Filtro a banda stretta ZWO H-alpha, SII, OIII 7nm - 31mm circolare non montato

The narrowband ZWO H-alpha, SII, OIII 7nm filters are designed for astrophotography and allow you to produce "Hubble-like" images. By selectively reducing the transmitted wavelengths, these filters suppress the effects of public lighting and the Moon.

The aluminum cell is manufactured by CNC machines that impose high manufacturing precision. The filter is available in 4 formats, including the unmounted circular format of 31mm.

Technical Characteristics

• FWHM (Full Width at Half Maximum) : 7nm (+/-0.5)
• Bandpass: 90% on Ha/S-II/O-III lines
• Infrared cutoff (700/1100nm)
• Schott glass
• Glass thickness: 1.85mm
• Precise optical polishing to ensure a precise wavefront at lambda/4 and parallelism <30" of arc on both surfaces
• Double-sided optical coating
• Anti-reflection treatment
• Cell construction in CNC-machined aluminum

Usage

These filters are ideal for CCD imaging, digital photography (modified camera) and allow you to increase the contrast of nebulae.