ERF-Filter
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ERF-Filters
ERF (Energy-Rejection-Filter) are essential components for solar observation. They protect the telescope and eyes from the high-energy radiation (IR heat radiation, UV radiation) and enable narrow-band filtering for observation and photography.
The Altair Dichroic Solar Energy Rejection Filter or D-ERF protects your telescope and solar imaging equipment from excessive heat build-up when solar imaging or observing with your Daystar Hydrogen Alpha Quark, or other Hydrogen Alpha Etalon filters.
595.00 €
Estimated delivery time : 1-2 days
Altair 130mm Aperture Energy Rejection filter - Ha Hydrogen Alpha only D-ERF for 5" Refractors
Product Features:
- Reduces approx. 98% of heat reaching the optics to keep Etalon from drifting off-band and protect your equipment.
- 30-40nm FHWM Bandpass at H-alpha (H) wavelength of 656.28 nm (Full Width Half Minimum) Transmission: ~90%
- UVIR blocking OD3 0.1% @400-1100nm blocking over 98% of heat to your 3rd party Etalon at eyepiece or camera end, E.g. Daystar Quark). Please note it's your responsibility to use a proper commercial Etalon with this product, and to follow the manufacturer's instructions.
- Visible light blocking: OD4 0.01% @400-700nm to reduce reflection effects and over 98% of heat.
- Diameter 140mm Thickness 12.0mm
- Multilayer coatings with SiO2 protective overcoat.
- ERF Holder cell included with soft tip threaded knobs. Tough and very light, easy to disassemble for cleaning the filter with optical wipes. Cell does not put any tension on the optics and will not scratch or damage your telescope. It also won't alter the balance as much as an aluminium cell.
799.00 €
Estimated delivery time : 2-4 weeks
The Altair Dichroic Solar Energy Rejection Filter or D-ERF protects your telescope and solar imaging equipment from excessive heat build-up when solar imaging or observing with your Daystar Hydrogen Alpha Quark, or other Hydrogen Alpha Etalon filters.
- Reduces approx. 98% of heat reaching the optics to keep Etalon from drifting off-band and protect your equipment.
- 30nm FHWM Bandpass at H-alpha (H) wavelength of 656.28 nm (Full Width Half Minimum) Transmission: ~95.5%
- 40nm FHWM Bandpass with CWL at 395nm covering Calcium H-Line and Calcium K-Line wavelengths. Transmission: ~90.5%
- UVIR blocking OD3 0.1% @400-1100nm blocking over 98% of heat to your 3rd party Etalon at eyepiece or camera end, E.g. Daystar Quark). Please note it's your responsibility to use a proper commercial Etalon with this product, and to follow the manufacturer's instructions.
- Visible light blocking: OD4 0.01% @400-700nm to reduce reflection effects and over 98% of heat.
- Diameter 140mm Thickness 12.0mm (required to achieve surface precision)
- Multilayer coatings with SiO2 protective overcoat.
- ERF Holder cell included with soft tip threaded knobs. Tough and very light, easy to disassemble for cleaning the filter with optical wipes. Cell does not put any tension on the optics.
929.00 €
Estimated delivery time : 2-4 weeks
The Altair Dichroic Solar Energy Rejection Filter or D-ERF protects your telescope and solar imaging equipment from excessive heat build-up when solar imaging ...
1359.00 €
Estimated delivery time : 1-2 weeks
The Altair Solar Energy Rejection Filter or D-ERF protects your telescope and solar imaging equipment from excessive heat build-up when solar imaging or observing with your Daystar Ha Quark, or other Etalon filters.
1739.00 €
Estimated delivery time : 2-4 weeks
The Altair Dichroic Solar Energy Rejection Filter or D-ERF protects your telescope and solar imaging equipment from excessive heat build-up when solar imaging or observing with your Daystar Hydrogen Alpha Quark, or other Hydrogen Alpha Etalon filters.
729.00 €
Estimated delivery time : 2-4 weeks
Energy protection filters are long-pass filters that block short-wave light. A coating blocks IR. This means that the filters of an H-alpha telescope are only exposed to red light.
- Diameter (mm): 100
- Thickness (mm): 12mm
- Surface shape: L/4
- Centre wavelength (nm): 656.28
- Bandwidth (nm): 60
- Peak transmittance (%): 95%
- Cut-off range (nm): 200nm-1100nm
499.00 €
Estimated delivery time : 1 week
Energy protection filters are long-pass filters that block short-wave light. A coating blocks IR. This means that the filters of an H-alpha telescope are only exposed to red light.
- Diameter (mm): 100
- Thickness (mm): 12mm
- Surface shape: L/4
- Centre wavelength (nm): 656.28
- Bandwidth (nm): 60
- Peak transmittance (%): 95%
- Cut-off range (nm): 200nm-1100nm
- with metal cell 146mm
699.00 €
Estimated delivery time : 1 week
Energy protection filters are long-pass filters that block short-wave light. A coating blocks IR. This means that the filters of an H-alpha telescope are only exposed to red light.
- Diameter (mm): 130
- Thickness (mm): 12mm
- Surface shape: L/4
- Centre wavelength (nm): 656.28
- Bandwidth (nm): 60
- Peak transmittance (%): 95%
- Cut-off range (nm): 200nm-1100nm
799.00 €
Estimated delivery time : 1 week
Energy protection filters are long-pass filters that block short-wave light. A coating blocks IR. This means that the filters of an H-alpha telescope are only exposed to red light.
- Diameter (mm): 130
- with metal cell 178mm
- Thickness (mm): 12mm
- Surface shape: L/4
- Centre wavelength (nm): 656.28
- Bandwidth (nm): 60
- Peak transmittance (%): 95%
- Cut-off range (nm): 200nm-1100nm
999.00 €
Estimated delivery time : 1 week
Energy protection filters are long-pass filters that block short-wave light. A coating blocks IR. This means that the filters of an H-alpha telescope are only exposed to red light.
- Diameter (mm): 150
- Thickness (mm): 12mm
- Surface shape: L/4
- Centre wavelength (nm): 656.28
- Bandwidth (nm): 60
- Peak transmittance (%): 95%
- Cut-off range (nm): 200nm-1100nm
999.00 €
Estimated delivery time : 1 week
Energy protection filters are long-pass filters that block short-wave light. A coating blocks IR. This means that the filters of an H-alpha telescope are only exposed to red light.
- Diameter (mm): 150
- with metal cell 230mm
- Thickness (mm): 12mm
- Surface shape: L/4
- Centre wavelength (nm): 656.28
- Bandwidth (nm): 60
- Peak transmittance (%): 95%
- Cut-off range (nm): 200nm-1100nm
1249.00 €
Estimated delivery time : 1 week
