FACTORY NOT MARKED NIGHT OWL
2" about 50mm F1//F1.2 near OBJECTIVE LENS.
NEW OLD STOCK.
IT HAS MIDDLE-BARREL M42 SCREW MOUNT.
DIAMETER BELLOW SCREW 34.5mm.
May BE ADAPTED TO YOUR OPTICS
With HELP of m42 MACRO TUBE SETS.
IT IS ULTRA FAST LENS like F1 about.
IT HAS near 1mm INFINITY FOCAL PLANE DISTANCE
FROM REAR ELEMENT D19mm, REAR BARREL D27mm, 91mm LONG.
FRONT ELEMENT D43mm+.
FILTER SCREW 46mm.
LENS FOCUSING.
SCREW M42, DIAMETER UNDER SCREW 34.5MM,
BARREL DIAMETER OVER SCREW 49MM, 91mm LONG.
USING as EYEPIECE LENS HAS
INDEFINITELY LONG near EYE RELIEF: 3cm -30CM-50CM-100CM.
ACTUAL RELIEF WILL DEPENDING ON YOUR OBJECTIV LENS:
FROM FEW INCHES
To FEW FEET+ AFAR - IF LARGE OBJECTIV LENS USED.
BRIGHT OPTICS MADE for INFRARED NIGHT USE by NIGHT OWL.
EXTRIMELY BENEFITIAL AS EXPEREMENTAL VIEWING OCULAR.
THIS DESCRIPTION is APROXIMATE.
EXPERIMENTAL APPLICATION OF LENS USUALLY
FOR ADVANCED USERS.