Optolong L-eXtreme F2 Dual Narrowband OIII (7nm) & H-a (7nm) Highspeed Filter for f/2 - f/3.3 Telescopes - 1.25" Mounted
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Optolong L-eXtreme F2 Overview
The Optolong L-eXtreme F2 is a dual-band (500.7 nm and 656.28 nm, FWHM=7 nm) narrowband pass filter that meets the transmission requirements for fast optical systems that have a steep light angle. The transmission wavelengths of the OIII and H-Alpha nebula emission lines pass accurately between f/2 - f/3.3 focal ratios. Optolong has developed this filter specifically for fast focal ratio imaging systems. It has performed well on RASA, HyperStar and other fast focal ratio telescopes.
Key Features
- Ideal for monochrome or one-shot color CMOS cameras as well as digital SLR and mirrorless cameras.
- Quickly obtain clear and detailed images of deep sky nebulae.
- Ideal for fast optical systems, like RASA, Hyperstar and other fast focal ratio telescopes.
- Recommended for use with fast optical systems with a focal ratio between f/2 to f/3.3.
- Cuts through light pollution offering better contrast and more detail in emission nebulas.
Spectrum and Characteristics
- Substrate: Optical glass
- Size: 1.25" mounted (M28.5x0.6 male)
- Thickness: 2mm
- FWHM: OIII 7nm, Ha 7nm
- Blocking tange: 300-1000nm
- Blocking depth: >OD4
- Surface quality: 60/40
- Transmitted wavefront RMS: λ/4
- Parallelism: 30s
Coating Technology
- Multi layer anti-reflection coated.
- Non-cementing optical substrate coating.
- Electron-beam gun evaporation with ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on the CWL (central wavelength) so that there is no deviation due to temperature changes during use.
- Precise and homogeneous coatings ensure high values of desired passband and blocking of unwanted offband.
- Every single filter is tested and passed by Optolong before shipping to dealers.
Useful Resources
Filter Cell Specifications
D = Filter Cell Diameter = 31.3 mm / 1.23 in
T = Total Filter Height = 6.8 mm / 0.26 in
C = Filter Cell Height (Excluding Male Thread) = 4.8 mm / 0.18 in
M = Male Thread Length = 2.0 mm / 0.07 in
F = USABLE Female Filter Thread Length = Not threaded, so you cannot stack additional filters
S = Glass Substrate Thickness = 2 mm / 0.07 in
CA = Clear Aperture = 26.1 mm / 1.02 in
Other Information
- Country of Manufacture: China
Optolong L-eXtreme F2 Overview
The Optolong L-eXtreme F2 is a dual-band (500.7 nm and 656.28 nm, FWHM=7 nm) narrowband pass filter that meets the transmission requirements for fast optical systems that have a steep light angle. The transmission wavelengths of the OIII and H-Alpha nebula emission lines pass accurately between f/2 - f/3.3 focal ratios. Optolong has developed this filter specifically for fast focal ratio imaging systems. It has performed well on RASA, HyperStar and other fast focal ratio telescopes.
Key Features
- Ideal for monochrome or one-shot color CMOS cameras as well as digital SLR and mirrorless cameras.
- Quickly obtain clear and detailed images of deep sky nebulae.
- Ideal for fast optical systems, like RASA, Hyperstar and other fast focal ratio telescopes.
- Recommended for use with fast optical systems with a focal ratio between f/2 to f/3.3.
- Cuts through light pollution offering better contrast and more detail in emission nebulas.
Spectrum and Characteristics
- Substrate: Optical glass
- Size: 1.25" mounted (M28.5x0.6 male)
- Thickness: 2mm
- FWHM: OIII 7nm, Ha 7nm
- Blocking tange: 300-1000nm
- Blocking depth: >OD4
- Surface quality: 60/40
- Transmitted wavefront RMS: λ/4
- Parallelism: 30s
Coating Technology
- Multi layer anti-reflection coated.
- Non-cementing optical substrate coating.
- Electron-beam gun evaporation with ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on the CWL (central wavelength) so that there is no deviation due to temperature changes during use.
- Precise and homogeneous coatings ensure high values of desired passband and blocking of unwanted offband.
- Every single filter is tested and passed by Optolong before shipping to dealers.
Optolong L-eXtreme F2 Overview
The Optolong L-eXtreme F2 is a dual-band (500.7 nm and 656.28 nm, FWHM=7 nm) narrowband pass filter that meets the transmission requirements for fast optical systems that have a steep light angle. The transmission wavelengths of the OIII and H-Alpha nebula emission lines pass accurately between f/2 - f/3.3 focal ratios. Optolong has developed this filter specifically for fast focal ratio imaging systems. It has performed well on RASA, HyperStar and other fast focal ratio telescopes.
Key Features
- Ideal for monochrome or one-shot color CMOS cameras as well as digital SLR and mirrorless cameras.
- Quickly obtain clear and detailed images of deep sky nebulae.
- Ideal for fast optical systems, like RASA, Hyperstar and other fast focal ratio telescopes.
- Recommended for use with fast optical systems with a focal ratio between f/2 to f/3.3.
- Cuts through light pollution offering better contrast and more detail in emission nebulas.
Spectrum and Characteristics
- Substrate: Optical glass
- Size: 1.25" mounted (M28.5x0.6 male)
- Thickness: 2mm
- FWHM: OIII 7nm, Ha 7nm
- Blocking tange: 300-1000nm
- Blocking depth: >OD4
- Surface quality: 60/40
- Transmitted wavefront RMS: λ/4
- Parallelism: 30s
Coating Technology
- Multi layer anti-reflection coated.
- Non-cementing optical substrate coating.
- Electron-beam gun evaporation with ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on the CWL (central wavelength) so that there is no deviation due to temperature changes during use.
- Precise and homogeneous coatings ensure high values of desired passband and blocking of unwanted offband.
- Every single filter is tested and passed by Optolong before shipping to dealers.
Useful Resources
Filter Cell Specifications
D = Filter Cell Diameter = 31.3 mm / 1.23 in
T = Total Filter Height = 6.8 mm / 0.26 in
C = Filter Cell Height (Excluding Male Thread) = 4.8 mm / 0.18 in
M = Male Thread Length = 2.0 mm / 0.07 in
F = USABLE Female Filter Thread Length = Not threaded, so you cannot stack additional filters
S = Glass Substrate Thickness = 2 mm / 0.07 in
CA = Clear Aperture = 26.1 mm / 1.02 in
Other Information
- Country of Manufacture: China