Holds up to 5-1.25" type filters. The filter selector contains a red, IR, broadband, and narrow band filter and is only used
with the Cookbook camera. This selector is useful in having a variety of filters available for quick selection.
Light Pollution Filters - SkyGlow broadband and narrowband
Light pollution compromises deep-sky performance by washing out stars, faint nebulae, and galaxies. These filters block
all of the urban light pollution I've encountered. They selectively reject the undesirable light from street glare, airglow,
backyard lights, neon lights, blue-white of the mercury vapor lamps, as well as the pink and yellow of high and low pressure
sodium vapor lamps. The superior gain in contrast between the objects that are being viewed and the black sky allows you
to view galaxies, nebulae, star clusteris, and comets like you've never seen before! It's a must for any light polluted sky.
The broadband filter passes desirable wavelengths such as hydrogen-beta and oxygen III, and hydrogen-alpha.
Most of the time, this filter is in use with the eyepiece and the cameras. It is best suited for viewing galaxies and star clusters,
because most of their light covers the visible spectrum. A 2" Lumicon filter is used with the starlight HX916.
The narrowband filter passes the three most important visible wavelengths emitted by deep-sky emission nebulae.
Spectral lines of hydrogen-beta at (486nm) and Oxygen III at (496nm and 501nm). Plus Hydrogen Alpha. Virtually all
unwanted light emissions are rejected by factors of 99.9+%. The filter improves visible contrast and detail on fewer
objects and requires longer CCD exposures. It's not used with the Starlight Xpress MX5-C color camera.
Near-Infrared Continuum Filter - Murnaghan IR-C-Cell-1.25
Transmits100% of the entire infrared band. Completely blocks ultraviolet light and most visible light. Transmittance of light
begins in the deep red 700nm and continues to the CCD's detection limit. Infrared light is beyond the sensitivity of our eyes
and most photographic film, but the Cookbook CCD has a 30%-40% overall response. Near-infrared light can pass
thru nebula dust clouds, and CCDs can reveal the buried stars.
IRX Infrared Exclusion Filters - Murnaghan IRX-Cell-1.25
This filter eliminates infrared light where it counts the most, from 690nm to >1100nm. Visible light is transmitted with high
efficiency. Used with Starlight Xpress MX5-C to preserve chromatic accuracy, help colour balance and colour rendering.
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Copyright © 2010 Calvin Hill