IDAS NB2 dual band narrow band fog filter O-III, H-Alpha 2" mounted

The nebula filter allows O-III and H-Alpha to pass through and ensures a particularly high contrast; it was developed for astrophotography.
 
 The filter is delivered in a 2" filter holder (M48x0.75) and fits into appropriate adapters, filter drawers or filter wheels
 Dual filter with passage in O-III and H-Alpha
 The filter is particularly suitable for recording planetary nebulae and diffuse gas nebulae
 Scattered light and nightglow are effectively suppressed, while the stars and sky background are left relatively neutral
 High-quality anti-reflective coating thanks to an anti-reflective layer
 Scratch-resistant hard coating
 With a thickness of 2.5 mm, the filter is parfocal to other IDAS filters
 IDAS fog filters are produced in Japan

 
IDAS NB filters from Hutech have been specially developed for astrophotography
The NB2 filter is a dual line pass filter that can be used with one-shot color cameras (OSC) such as DSLRs, mirrorless system cameras or astronomical cameras.

The NB2 filter passes the red H-alpha line and the blue-green OIII lines and increases the contrast. You get narrowband images with just one series of exposures. The resulting images can be used to improve the contrast of traditional RGB images or to create images in various popular false color palettes.

The NB2 nebula filter does not block near infrared light. An IR cut filter is therefore recommended.

The most important features of the IDAS NB2 fog filter:
 Allows an exposure extension of approximately 4 times
 Allows O-III and H-alpha to pass through
 Passing areas are slightly broadened towards larger wavelengths in order to allow the lines to pass through large angles when the light falls at an angle, making the filter also suitable for very bright optics
 Suitability for narrowband imaging of diffuse emission nebulae and planetary nebulae
 High-quality anti-reflective coating - anti-reflective layer
 Particularly scratch-resistant hard coating
 Absorption of urban scattered light (mercury, sodium vapor lamps...) and nightglow

Exposure time extension - factor 4:
The IDAS NB2 allows the exposure time to be extended by a factor of 4. However, the most important lines in the deep sky area (H-alpha and O-III) are transmitted by 90%.

To put it simply, you can expose about four times as long until the sky background comes through, but the object appears significantly stronger and more contrasty against the background than without a filter.

Difference NB1 - NB2 - NB3 - NBZ fog filter:
All three filters are suitable for color and mono cameras, DSLRs and system cameras. A combination of these three filters enables extreme narrowband recordings with mono and color cameras.
 NB1: Triple filter with pass in H-Beta, O-III and H-Alpha. The filter also blocks nearby IR light; you don't need an additional IR blocking filter. The NB1 is the most versatile filter. We also recommend the filter for astro-modified DSLRs and system cameras.
 NB2: Dual band filter with pass in O-III and H-Alpha. The contrast effect is very strong. The filter is well suited for color astro cameras with a built-in IR cut filter and for photography with pure reflecting telescopes without a corrector, such as RC telescopes.
 NB3: Dual band filter with pass in O-III and S-II. The contrast effect is very strong. This filter is ideal for photographing objects that emit light in the S-II (sulphur/sulfur) range. These nebulae often still have an O-III component.
 NBZ: Dual band filter with very narrow pass of 5-6nm (ultra narrow band) in O-III and H-Alpha for extreme contrast.

Socket: 2" socket - M48x0.75
Technology: interference filter
Filter glass thickness: 2.5 mm +/- 0.1 mm

 IDAS fog filter