Optolong L-Para (L-Parallels) 2" Filter
L-Para is a new 10nm narrow band dual light pollution filter. The FWHM of L-Para is 10nm for OIII (500.7nm) and H-alpha (656.3 nm) respectively. The transmittance of the nebulae emission lines in are both above 85% in system with focal ratios of F2 and above. It effectively filters the emission lines of mercury, sodium and LED lamps.
At the same time, it has excellent contrast and anti-halo characteristics, allowing it to capture detailed and vivid nebula images. L-Para is suitable for both normal optical systems and fast optical systems, such as RASA and Hyperstar systems.
Even when the light is incident at an oblique angle, it can maintain high transmission rates to give you a clear and accurate shooting experience.
Advantageous features offered:
- Wide compatibility: a narrow-band dual filter suitable for all telescope systems, adaptable to fast optics (focal ratios of F2, F2.8, F3.2 and F4).
F2, F2.8, F3.2, F4) as well as various standard/normal focal ratio telescopes.
- Resistance to light pollution: Effectively cuts emission lines from mercury lamps, sodium lamps, LEDs and other sources of light pollution.
light pollution sources, making it applicable to Bortle Scale1-7 dark skies.
- High transmission rate: In systems with a focal ratio of F2 and higher, the transmittance of the emission lines of nebulae OIII and Ha exceeds 85%
OIII and Ha nebulae exceeds 85%, resulting in higher imaging efficiency.
- Excellent contrast: The high transmittance of the nebulae emission lines (OIII and Ha), combined with a deep cut-off of the light pollution bands, significantly improves image contrast and detail.
light contamination significantly improves the contrast and richness of image detail.
- Anti-halo characteristics: The design has been subjected to several rounds of optimizations and many times of repeated
The design has undergone several rounds of optimizations and many times of repeated testing, resulting in a marked improvement in antihalo performance, improving the capture of bright stars.
L-Para FILTER SPECTRUM:
According to the characteristics of the emission lines of celestial bodies and light pollution, as well as the characteristics of the normal telescope and fast ratio imaging system, L-Para has maintained high transmittance in OIII and Ha, while blocking the emission lines of light pollution.
SPECIFICATION: optical glass
- Glass Thickness: 1.85mm
- FWHM OIII: 10±0.5nm
- Ha: 10±0.5nm
- Transmittance Tabs>85% @500.7nm&656.3nm
- Blocking range 300-1000nm
- Blocking OD ave>4
- Surface quality 60/40
*This curve is for reference only. We will continue to optimize the product according to actual tests, and this curve is not used as the final product data.
At the moment it is only available in 2": M48×0.75 format
HALO TESTING
Filter Optolong L-Para
Nebula NGC 7000/Star level 1.24
68mm F3.9+ASI 6200MC、Single300s
The magnified star looks like this:
Filter Optolong L-Para (L-Parallels) 2"
