B1 B2 B3 B4
Magnification 8x 10x 7x 9x 11x 6x 8x 10x 10x 12x 15x
Obj. Lens diam. 42mm 42mm 45mm 45mm 45mm 30mm 30mm 30mm 56mm 56mm 56mm
Exit Pupil 5.25mm 4.2mm 6.4mm 5mm 4.1mm 5mm 3.75mm 3mm 5.6mm 4.7mm 3.7mm
FOV 7.4° 6.5° 7.4° 7.2° 8.5° 8.2° 6.5° 6.7° 5.5° 4.4°
App. FOV(FOV x Power) 59.2° 65° 51.8° 64.8° 66° 51° 65.6° 65° 67° 66° 66°
Field of view(ft/1000yds) 388 341 388 377 314 446 430 341 351.8 288.8 231
Brightness 27.6 17.6 51.0 25.0 16.7 25.0 14.1 9.0 31.4 21.8 13.9
Light transm (%) 91.9% 90.9% 93.7% 93.7% 94.8% 94.6% 95.2% 94.6% 93.7% 94.2% 94.2%
Twilight fact. 18.3 20.5 17.7 20.1 22.2 13.4 15.5 17.3 23.7 25.9 29.0
Multi Posit. Eyecups Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Eye Relief 18.6mm 16mm 18mm 17.3mm 16.7mm 18.3mm 15.1mm 15.3mm 17mm 18mm 18mm
Near focus 6.6ft 6.6ft 6.5ft 4.9ft 4.9ft 8.2ft 8.2ft 8.2ft 9.8ft 9.8ft 9.8ft
Eye width adj.(mm) 56-73 56-73 56-75 56-75 56-75 56-73 56-73 56-73 55-74 55-74 55-74
Dim. WxHxD (inch) 5x6.2x2.1 5x6.2x2.1 5.7x7.1x2.2 5.7x7.1x2.2 5.7x7.1x2.2 4.7x4.6x1.7 4.7x4.6x1.7 4.7x4.6x1.7 6.1x8.2x2.7 6.1x8.2x2.7 6.1x8.2x2.7
Weight (oz.) 29.13 29.75 33.25 33.25 33.25 16.25 16.25 16.5 48.0 48.0 48.0
Lens Const. Obj. 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED) 3 grps 4 elem (ED)
Lens Const. Ocular 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem. 4 grps 5 elem.
Prisme type Schmidt-Pechan Schmidt-Pechan Abbe-Koenig Abbe-Koenig Abbe-Koenig Schmidt-Pechan Schmidt-Pechan Schmidt-Pechan Abbe-Koenig Abbe-Koenig Abbe-Koenig
Prism refl. Coat. Type Dielectric Dielectric N/A N/A N/A Dielectric Dielectric Dielectric N/A N/A N/A
ED Glass Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Lens coating Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist. Scratch and oil resist.
Diopter correc. (dpt) +/-3 +/-3 +/-2 +/-4 +/-4 +/-2 +/-4 +/-4 +/-2 +/-2 +/-2
Pressure tested 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7) 1m x 30min. (IPX7)
Storage temp. -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F -40°F +158°F
Functional temp. -13°F +140°F -13°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F -4°F +140°F
Frame material Mg Mg Mg Mg Mg Polymer Polymer Polymer Polymer Polymer Polymer
Internal gas purged Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen Nitrogen
Tripod Adaptable Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Origin Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US Jap. And Ass. US