NB1 Filter Bandpass Plot -- Click to enlarge

The NB1 filter is a triple line-pass filter which can be used with one-shot color (OSC) cameras such as DSLR's or astronomical OSC cameras.

Passing the red Hα+NII and the green-blue Hβ+OIII lines, the NB1 filter enhances the contrast of emission line nebulae without the time-consuming use of single-band filters.

More on other members of the NB filter family...
 

	Emission Lines	Filter Sizes	Base Filter
NB1	Triple - Hβ+OIII, Hα	48mm & 52mm	None required
NB2	Dual - OIII, Hα	48mm, 52mm, Canon Drop-in	Required*
NB3	Dual - OIII, SII	48mm, 52mm, Canon Drop-in	Required*

  * In-camera IR blocker works as the base filter.