Used Baader O-III Nebula Visual Filter (10nm), 2" Pier Extension which provide high contrast viewing

which provide high contrast viewing while minimizing chromatic aberration

Quantum Efficiency

with grip traction knurled right into the metal

the highspeed version is the best choice

50mm achromatic objective lens with adjustable focus

Used Baader O-III Nebula Visual Filter (10nm), 2" Pier Extension which provide high contrast viewingCondition: This is a used Baader O III 10nm visual filter in very good condition with mostly clean optics. There is some minor spotting; see the photos. It comes in its original jewel case. Description: Quick Overview Baader 2 OIII filter improves contrast of nebulae for visual observation and imaging 10nm passband includes OIII (501nm) and H Beta (486nm) wavelengths emitted by diffuse and planetary nebulae and supernova remnants Superior fine optical