The Fringe Killer filters is designed for use with
not-corrected achromatic refracting telescopes to perform well into the
violet and deep red portions of the spectrum. It is a multi-bandpass
filters transmitting most light in the visual spectrum while attenuating
much of the light in the violet portion of the spectrum. It also blocks
light in the infrared region for CCD imaging, doing all of this while
passing a high percentage of the critical yellow green portions of the
visual spectrum. The Fringe Killer rejects almost all below wavelengths
of 420nm - in the violet portion of the spectrum, while blue light from
420 nm to about 480 nm is attenuated by about fifty percent. The filters
enhances contrast, making the objects appear sharper and more clear
particularly when observing the brightest objects like the moon, planets
and very bright stars. This filters is not at all necessary for use with
reflecting or well made apochromatic telescopes. Nor is it beneficial
for visual uses with the faint extended objects (nebulae, etc.). Plasma
assisted, hardest, scratch proof and water impermeable dielectric
coatings of almost 50 coating layers on either side pertains to the
carefully designed to extend equal tension onto either side of the
substrate. The ion beam deposited coatings on both surfaces are durable
and scratch resistant. They will not degrade over time. When combine
with Nemodymium Moon & Skyglow filter provides breathtaking contrast on
lunar and planetary surface detail. The 31.7mm / 50.8mm sized filters
will thread into conventional slip fit eyepieces or accessories with the
common 1.25" / 2.0" inch threading respectively. |