The Baader D-ERF filter layers are designed with the utmost care. The coatings are applied with the world‘s most advanced optical coating machines, with the resultant final filters all being inspected and passed in an autocollimator on a Carl Zeiss optical bench in Germany.
To create the D-ERF filters, Baader uses a 43-layer dielectric DWDM-coating which delivers a “cool”-beam of 45nm wide pure red light around the H-alpha wavelength, towards a solar H-alpha filter system. The filter glass substrate is clear BK7 glass that is of the highest homogeneity. It is fine-optically polished to the same degree of objective-lens surfaces, and the filter has all the reflection performance coatings on one side. This reflects all the unwanted wavelengths from 280 nm up to 1500 nm, but only leaves that 45nm-wide spectral window around the H-alpha wavelength. Furthermore, these Baader Planetarium D-ERF filters are coated in a way to keep the heat load on the glass as low as possible but still ensure that it has an extremely hard, scratch-resistant coating.
Features: Baader D-ERF Energy Rejection Filter 160mm 10mm Glass
- Objective-end filter to reduce heat during H-alpha observation with SolarSpectrum Filters
- Plane parallel plate (without filter cell) with IR-Cut dielectric coating
- Filters have sealed non-aging coating edges
- Supplied as the unmounted filter only without mounting cell.
- Available in different sizes from 75mm to 180mm
Specifications: Baader D-ERF Energy Rejection Filter 160mm 10mm Glass
- TRANSMISSION RANGE 610 – 690 nm
- FILTER THICKNESS (WITHOUT CELL) 12,5 mm
- HBW (HALFBANDWIDTH) 80nm
- CWL (CENTRAL WAVELENGTH) 650 nm
- AR-COATING dielectrically coated, plane optically polished
- FILTER SIZE 75mm-180 mmFILTER SIZE 75mm-180 mm
- FILTER USAGE IR-Cut, Solar, Specialty, UV-Cut
- FILTER MOUNTED Unmounted
- TYPE OF FILTER Energy rejection
- SINGLE OR SET? Single Filter
- FILTER SHAPE round
Kit contents
Baader D-ERF Energy rejection filter 160mm (10mm glass)
User guide
