Best Rated Binoculars – Optical Stats
Over the past few weeks I have had a few people ask me how I actually rate the binoculars and give them their scores in any particular category that in turn contributes to their overall scope on the Best Binoculars Ratings Scale.
I actually have a different formula or way of doing it for each of the different categories (Body Quality, Body Stats, Optical Components, Quality, Optical Stats, Image Quality, Extras & Details). So what I thought I would do is go through each and explain just how their score is achieved, this way it will hopefully give you a better understanding of them and in turn will hopefully help you to decide on the best binocular for your particular needs.
Optical Stats Score
To start off with I will explain how I come about the score for a binoculars optical stats – which is an overal score of how wide a field of view a binocular has (FOV), the amount of eye-relief (ER) as well as it’s minimum or close focusing distance (CFD). This score is in relation to others in their size and magnification class. I have done it this way because it would be unfair to compare the field of view of a 10x compact with an 8x full sized binocular.
- If CFD <= 6ft they get 10 points
- If CFD <= 7ft they get 9 points
- If CFD <= 8ft they get 8 points
- If CFD <= 9ft they get 7 points
- If CFD <= 10ft they get 6 points
- If CFD <= 12ft they get 5 points
- If CFD <= 13ft they get 4 points
- If CFD <= 14ft they get 3 points
- If CFD <= 15ft they get 2 points
- If ER >= 17mm they get 10 points
- If ER >= 16mm they get 9 points
- If ER >= 15mm they get 8 points
- If ER >= 14mm they get 7 points
- If ER >= 12mm they get 6 points
For Mid & Full Sized binoculars with a magnification of around 8x
If FOV >= 430 ft @1000yds (8.15° / 65°) they get 10 points
If FOV >= 400 ft @1000yds (7.59° / 61°) they get 9 points
If FOV >= 360 ft @1000yds (6.84° / 55°) they get 8 points
If FOV >= 340 ft @1000yds (6.46° / 52°) they get 7 points
If FOV >= 320 ft @1000yds (6.08° / 49°) they get 6 points
For Mid & Full Sized binoculars with a magnification of around 10x
If FOV >= 342 (6.5° / 65°) they get 10 points
If FOV >= 321 (6.1° / 61°) they get 9 points
If FOV >= 316 (6.0° / 60°) they get 8 points
If FOV >= 289 (5.5° / 55°) they get 7 points
If FOV >= 273 (5.2° / 52°) they get 6 points
If FOV >= 257 (4.9° / 49°) they get 5 points
For Compact binoculars with a magnification of around 8x
If FOV >= 342 (6.5° / 65°) they get 10 points
If FOV >= 321 (6.1° / 61°) they get 9 points
If FOV >= 316 (6.0° / 60°) they get 8 points
If FOV >= 289 (5.5° / 55°) they get 7 points
If FOV >= 273 (5.2° / 52°) they get 6 points
If FOV >= 257 (4.9° / 49°) they get 5 points
For Compact binoculars with a magnification of around 10x
If FOV >= 321 (6.1° / 61°) they get 10 points
If FOV >= 316 (6.0° / 60°) they get 9 points
If FOV >= 289 (5.5° / 55°) they get 8 points
If FOV >= 273 (5.2° / 52°) they get 7 points
If FOV >= 257 (4.9° / 49°) they get 6 points
- Fov = Field of view
- CFD = Close focusing distance
- ER = Eye Relief
The Formula is (6x FOV + 2x CFD + ER) / 9 = Optical Stats Score
So as you can see I have weighted the final Optical Stats Score in favour of the binoculars field of view as I believe this to be the most important feature of the three. I hope this all makes sense!