A filter for enchanced H-alpha nebula observations with UV/near IR suppressiong function - especially removing red end spectrum interference.
The HEUIB-II is a UV/IR-cut filter enhanced for shooting H-alpha nebulae at wave length of 656.3nm.
This will reduce the interference from the red end spectrum associated with regular astronomical IR-cut filters such as UIBAR-III, and as a result enhance the wave length of H-alpha nebulae. Even in comparison with our conventional HEUIB filter, HEUIB-II has less interference from the red end spectrum as a result of the increase in the red spectrum suppression range. Thus, the image of nebulae at the H-alpha region will get enhanced.
The HEUIB-II 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.
