Lumicon 2.5x CCD Compressor Lens

The Lumicon 2.5x CCD Compressor Lens threads into the nosepiece of 1.25" CCD imagers, widening their field of view when imaging with refractor or catadioptric telescopes.

In its standard configuration (~1.20" nosepiece-to-chip distance), it yields a 0.4x reduction.  A 1000mm focal-length telescope would effectively become a 400mm focal-length system.