Orion Extra-Narrowband Tri-color CCD Imaging Filter Set.

Shoot high-contrast color CCD images of emission nebulas from light polluted or moonlit
skies.
Set consists of three dichroic, 1.25" extra-narrowband imaging filters: H-alpha, O-III, and S-II
These filters transmit specific wavelengths emitted by emission nebulas; block all other light.
Each filter has 90#&37; transmission at the critical wavelength and a narrow 7nm bandpass
(FWHM).
Ideal for use with the StarShoot Deep Space CCD Monochrome Imager and Manual 5-Filter
Wheel.
Filters are parfocal with each other.


Imaging with extra-narrowband filters is the latest technique used by amateur astronomers for
producing striking, high-contrast color CCD astrophotos of emission nebulas. And it works
even in heavily light polluted or moonlit skies.

What you need is this three-filter set, which consists of Orion Hydrogen-alpha (#5587),
Oxygen-III (#5578), and Sulfur-II (#5579) extra-narrowband imaging filters (1.25"). These
specialized "line" filters transmit only the specific wavelengths of light important in emission
nebulas, while blocking out all the rest. The filters are designed for use with the Orion
StarShoot Deep Space CCD Monochrome Imager II (#52083) and Manual 5-Filter Wheel
(#5520), or with similar cameras.

The H-alpha filter has a transmission of 90% at the hydrogen-alpha line of 656.3nm and a full
width at half-maximum (FWHM) bandpass of 7nm. The O-III filter passes light at the 500.7nm
wavelength (the Oxygen-III line) with very high 90% transmission and a bandpass of 7nm. And
the S-II filter passes light at the 672.4nm wavelength (the Sulfur-II line in the deep red end of
the visual spectrum) with 90% transmission and a bandpass also of 7nm.

Images taken with extra-narrowband filters typically look different from those acquired using
standard "true color" (RGB) methods. Rather than rendering an image in its "natural" color,
the extra-narrowband filters provide a visual representation of the elemental makeup of a
nebula, highlighting with assigned colors the areas where the light derives predominantly from
either S-II, O-III, or H-alpha ions. This is the approach used by astronomers for many of the
nebula pictures taken with the Hubble Space Telescope. The extra-narrowband tri-color
images, while beautiful, also reveal much about the chemical composition of the nebula and
its various features.

These 1.25" filters are made from high-grade glass and feature vacuum-deposited dichroic
interference coatings and antireflection coatings. Each filter is held in an anodized aluminum
cell that is threaded to fit a standard CCD camera 1.25"? nosepiece or the Orion Multiple
Filter Wheel. All three filters are parfocal with each other, so refocusing is not needed when
switching between filters in the set.

So if you're ready to go beyond RGB imaging and capture your favorite nebulas in a revealing
new light — no matter how light-polluted your skies — add our Extra-Narrowband CCD
Imaging Filter Set to your imaging repertoire! Includes a protective plastic case for each filter.

Price - £259.00

The Astronomy Shop

1 Tone Hill. Wellington

Somerset TA21 0AU

United Kingdom

Telephone: +44 (0)1823 665510