Baader C2 Swan-Band Filter 15nm 2 inch

Baader C2 Swan-Band Filter 15nm 2 inch: gain in contrast for comet hunters

Comets with an active gas tail shine primarily in the two C2 carbon lines at 511 and 514 nm, the so-called Swan bands. This filter transmits precisely those two lines and blocks almost all other light, including the nearby OIII line at 501 nm. The result: a comet's gas tail and coma stand out against a dark sky background.

While other Swan-band filters partially transmit the OIII line, this Baader filter blocks it completely. This allows you to immediately see the difference between a gas tail and a dust tail, and also makes the filter useful as an OIII parallel reference filter.

Built on Baader's CMOS filter technology

The filter is CMOS-optimized with Reflex-Blocker hard coating against halos, plano-optically polished glass, blackened edges, and Life-Coat edge sealing for a lifetime coating.

Visual and photographic

Visually, the gas tail of a bright comet clearly gains contrast. Photographically, you isolate the C2 emission for images that show the structure of the tail, even under a light-polluted sky.

Featured accessories

For deep-sky nebulae besides comets, the Baader Narrowband OIII and H-alpha filters are the logical addition.

For whom yes and for whom no

• ✓ Comet hunters, visual and photographic
• ✓ Observers who want to distinguish gas and dust tails
• ✗ Anyone who primarily photographs emission nebulae: choose an OIII or H-alpha filter

Specifications

You can find more accessories for this brand at the Baader brand page.