Optolong Filters L-Quad Enhance 2”

Optolong Filters L-Quad Enhance 2” is a quad-band narrowband filter specifically designed to capture emission nebulae more contrastily with color cameras and DSLRs. The filter combines four transmission windows (H-beta, O-III, H-alpha and S-II) while blocking disturbing artificial light from sodium and mercury lamps, as well as the natural sky glow of the atmosphere. The result: greatly enhanced contrast and a darker sky background, even when observing or photographing from urban areas.

Unlike single- or dual-band filters, the L-Quad Enhance offers more flexibility by allowing multiple emission lines to pass through at the same time. This is especially an advantage for astrophotographers working with One-Shot-Color cameras (such as ZWO's popular CMOS models), as the different channels are captured in one shot. For DSLR users, this means less need for post-processing and more natural colors.

The filter is constructed of high-quality Schott glass and coated with a durable IBAD (ion beam assisted deposition) coating. This coating makes it scratch resistant, stable to temperature changes and guarantees high transmission in the pass bands.

Application
The Optolong Filters L-Quad Enhance 2” filter is ideal for astrophotography in areas with moderate to heavy light pollution. It is ideally suited for emission nebulae such as the Orion Nebula, Veil Nebula, Lagoon Nebula and Horsehead Nebula. Reflection nebulae and galaxies benefit less from this filter; for these, the L-Pro is more suitable. The filter can be used with DSLRs, OSC astro cameras and CCDs. Not suitable as a solar filter.

Specifications

• Type: quad-band narrowband light pollution filter
• Barrel size: 2”
• Material: shot glass
• Passed spectral lines: H-beta, O-III, H-alpha, S-II
• Transmission: approx. 90-95% in the pass-through tires
• Coating: IBAD, scratch resistant and temperature resistant
• Usage: Astrophotography with DSLR, CMOS (One-Shot-Color) and CCD
• Not suitable as a sunscreen