Narrow band filters increase contrast by only allowing specific light wavelengths corresponding to certain spectral lines through, e.g. hydrogen (H-a, 656nm), oxygen (OIII, 501nm), sulphur (SII, 672nm), etc. The filters can always be used for photography, even when the Moon is in the sky, or as filters for light pollution in the city. Exposure time plays no role here - long-exposure photography can also be undertaken.
Special package deal including a high-speed NBZ filter (F1.8 to F2.8) and a RASA 8 adapter.
- A filter ideally works between F1.8 and F2.8 (no signal loss by spectrum shift)
- Adapter’s light path is carefully pre-calibrated when IDAS filter is in place
- The adapter allows to orient a camera body
- Fully compatible with other IDAS Di filters (Easy filter swap)
Our expert comment:
There is very little back focus on the RASA 8. The distance is optimised for the 6.5 mm thread of some ZWO cameras.
Please note this when using the filter.
(Jan Ströher)
