The NBZ is a dual band nebular booster filter that transfers OIII and H-alpha emission lines with the band width of 12nm (+/-0.4nm) at each band. Halos that occurred around the ojbects with the predecesor "NBX" filter can now be decreased 1/100th thanks to the technology we have developed to surpress the repetitive reflections of the filter itself..

Feature 1
You may have already noticed that the half value band width (12nm) of the NBZ is a little wider than that of competitive narrow band filters claiming the half value band width of 7nm. It should be noted, however, that this wider band width has a great advantage.
The transmittance curve of interference filters will naturally shift towards the shorter wave length side against oblique light incidence, and this tendency will be more noticeable as the inncidence angle becomes higher as shown in the following figure.
Some of the competitive 7nm filters will decrease in transmittance by 50% or more when used after the fast optical system (around F2), while the NBZ retains 80% or more of the transmittance under the same conditions. This means that you can shorten the exposure time to 2/3 to a half (and moreover you can gain the same or better contrast) with the use of the NBZ when compared with the competitive 7nm filters.



Feature 2
The NBZ filter utilizes the IGAD (ion-Gun AssistDeposition) coating technology which has been applied to our regular LPS-P2 and LPS-V4 series. The IGAD technology densifies the multi-layers - the heart of interference filters - resulting in the physical properties that cannot be obtained from the conventional multi-layers.
1) Highly durable thin layers of which hardness equals to quartz glasses. Tremendously improved adherence between the substrate and the multi-layers set.
2) Absolutely almost no aging variation in optical spectral characteristics due to temperature and humidity change as far as used in the regular human living environments.