|Lentilles de Barlow / Barlow Lenses |
POWERMATE 2" 4x
The Powermate consists of a negative doublet plus a positive “pupil-correcting” doublet. This 4-element system provides the magnifying function of a Barlow without its limitations by restoring the field rays back to their original direction, as if the Powermate were not there. The result is a pure magnification increase.
Vignetting, edge field aberrations and pupil movement - all introduced when using Barlows with long focal length eyepieces, are minimized.
Telecentric operation (field rays leave parallel to optical axis, unlike Barlow lenses which diverge rays).
This is ideal for Hydrogen-alpha filter use such as with Daystar models.
High performance for image amplification, CCD or film.
Flexible for visual and imaging with all types of telescopes and eyepieces. Essentially Parfocal, and with nearly constant magnification regardless of image distance behind top surface (except 5x model which increases 1x for every 35mm of image distance increase).
Higher magnifications are possible with high optical performance compared to “doubling up” Barlows.
All will reach parfocal point in star diagonals, except for the 2”, 2x which comes very close.