The Lumicon 2" Thread-In Focal Reducer is a diverse problem solver, widening the fields and reducing the exposure times wherever and however it is used.
On the front it has a 2" outer diameter, and on the rear it has 48mm male filter threads. You can screw this in to the bottom of a 2" eyepiece just like a filter for a mild focal length reduction, but you can also screw this on to a 2" diagonal's filter threads for a more pronounced reduction.
For prime focus SLR imaging without an eyepiece in the optical path, thread this focal reducer in to Lumicon's LA1080 2" Male to T-Mount Male Adapter for a mild focal reduction, or to the #LC1025 2" Prime Focus Camera Adapter for the strongest focal reduction.
Fully multicoated 200mm focal-length achromatic lens
Can be used with Lumicon's 2" Newtonian/Refractor Easy Guider on refractors and longer focal-length Newtonians (>= f/10)
Threads into Lumicon's 2" Prime Focus Adapter (LC1025) for substantial photographic reduction
Threads into Lumicon's 2" Male to T-Thread Male Adapter (LA1080) for slight photographic reduction
Can be threaded as a filter to 2" eyepieces and diagonals