IDAS NBZ-II Dualband Narrowband Nebula Filter O-III, H-Alpha - for ZWO filter drawers

IIDAS NBZ-II-DRT dual-band nebula filter also for fast telescopes and lenses

The NBZ filter is a dual line-pass filter especially for EOS cameras. It is the successor to the NBZ/NBZex filter and is suitable for all telescopes and camera lenses from f/1.9 and slower.

The NBZ filter lets the red H-alpha line and the blue-green [O III] lines pass and increases the contrast. You obtain narrow-band images with only one exposure series.

The special feature of the NBZ-II nebula filter is that it is also suitable for very fast optics up to a focal ratio of f/1.9, even with obstructed systems. This means you can use the nebula filter on practically all common telescopes and most camera lenses.

The bandwidth of 10 nm for H-alpha and 8 nm for [O III] is slightly larger for the NBZ-II than for comparable 7 nm dual-band filters from other manufacturers. This somewhat wider bandwidth has the advantage that the filter can also be used on fast optics with similar contrast without a significant loss of transmission. This means that you do not have to buy a special narrow band filter for fast systems, as the NBZ-II can be used universally. In contrast, some of the competing filters with 7 nm or narrower bandwidth reduce transmission by 50 % or more when used in a fast optical system (around f/2).

The advantages of DZ frames for filter drawers:
The Idas filters in the DZ frames are specially made for ZWO filter drawers (Gen. II). While classic 2" filters only have a clear aperture of 43 mm, the filter in the DZ frame has an impressive 47 mm clear aperture. This significantly reduces vignetting on cameras with larger sensors and telescopes with higher speed.

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