[IDAS GNB Filter (Galaxy Nebula Booster)]
Make the subtle light of galaxies and nebulae stronger and more vivid --
IDAS's GNB (Galaxy Nebula Booster) filter has a high transmission band optimized for major emission lines such as Hα, OIII, and SII, and is a multi-narrowband filter specialized for photographing nebulae and galaxies. It effectively cuts light pollution while highlighting the fine structure and faint glow of celestial objects. It depicts the appearance of nebulae and galaxies with rich contrast, especially in urban areas and under moonlight. It is compatible with monochrome CMOS cameras and is ideal for beginners to narrowband photography.
[Features]
・Multi-narrowband design specialized for three emission lines: Hα / OIII / SII
・Powerfully cuts unnecessary visible light and artificial light
・Clearly depicts the structure of nebulae and details of galaxies
・Realizes high-contrast shooting even in light-polluted areas and moonlit nights
・Made in Japan, high-precision optical glass and durable AR coating
[Specifications]
・Screw diameter: M48mm
・Pitch: P0.75mm
・Substrate thickness: 2.0mm
・Transmission characteristics: High transmittance in each band of Hα / OIII / SII
[Recommended for]
・Those who want to clearly depict nebulae and galaxies even in urban areas
・Those trying narrowband photography for the first time
・Those using monochrome CMOS cameras
・Those who want natural emission line depiction while avoiding light pollution
Feature
The IDAS GNB filter passes through the Ha and OIII regions in the same manner as of the IDAS NBZ to suppress light pollutions in the visible light regions. Unlike any other filters available in the market, the GNB at the same time passes through the near infrared region intended for shooting galaxies that cannot be shot with any comventional nebula filters. The idea of designing this filter is based on the fact that the near infrared region can be hardly affected by artifical light pollution sources.
Notes:
We recommend the use with a NIR-enhanced sensor such as IMX585 and IMX464 especially where the GNB is used in a heavly light-polluted location.
The GNB filter will enhance the colorfulness of galaxies when used with a conventional sensor (such as IMX294).
n.b. on halos:
Optical filters such as IDAS GNB and DTD utilizing infrared tend to cause haloing in the NUV and NIR regions. This is because the anti-reflection properties of off-the-shelf cameras' optical systems (oiptical window and sensor cover glass) are optimized for the visible spectrum only, not for the NIR region. Thus, haoling at the camera end in the unoptimized region becomes more apparent, coupled with haloing from the filter itself.
Here is a rough estimation of the magnitude of haoling where the haloing maginute of NBZ (NBZex) is counted as 1:
GNB + IMX294 sensor results in 8.0 times
GNB + IMX585 sensor results in 6.3 times
| *This product is an interference filter. Its spectrum characteristics will be subject to the incidence of incoming light. |
| When the GNB filter is placed between the lens and the camera: |
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