Antlia 2 inch quad band nebula filter for galaxies, nebulae, star clusters - No HALO problem

Antlia Quad Band Anti-Light Pollution Filter - 2" Mounted

The Antlia Quad Band Anti-Light Pollution Filter is a nebula filter for color and monochrome cameras. The filter offers a significant increase in contrast for all common deep-sky objects such as galaxies, reflection nebulae, emission nebulae and star clusters under a sky from Bortle 8 to Bortle 1. The spectral transmission covers the visible light range, the near ultraviolet (NUV) and the near infrared (NIR) range. The areas of artificial lighting, on the other hand, are blocked out. This means that the filter can be used near cities as well as in the mountains.

Is the Antlia Quad Band a broadband or narrowband filter?
The filter is both, it is narrower band than a typical broadband filter and therefore offers significantly better contrast and allows longer exposure times. However, at 25-30 nm, it is wider than typical narrow-band filters, which are between 5 nm and 15 nm. In our opinion, the Antlia Quad-Band is both, it closes the gap and allows high-contrast images of objects. The filter is particularly exciting for objects that combine different light components, such as an emission nebula in which reflection components are embedded and possibly also [O III] regions. Galaxies, which contain all light components, are also displayed with particularly high contrast with this filter and can also be photographed from close to the city.

The Antlia Quad Band is suitable for almost all telescopes and objectives.
The Antlia Quad-Band filter has a wide passband which is designed for faster optics up to a focal ratio of f/2. This means that the filter can be combined with very fast camera lenses as well as with a refractor or Newtonian, which usually have a focal ratio between f/4 and f/7. Even with slower systems such as RC or EHD telescopes, which have between f/8 and f/10, an improvement in results can be achieved with the filter, as valuable object light is hardly wasted. The filter also has a passband in the near IR, which is particularly important for galaxies. The far IR, on the other hand, is blocked out, as most refractors or correctors are not well corrected in this range. The Quad-Band therefore also fulfills the function of an IR blocking filter.

Main features and application:

Anti-light pollution - the Antlia quad-band filter is an effective solution for reducing light pollution as it blocks out most of the 589 nm orange-yellow light and some of the blue light from LEDs.

Over 95% of deep sky objects can be captured - not only gas nebulae and planetary nebulae, but also reflection nebulae and galaxies.

The high transmission of the most important emission lines improves contrast and also allows the use of fainter telescopes

The transmission for the near infrared range is intended for capturing deep-sky objects that cannot be captured well with other filters without NIR transmission.

The wide pass band between 25-30 nm is designed to be compatible with faster optics up to focal ratio f/2.

Very good color balance, especially because blue components are also included. Not only nebulae, but also star colors become more natural.

Surface Quality: S/D (scratch/dig)= 60/40 (refer to MIL-O-13830)

Transmitted wavefront: Lambda/4 or better.

Parallelism: less than 30 arc seconds

Warranty: 3 years against coating delamination