The ZWO Ha 7nm 1.25-Inch Filter is specifically designed to capture the hydrogen alpha (Hα) emission line at a wavelength of 656.3nm. This filter excels in enhancing the contrast between nebulae and the night sky, making it ideal for capturing rich details of deep-sky objects, especially in areas affected by light pollution.

This filter is engineered to significantly reduce the transmission of unwanted wavelengths produced by artificial lighting, including mercury vapor and sodium vapor lights, as well as natural skyglow caused by neutral oxygen emissions in our atmosphere. While it does not increase the brightness of the nebula, it enhances the contrast, making the nebula stand out more distinctly against the dark sky. The light transmission rate comes up to 80% . It can be used as part of two-band, three-band, or other false-colour images, as well as being combined as a luminance layer or as an addition to the red channel with full-colour filters. They are specially designed for telescopes with a focal ratio that is either equal to or higher than f/5. When used in combination with S-II and OIII filters (SHO Set), it supports tricolor CCD astrophotography, offering a comprehensive solution for capturing detailed images of deep-sky objects.

Technical Parameters:

• Size: 1.25 inches
• Thickness: 5.5mm + 2.5mm (thread)
• Glass Thickness: 1.85mm
• Thread: M28.5 x 0.6 male thread

About ZWO Optical

Established in 2011, ZWO Optical is a fast-growing global astroimaging camera powerhouse based in Suzhou, China. Known for its iconic ZWO ASI 120MM Monochrome CMOS Camera, the first-ever planetary CMOS camera to beat a CCD in the early 2010s, ZWO has  pioneered new astroimaging technology with revolutionary new features, including USB 3,0, cooled systems, ADC and more. Today, ZWO Cameras is known by every passionate astrophotographer and is available in over 25 countries world-wide. 

Product Code: Ha7nm1.25