) |
M54x0.75 external (threaded section 5 mm) |
| Output - thread |
T2 / M42x0.75 external |
| Output - barrel |
1.25″ |
| Focusing range |
11 mm |
| Minimum total length |
74.5 mm |
| Focusing mechanism |
Helical, non-rotating |
| Locking |
Knurled locking screw |
| Scale |
Calibrated focusing scale |
Who is this focuser for?
The minimum total length of 74.5 mm is an important parameter when calculating the optical path of your setup - whether you are building a system for visual observation, planetary imaging, or deep-sky astrophotography with a projection adapter.
The TS Optics helical focuser 1.25″ (M54) is an elegant and practical solution for anyone who wants full control over focusing - without unnecessary complexity, but with sufficient technical precision for serious astronomical and photographic use.
