IDAS NB2 and ODW filters are expected to come in stock next week. (NB3 will be later) Each US price is as follows;
NB2-52 : $219.00
NB3-52 : $219.00
ODW-52 : $89.00
Each is only available at 52mm. No plan for other sizes as regular round-mounted.
This is IDAS’s new filtering “system” for one-shot color cameras to maximize the nebula emission’s S/N while capturing regular RGB broadband colors without re-focusing or taking apart the optical system during imaging session.
While NB1 performs alone, NB2 and 3 requires a base filter since they don’t block NIR themselves. But don’t be disappointed. I explain why…. Following is one example.
Base filter : NGS1 is the best match with NB2 and 3. But regular UV/IR blocking filter may be used too. IDAS LPS or NGS has still good advantage if the sky is light-polluted.
For regular RGB color : ODW (as FMC full spectrum filter)
For narrow-band nabula : NB2 or NB3
And blending in post processing.
Conventional 48mm UV/IR blocking filters can be set with 52-48 stepping ring as a base filter. But be sure Hutech adapters (for M42 for APS-C or smaller and M54 for full frame cameras) are optimized for IDAS filter thickness. You need to adjust the mechanical distance when non-IDAS filters are in place.
NB2 for OIII, Ha and NII
NB3 for OIII and SII
Again, as always, each emission line is intentionally set at shorter wavelength side and the transmission peak is the flat-top shape to minimizing signal loss after the spectrum shift. Very well designed as usual.