The two-band Optolong UHC 2 "filter is an excellent tool for photographing deep sky objects in conditions of high light pollution.
Optolong Ultra High Contrast (UHC) combines the ability to almost completely eliminate the undesirable component originating from sodium and mercury lamps with high transmission for the most important spectral lines from the point of view of astrophotography, such as Hα, Hβ, NII, SII and OIII. In addition, this filter allows a large proportion of red light to pass through, allowing for great results when photographing subjects such as the M42 nebula in Orion.
In order to further improve the optical parameters, this filter is covered with a full multi-layer anti-reflection coating applied using ion implantation techniques. Thanks to this, the coatings are not only perfect in terms of optics, but also very durable and scratch-resistant.
• broadband high transmission filter for the most important spectral lines such as Hα, Hβ, NII, SII and OIII
• high red light transmittance
• efficiency of cutting light pollution on the level> 99%
• scratch-resistant multi-layer anti-reflective coating
• filter type: broadband filter
• filter diameter: 2 "
• transmitted bands: Hα (656.3 nm), Hβ (486.1), OIII (495.9 nm), OIII (500.7 nm), SII (672 nm), NII (654 nm, 658 nm)
• maximum transmission:> 95%
• blocked bands: mercury lamps (435.8 nm, 546.1 nm, 577 nm, 578.1 nm), sodium lamps (598 nm, 589.6 nm, 615.4 nm, 616.1 nm)
• efficiency in blocking light pollution:> 99%
• equivalent optical density for blocked lines: OD3
• filter material: optical glass
• type of coating: full multilayer coating (FMC)
• surface quality index: 60/40 (in accordance with MIL-O-13830A and MIL-C-48497A standards)
• parallelism: 30 "
• RMS execution accuracy: λ / 4
• frame material: black anodised aluminum
• Optolong UHC 2 "filter