Hello
I'm working at the optical design of a binocular with wide FOV, 15°-20°.
The key component is the short-but-wide objective; eyepiece will follow.
Questions:
1) Is there any use case / market for low magnification, wide field binoculars?
The Visionking 5x25 seems the only one currently produced with very wide FOV.
There were some old wide models, like the reverse-porro designs 5x25 Bushnell and 4x22 Dowling & Rowe, but they've been discontinued, which means poor sales.
Other 4x in production, like Pentax 4x20 and Nikon 4x10, have very narrow FOV.
The "Ultrawide" Porros raging in the 1980s, were yes wide but mostly 8x-7x.
2) Which combination of magnification / exit pupil / AFOV is most desirable?
I'm oriented toward 60° eyepiece AFOV, because wider it becomes difficult, either not sharp, or short eye relief, otherwise it leads to expensive monsters like the Nikon WX.
Here some examples of feasible models:
4x25 Roof
FOV 15°, AFOV 60°, exit pupil 5 mm
Roof prism; a remake (same overall size) of the Visionking 5x25, with same TFOV, narrower AFOV, hopefully cleaner image and similar price.
4x20 Porro
FOV 15°, AFOV 60°, exit pupil 5 mm
Porro prism, good quality optics, chassis will be like the recent 6.5x32 APM/KUO
3x21 Big
FOV 20°, AFOV 60°, exit pupil 7 mm
It needs massive prisms, like Sard 6x42 or other old ultrawides
3x9 Roof
FOV 20°, AFOV 60°, exit pupil 3mm
small lightweight roof binocular, medium-low cost
Same for a 4x12 with 15° FOV
3x21 Finderscope
FOV 15°, AFOV 45°, exit pupil 7mm
Monocular or finderscope with Roof prism, with narrow view but large exit pupil and long eye relief - almost like a riflescope
The smaller FOV allows for prism of reasonable size
Vote your favorite!
It may become reality.
Edited by patta, 14 November 2024 - 10:42 AM.
