solentbirder
Well-known member
I've seen contradictory figures published for the field of view for these roof prisms. Can an owner let me know what's actually printed on the binocular?
The figures I've seen are:
102m @1000m (Warehouse Express and others)
This equals 5.8 degrees (taking 1 degree as approx. 17.5m), making the apparent FOV 49.3 degrees (8.5x5.8)
336ft @1000yds (Swift website)
This equals 6.4 degrees (taking 1 degree as approx 52.5 feet), making the
apparent FOV 54.4 degrees (8.5x6.4)
There's quite a difference between an apparent field of 49 and 54 degrees so I'm interested to know which is correct (or if my calculation is wrong!)
Thanks for your help.
The figures I've seen are:
102m @1000m (Warehouse Express and others)
This equals 5.8 degrees (taking 1 degree as approx. 17.5m), making the apparent FOV 49.3 degrees (8.5x5.8)
336ft @1000yds (Swift website)
This equals 6.4 degrees (taking 1 degree as approx 52.5 feet), making the
apparent FOV 54.4 degrees (8.5x6.4)
There's quite a difference between an apparent field of 49 and 54 degrees so I'm interested to know which is correct (or if my calculation is wrong!)
Thanks for your help.