Product Description
This Optolong filter set is designed to bring out the best in your astro-photography journey. A great amount of thought went into the way each filter approached their intended purpose. The OIII emission overlaps on blue and green filters with maximum transmission to allow high efficiency and natural color imaging. A designed gap between the green and red filters serves to block out the primary Sodium light pollution line at 589nm and improves color balance and separation.
SII
The Optolong SII filter allows a 6.5nm bandwidth of light centered on a wavelength of 672nm through, and reduces the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor. It also deals with both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). The SII filter is a great choice to use for astrophotography as it will help with contrast and reveal very subtle nebula details.
H-Alpha
The H-Alpha filter is also suitable for viewing on faint emission nebula of H-Alpha line in full moonlight or in severe light pollution. Even better, when used in conjunction with the OIII-CCD and SII-CCD, such as the famous “Pillars of Creation” (M16 Eagle Nebula), you can start to bring your own "Hubble look" images from your backyard. That particular combination of the three filters for imaging, SHO set (H-alpha, OIII-CCD and SII-CCD), can be very helpful when the moon up, or in heavy light pollution, so your equipment is getting used rather than gathering dust.
OIII
The improved Narrowband OIII 6.5nm filter allows a 6.5nm bandwidth of light centered on a wavelength of 500nm through, which corresponds to OIII emission lines, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor. It also deals with both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).
The filters have a steep bandpass to eliminate UV and IR interference. The filters are all very well made. The multi-layer anit-reflection coating is based on an Ion-assisted technology known for durability and Resistance to scratching. The technology also provides stability to the CWL (central wavelength) allowing no deviation with temperature change. The 1/4 wavelength Schott glass filter is housed in a very thin CNC machined housing.. The filter comes in a plastic case to protect your investment when not in use.
