ZWO H-ALPHA 7nm NARROWBAND FILTER Size:1.25" SKU filter set

SKU filter set

Ultra-low thermal expansion fused silica optics

Fully functional astrophotography software to be used with EAGLE or Windows 10 computers

this filter completely blocks the OIII line at 501nm and below

when doing alignment)

ZWO H-ALPHA 7nm NARROWBAND FILTER Size:1.25" SKU filter setThe ZWO 7nm H alpha narrowband filter enhances the contrast of emission and planetary nebulae. These peculiar nebulae emit light only in specific wavelengths (H; OIII; SII) and the narrowband filters have the property to reject all light outside these bands. The passing band or "window" of these filters is 7nm wide. Considering that the visible light spectrum is between 380nm and 740nm, a 7nm filter would block 98% of the unwanted light. As a result,