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BETTER OUTDOOR EXPERIENCES

WITH WIDE-, ULTRA-WIDE- &

XTRA-WIDE-FIELD BINOCULARS

by

Robin Leech, PhD, PBiol

(releech@)

ABSTRACT

Binoculars with wide-field, ultra-wide-field to extra-wide-field of view (FoV), and the apparent field of view (AFOV) of lower-powers (4X-6X) are suggested for those wanting exhilarating new experiences. Examples are sightseeing from high vantage points (buildings to mountains). They are also suggested for those attending sporting and auto racing events, travelling, hiking and hunting in forested and open country mix, whether in plains, hilly or mountainous areas. Binoculars with these features are excellent for viewing and using in full daylight to twilight conditions. These kinds of binoculars will give a whole new meaning and perspective to viewing pleasures. It is the difference between checking out a bush versus checking out the whole forest in one glance.

Eight pairs of binoculars are compared: the Bushnell 8X30 are “normal” binoculars; the Leitz Trinovid 8X20 are “little dinkies”; the Bushnell 6X25, 7X35 and the Leitz Amplivid 6X24 are wide-field binoculars; the VisionKing 5X25 are ultra-wide-field binoculars; and the Bushnell 4X30 are Xtra-wide-field binoculars. The Bushnell 4X30 binoculars are fixed-focus.

INTRODUCTION AND DISCUSSION

In discussing with others about the kinds of binoculars they have, I encountered unexpected extremes: “Yes, I have a pair somewhere in the house, but would have to look to find them!” When I asked about make and specs, I got shoulder shrugs. The other extreme is, “I’m a binocular junkie. I have 4 pairs of binoculars.” And he knows the makes and specs for each of them. I didn’t have the heart to tell him that I have over 50 pairs.

It has been my experience that most people, when purchasing their first pair of binoculars, check out several pairs in the store, select one for life. For some, purchasing the first pair of binoculars opens the way for the purchase of more.

In this article, I suggest that binoculars with a wider field of view (FoV) and slightly lower magnification will offer a super visual experience without a huge outlay of money, usually between $50 and $80.

If you have never looked through a pair of wide-field, ultra-wide-field or extra-wide-field binoculars, you are in for a surprise and a treat when you do! What are these kinds of binocular? What feature or features does a pair of binoculars have to have in order to be considered in these categories? There are two features. The first feature is the field of view (FoV). The FoV of wide-field, ultra-wide-field and extra-wide-field binoculars is arbitrarily set at a minimum of 10 ͦ up to about 17 ͦ .

There are three terms that discuss the viewing area of a pair of binoculars. The first is the Angle of View (AoV), which is expressed in degrees (e.g., 8 ͦ , 10 ͦ ). The second term is Field of View (FoV), which measures feet @ 1000 yards; and metres @ 1000 metres. The third term is Apparent Field of View (AFoV), which is the FoV multiplied by the Power/Magnification, e.g., 10 ͦ times 6X = 60 ͦ . This value is important when comparing binoculars of different magnifications.

The FoV of a pair of binoculars, if it is written at all, is usually on the right or left prism plate, or the upper hinge cap. It is written in one of 3 formats:

Degrees (ͦ ); feet @ 1000 yards; or metres @ 1000 metres.

The second feature for wide-field binoculars is the power or magnification. It is the first number of two written on the binoculars (e.g., 4X30; 5X25 and 6X30). These are low powers according manufacturers’ guidelines, and what most outdoorsy people think or feel they need. I want to alter that perception of needed higher powers (8X-10X) to lower powers of 4X-6X. Lower powers usually come with a wider FoV. We need to get away from the “more power is better” concept.

The wide-, ultra-wide- and extra-wide-field binoculars, and lower powers (4X-6X), are for those wanting exhilarating and “WOW!” experiences. The places to go are high-vantage points in/on buildings to mountains. They are also suggested for those attending sporting and auto racing events, travelling, hiking and hunting in forested and Parkland areas, and the Rocky Mountain foothills. In other words, where there are lots of trees and bushes. They are rarely used in the open Prairie and Grasslands. The vast open Prairie and Grasslands are reserved for high-powered binocular and spotting scope – areas where there is a continuous feeling of openness and vastness. Spotting scopes are also used for sheep hunting.

The binoculars with wider FoVs are small, usually have roof prisms (though some have Porro Prism Type I), and are either small enough to drop into a pocket as is, or can be folded and put into a shirt or jacket pocket. They come with a thin, lace-like neck strap. I recommend small binoculars over all the monoculars I have used. Monoculars simply do not throw-up-to-view readily. In comparison, I have found that binoculars are readily on target, whereas monoculars are not. Binoculars are also 3-D or stereo, whereas monoculars are not.

During the last few years, I have discovered some really neat small binoculars that are only slightly larger than the little dinkies (e.g., Leitz 8X20) (Figs 1, 2), yet considerably smaller than the usual 8X30 (Fig. 3) or the 7X35 (Fig. 4), both of which are Porro prism Type I. The binoculars I am suggesting are ones that have lower powers, e.g., 4X to 6X, and even 8X, and which also have ultra-wide- to extra-wide FoV.

Table 1. Comparison of a “little dinky” binocular vs a normal-sized binocular. Note especially the degree size and weight difference. The Bushnell 8X30 is a normal pair of binoculars.

Binocular Degree FoV in Feet FoV in Metres Wt Size

|Leitz/Trinovid 8x20 |6.5 ͦ |341ft@1000yds |114m@1000m |233 g |91/63 |

|Bushnell 8X30 |8 ͦ 45’ |459ft@1000yds |153m@1000m |540 g |114/160 |

[pic] [pic]

Fig.1. Leitz 8X20 not folded. Fig. 2. Leitz 8X20 folded.

[pic]

Fig.3. Bushnell 8X30, IF, 8 ͦ 45’ FoV.

The Bushnell 8X30 I used in Antarctica from 1959-61, and from then till 1970 I used them for hunting. In the summer of 1970, I “felt the pinch” of needing more power, so I purchased a pair of Leitz Trinovid 10X40 (FoV 122m). The 10X40 Trinovids are marvellous binoculars, but for a little bit more power, I lost 31m of FoV (that is over 20% of my previous total FoV). Was it worth it? Let me put it this way! It took me several years, but I returned to my 8X30 binoculars.

I did not hunt with my SARD 6X42 (with almost 12 ͦ of FoV) because they are so heavy. But, desire for a pair of wide-field binoculars for outdoorsy use did not go away. So, I solved the yearning another way.

I did something different. I purchased a pair of VisionKing 5X25 Ultra-wide field binoculars (Figs 8, 9 and Table 2) for general day and dawn/dusk scanning. Actually with the 5X25 binoculars, I do not need to scan. The FoV is so large that all I do is hold them up to my eyes. I don’t need to move right or left.

Not long afterwards, I purchased a pair of Bushnell 4X30 Xtra-wide Field (Figs 10, 11, and Table 2), mostly because I have always been interested in wider-than-normal FoV binoculars. See Table 2 for the specifications for the VisionKing 5X25 with roof prisms, and the 4X30 with Porro Prism Type I.

The 4X30 Bushnells are a bit fat and blocky, and are not readily carried in pockets, though they would fit into a small knapsack, rucksack or shoulder carry sack. They come with a small soft, zippered bag. But the VisionKings are small enough, and light enough, to fit into any pocket. The kicker is that the VisionKing 5X25, with the 5 mm exit pupil has tremendous light gathering for twilight viewing. A second pair of binoculars, say 7X50 or 8X56, is not needed.

About the only time I can think of that someone will need gobs of power is when bird watching, hunting Bighorn Sheep in the mountains, and Pronghorn Antelope on the bald Prairie and Grasslands. These wide-open spaces and distance are where high power is the issue, not wide-field viewing. My experience with bird watching is that even when viewing birds from 3-4 metres, 8X is superb.

Table 2. Comparisons of the FoVs of wide field, ultra-wide field and extra-wide-field binoculars. The visual FoV between 10.0 ͦ and 15.8 ͦ is remarkable, but between 10.0 ͦ and 17.1 ͦ is astounding. The Bushnell 7X35 wide-field is the only “normal” pair of binoculars in Table 2. Notice the weight differences.

Binoculars Degrees FoV in Feet FoV in Metres Weight Size (mm)

|Bushnell 7X35 | 10.0 ͦ |525t@1000yds |175m@1000m | 930 g | 125h / 200w |

|Bushnell 6X25 | 11.0 ͦ |578ft@1000yds |193m@1000m | 380 g | 63h / 118w |

|Leitz/Amplivid 6X24 | 12.1 ͦ |636ft@1000yds |212m@1000m | 370 g | 112h / 113w |

|VisionKing 5X25 | 15.8 ͦ |830ft@1000yds |277m@1000m | 590 g | 65h / 118w |

|Bushnell 4X30 | 17.1 ͦ |900ft@1000yds |300m@1000m | 411 g | 103h / 145w |

The 7X35 Bushnell with a 10 ͦ FoV (Fig. 4 and Table 2) and the Bushnell 6X24 (Fig. 5 and Table 2) with an 11 ͦ FoV, are in the wide-field category, but otherwise they are pretty much normal binoculars.

[pic] [pic]

Fig.4.Bushnell 7X35. 10 ͦ FoV. Fig.5.Bushnell 6X25. 11.0 ͦ FoV.

The Leitz Trinovid 6X24 binoculars have roof prisms, which are visible in Fig. 6. The 6X24 binoculars have essentially the same FoV as the SARD 6X42, but in terms of weight, they are vastly different. The 6X24 binoculars are pocket sized.

[pic] [pic]

Fig.6. Leitz Trinovid 6X24, CF. Fig.7. Leitz Trinovid 6X24, CF.

The VisionKing 5X25 (Fig. 8) binoculars have an exit pupil of 5 mm, which makes them much easier to use than the Leitz 6X24 with a 4 mm exit pupil. They cost $50- $80 delivered, and are the best of several Chinese-made binoculars I have examined. But, as with the Bushnell 4X30, prices vary, so check around.

[pic] [pic]

Fig.8. VisionKing 5X25, 15.8 ͦ FoV. Fig.9. VisionKing 5X25, top view.

With an FoV of 17.1 ͦ , the Bushnell 4X30 Xtra-wide binoculars (Figs 10, 11, and Table 2) have the widest FoV of all binoculars known to me (900 ft @ 1000 yds) (that is, more than 3 times wider than a football field is long). They are also fixed-focus, so these can be called point-and-look. For action events (football, car racing), they are unbeatable from close to several hundred metres away. They are about $80 delivered to your door. Prices vary quite a bit.

[pic] [pic]

Fig.10. Bushnell 4X30 sideview. Fig.11. Bushnell 4X30 left objective.

For more discussion on wide-field binoculars, go to Google and type in this:

Binoculars with the widest field of view.

Also check out this link:



CONCLUSIONS

For active sporting events and superb viewing of hiking and hunting areas, the VisionKing 5X25 and the Bushnell 4X30 cannot be beat. They are also light and not very expensive, and can be purchased readily on the internet. I do admit at first to being suspicious about the VisionKing 5X25 quality when I ordered them, but my pair is superb. The link in the References is an excellent source of definitions.

ACKNOWLEDGEMENTS

My brother Tom is thanked for reviewing the text and offering positive suggestions and comments. Tanya Spencer, PhD, and Andrew Eisenhawer, are thanked for assistance with picture insertions and table alterations.

REFERENCES

Google site: Binoculars with widest field of view.



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