Optolong SHO 3nm Filter Kit 36MM Unmounted (OPT-SHO-3NM-KIT-36MM) Tripod unique optical design and the

unique optical design and the subsequently high-quality imaging results

It also uses iOptron's ultra-quiet

Focal Length: 18

No need to buy another set of filter drawer or slider when you buy new cameras or telescopes

and Z-axis to realign your phone with the eyepiece

Optolong SHO 3nm Filter Kit 36MM Unmounted (OPT-SHO-3NM-KIT-36MM) Tripod unique optical design and theOptolong SHO 3nm filter kit includes SII 3nm, H Alpha 3nm, and OIII 3nm narrow band filters, generally working with astronomical monochrome cooling CCD and modified DSLR imaging in each single channel. Corresponding with RGB channel (HA, OIII, SII), photographers can process Hubble images by astronomical post processing software. Extra narrowband SIICCD3nm filter (Sulfur II for CCD) is designed for nebula observation allowing 3nm bandwidth of light