NB1 Filter Bandpass Plot -- Click to enlarge
IDAS NB Filters are designed to enhance the contrast of emission nebula, yet accommodate the filter
spectral shift* when used with modern fast optical systems.
Features include:
- Ideal flat-top and moderate bandpass
- Excellent in-band transmission
- Extremely steep bandpass edges minimize internal reflections
- Near IR (NIR) is blocked up to 1100nm
- Available in 52mm and 48mm sizes
- 2.5mm thickness (parfocal with other IDAS LPS filters)
- IDAS-proprietary IGAD/MBT/UFP quality
- Made in Japan
*
All interference filters are subject to a bandpass spectral shift which depends on the angle of incidence
of the incoming light. IDAS NB filters are designed to accommodate the spectral shift of modern fast
optical systems.
When placed in front of an optical system, the spectral shift is determined by the focal length of the
optics and the size of the imaging sensor. For an APS-C sensor, up to a 50mm focal length can be
accommodated. For a full-frame sized sensor, up to an 80mm focal length can be used.
For filters placed between the optical system and imaging sensor, the situation is more complex. IDAS NB
filters are designed with modern fast optics in mind and can accommodate an angle of incidence of up to
14°.
NB Filter Types:
|
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.
Example images in the Hubble Palette synthesized with images
shot through IDAS NB2 and NB3 filters, by William Shaw (UK).
|
