Astrodymium Rotating Tilt Adjusters for M42, M48, and M54 Threads

Description

Purchase this product from AgenaAstro or First Light Optics.
These rotating tilt adjusters compensate for tilt in your imaging train when using any threaded adapter or extension tube. The adapter only needs to be partially unthreaded to allow the tilter to rotate to the area that needs to be compensated for.
The M42 size in particular is designed for use with ZWO's EOS/Nikon adapters, but it will also work with any M42 thread.
Note:
Each tilt adjuster adds 0.40mm
± 0.02
of backfocus.
Each set comes with 3 levels of adjustment: 0.1, 0.2, and 0.3mm, and the corresponding amount is debossed onto the adjuster itself with roman numerals.
I = 0.1mm
II = 0.2mm
III = 0.3mm
How does it work?
A raised section on each adjuster acts as a shim, which pushes one side of a threaded adapter higher than the other, this is the mechanism that creates the tilt effect.
The maximum amount of compensation that can be produced is dependent on the tolerance of the threads (how much slop they have).
For example, ZWO's extension tubes (16.5 & 21mm) have been tested to produce a maximum of 0.20mm worth of tilt.