Astrophotography has seen significant advancements, and filters are crucial in capturing deep-sky objects. The Askar Colour Magic Ultra E2 Duo Narrowband Filter enhances imaging of emission nebulae and supernova remnants. This article delves into its features, specifications, and performance.
Key features
Here are some of the key features of the newly launched filter:
- Dual Narrowband Design: The filter targets two specific wavelengths: 500.7 nm (Oxygen III) and 672.4 nm (Sulfur II). This dual-band approach allows simultaneous capture of both emission lines, enhancing the detail in images of nebulae and other deep-sky objects.
- High Transmission Rates: With peak transmittance exceeding 85% at both targeted wavelengths, the filter ensures that a significant amount of desired light reaches the sensor. This high efficiency is crucial for capturing faint astronomical objects.
- Narrow Bandwidths: The filter boasts Full Width at Half Maximum (FWHM) values of approximately 3-4 nm for both OIII and SII. Such narrow bandwidths effectively isolate the desired emission lines, reducing the impact of light pollution and enhancing contrast.
- Optical Quality: Featuring a surface quality of 60/40 and parallelism of 30 arcseconds, the filter maintains image sharpness and minimizes distortions.
Technical specifications
- Central Wavelengths (CWL): 500.7 nm (OIII) and 672.4 nm (SII)
- Bandwidth (FWHM): Approximately 3–4 nm for both OIII and SII
- Peak Transmission: Over 85%
- Optical Density: ≥OD5 across 200–1100 nm, ensuring effective blocking of unwanted light
- Surface Quality: 60/40
- Parallelism: 30 arcseconds
- Filter Thickness: 1.85 ± 0.05 mm
Performance in astrophotography
The Askar Colour Magic Ultra E2 filter is particularly beneficial for astrophotographers using one-shot color (OSC) cameras. By capturing both OIII and SII emissions simultaneously, it simplifies the imaging process and reduces the need for multiple exposures.
Its narrow bandwidths effectively suppress light pollution, making it suitable for imaging in urban environments. The high transmission rates ensure that even faint details in nebulae are captured with clarity.
Compatibility and usage
The filter is mounted in a 2″ threaded cell, making it compatible with a wide range of holders. Its design ensures full-frame sensor coverage, catering to both amateur and professional astrophotographers. When paired with telescopes of various focal ratios, the filter maintains performance.
Price and availability
The filter is yet to be available for order or pre-order and there has been no definite words from Askar regarding its price. However, one can expect it to be priced around $600.
The Askar Colour Magic Ultra E2 Duo Narrowband Filter stands out as a valuable tool for astrophotographers aiming to capture detailed images of deep-sky objects. Its dual-band design, high transmission rates, and narrow bandwidths contribute to enhanced image quality, especially in light-polluted environments. By simplifying the imaging process for OSC camera users and maintaining compatibility with various equipment, it offers both convenience and performance. As with any specialized equipment, users should ensure the filter aligns with their specific needs and setup for the best results.
Clear skies!
