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Getting an Eye on the Game - Finding the Right Binoculars
Ed Note: I wrote this article in 1997 and some of the models mentioned herein may no longer be available. However, the evaluation techniques described still apply.
I recently decided I needed to replace my aging binoculars, a pair of Bushnell Sportview 7x35 wide angle. I had long recognized their poor performance, particularly in the very early morning and late evening when the deer are moving. I wanted to get a more powerful pair of binoculars that offered low-light performance similar to my Leupold 3.5-10x50 riflescope.
I was able to borrow a variety of binoculars to test side-by-side, a method I heartily recommend. The four models shown below represent the lower cost models from their respective manufacturers. Table 1 shows a summary comparison of specifications.
Table 1: Binocular Summary
Manufacturer and Model / FOV1000 yd, ft / Eye Relief, mm / Weight, oz. / Street Price
[*]Minolta Standard XL 10x50 WA / 341 / 18 / 35 / $150[*]Wind River 10x50 / 275 / 16 / 28 / $200[*]Steiner Big Horn 9x40G / 300 / 20 / 26 / $400[*]Swift Audubon 8.5x44 ED / 430 / 15 / 29 / $450 [/list]
Minolta Standard XL 10x50 WA
The Minoltas are center-focus, BaK-4 porro prism binoculars. A right eyepiece diopter adjustment compensates for the user's difference in left and right eye acuity.
The Minoltas are covered with a thin slate gray rubber finish. They were the largest binoculars tested, weighing in about ½ lb more than the lightest.
Lenses are protected by individual covers. The eyepiece lens caps fit inside the eyecups, requiring the eyecups to be extended before the covers will fit. The Minoltas came with a thin, plain neck strap and a soft-side carrying case.
Wind River 10x50
The 10x models feature porro prisms and center focusing adjustments. A right eyepiece diopter adjustment compensates for the user's difference in left and right eye acuity.
The Wind Rivers were the cheapest looking of the tested binoculars. They reminded me of my old Bushnells. The soft black leatherette finish was bubbled in places. Accent lettering is gold.
However, for a 10x50, they are much smaller than the Minoltas. They are almost exactly the size of the Steiners while offering a more powerful objective.
Lenses are protected by individual covers. The eyepiece lens caps fit over the eyecups. The eyecups must be extended before the covers will fit. The Wind Rivers come with a thin nylon neck strap and soft-side cordura carrying case.
Wind River products feature a limited lifetime warranty.
Steiner Big Horn 9x40G
The 9x40 G "Big Horn" is a military/marine binocular. They would be considered a mid-grade model. Like all the Steiner binoculars, once individually focused to your eyes, they are focus-free.
The Steiners are covered with a thick green armoring decorated with gold accent lettering. Due to their construction, they are waterproof.
The Steiners do not come with a carrying case. Instead, a wide neck strap is fitted and a one-piece eyecup cover slides on it. The cover is large enough to fit over eyecups that are collapsed for glasses wearers. On the objective end, individual caps are attached to each lens barrels so they cannot be lost. They come with a 10 year warranty
Swift Audubon 8.5x44 ED
The Swifts are center-focus, porro prism binoculars. A right eyepiece diopter adjustment compensates for the user's difference in left and right eye acuity. They were the smallest binocular tested.
This Swift model was equipped with ED ("extra-low dispersion") glass. The longer the focal length, the more visible chromatic aberration is. ED glass has lower dispersion, so it reduces the amount of chromatic aberration.
They are the best-looking and smallest pair tested. A fine, hard-wrinkle finish is accented with a red stripe around the objective lenses. Accent lettering is gold.
The objective lenses are protected by individual covers, while the eyepieces share a cap that fits over the eyecups. The cover will fit over eyecups that are collapsed for glasses wearers.
The Swifts came with a foam padded neck strap and a soft-side carrying case. They have a lifetime warranty.
Test Procedures
I had never tested binoculars before so my first question was “How do I test binoculars?” I did an Internet search and came up with some good ideas (e.g., http://www.birdwatching.com/optics/binocsbwd95.html). Then I added additional ones as I thought of other issues I had experienced with optics. Since I am a glasses wearer, I also had to conduct some tests with and without glasses.
Most of the tests were conducted at ranges between 300 and 1000 yards. Low light evaluations were also made at shorter distances.
Test 1: Exit Pupil Examination
Take the binoculars and hold it at arms length with the objective lens (the lens that is furthest from your eye) facing away from you. You should see a small circle of light, called the exit pupil. Better quality binoculars will show a circle that is clear and easy to see. If the binoculars are of poor quality you may actually see a square area with shading outside of the square area around the edges of the lens.
None of the tested binoculars demonstrated any objective squareness. The Steiners were perfectly round, the Wind Rivers the next best, followed by the Swifts and Minoltas. With my old Bushnells, I could see the square with the shading around it.
Test 2: Low Light Evaluation
One way to immediately know if you are getting a good quality pair of binoculars is to look at them in low light conditions Try going to a store around dusk and look outside with the binoculars. However, if you're unable to go to a store at that time of day, look around in the store for a dark corner and try focusing different pairs of binoculars there. It is easier to see quality differences in binoculars in low light rather than in bright light.
I found this to be the hardest test to conduct. All these binoculars are so good that it has to be really late in the evening or early in the morning to observe their differences. At these times, the lighting conditions are changing rapidly, and, as a result, I spent several mornings and evenings trying to fairly evaluate the four.
I also found it was imperative to have the interpupillary distance (IPD) set correctly. If the IPD is too short, the binoculars will appear dark. Widening the IPD brightens the binoculars to a point.
I had always set the IPD by looking through the binoculars and adjusting until I had a good circle of view. Since each pair has a IPD scale on the hinge, I had my IPD measured so I could tell how accurate the scales were. Using the circle method for setting the IPD, I found I consistently set the distance less than the correct scale value for all the binoculars except the Steiners. For the testing, I set each pair to the correct IPD on the scale.
With its large exit pupil (44/8.5 = 5.2 mm), it should come as no surprise that the Swifts were the brightest. However, the advantage is small, and the power of the Minolta helps it to seem brighter at times. The Steiner has the smallest exit pupil, yet still outperforms the larger Wind Rivers.
Test 3: Distortion
Poor quality lenses in binoculars will result in some distortion. In order to try to find this, here is a simple exercise. When you are looking through the binoculars, focus on a subject that has straight lines. It can be either vertical, horizontal or both. For example, if you are looking out a window and there is a telephone pole, adjust the binoculars so the telephone pole is at the edge of the image. If the telephone pole seems distorted and seems to be leaning outward this is known as barrel distortion. If it seems to be leaning inward towards the center of the lens this is called pin-cushion distortion. While most binoculars have this to a certain extent, your goal here is to check for the degree of the distortion and determine what is acceptable for you.
This test was probably the least important to me so I spent less time with it. All the tested binoculars exhibit a small degree of barrel distortion. However, I thought they were all about the same, and it wasn’t noticeable. I did not observe pin-cushion in any of the binoculars.
Test 4: Edge Focus
Look through the binoculars and find a subject and make sure it is dead center in the middle of the lens. Focus on it and then move the binoculars slightly so the subject that was in sharp focus is now at a far edge of the binoculars. Check to make sure if it is as sharp as it was when it was in the center of the binoculars. Remember any binoculars may exhibit some of these problems to some degree, so your purpose here is to compare one pair against the other to determine what is best for you.
For this test, I judged the distance from the edge of the lens in which the target lost focus. I found the Steiner to have exceptional edge clarity, right to the very edge. The Wind River was the second best. Next were the Minoltas, followed by the Swifts. At the extreme edge, these last two had about the same degree of fuzziness. The results of this test surprised me the most. The Swifts lost focus very early and were distinctly worse than the Steiners.
Test 5: Field of View
Field-of-view (FOV) is important for viewing moving game. A wide FOV will help the user locate the game in the binocular. This test was made to check the relative FOV of the binoculars. By observing objects in the distance, the binoculars were rated for FOV.
As expected the Swifts, the lowest power binocular tested, had the largest FOV. The Minoltas were the next best, and the Steiners were next. The Wind River had the most limited FOV.
This test confirmed the relative ranking expected according to the manufacturer’s claims. The Minoltas, one of the most powerful binoculars tested, were outstanding performers
Test 6: Field-of-View with Glasses
With eyeglasses, FOV may be reduced due to the eye relief and alignment problems. To check for problems, the relative FOV test was repeated with my glasses on.
In this test, the Minoltas had the widest FOV, followed by the Swifts, the Steiners, and the Wind Rivers.
Test 7: Low-Angle Sun
I created this test to simulate those late mornings and late afternoons when you may find yourself looking into the low-angle sun. The test consisted of positioning the binocular so that the sun was just out of the top of the lens and then observing any glare on the lens.
The Minoltas were superb in this test, showing absolutely no glare. The Swifts showed a rosy tint on the top portion of the lens. The Steiners were the most distracting with what appeared to be an internal reflection on the bottom portion of the lens. Cloudy, hazy weather prohibited testing the Wind River for sun glare.
Test 8: Ergonomics
Each binocular had its unique ergonomics characteristics. The Minoltas were the largest and heaviest overall. They also have unusually large eyecups, 1.675” diameter compared to 1.375” for all others.
The Swifts are lightweight, compact, and the wrinkle finish has a good feel. The center-focus knob is wide and has a soft rubber coating.
The Steiners are also lightweight, and the rubber armor coating with built-in lens caps make a good package. Once the focus was set, I didn’t have to change it. The Steiners also had the widest neck strap, but the hard plastic adjustment buckle landed right on the back of my neck.
The Wind Rivers feel comfortable in your hands. The center-focus knob is actually wider than the Swift’s, but has a hard rubber coating. Some slop was felt in the focusing adjustments.
Test 9: Other Impressions
Another "test" I conducted was to get the input of others and how they rated the models. My wife accompanied me one afternoon for some bright daylight testing. She liked the Swift for their field of view, clarity, and light weight. My oldest son liked the clarity of the Steiners best and the Minoltas next. The younger son favored the Swifts and then rated the Minoltas second best.
Conclusions
All these binoculars are “good glass” and would be suitable for replacing my aging Bushnells. I think the superior low light performance would provide at least thirty minutes of extra hunting time over the Bushnells at dusk. That could make the difference in seeing that big buck.
For the short walk to the blind or riding in the truck where weight is not so important, the power and brightness of the Minoltas are a great value.
The Swifts look well-made and are high performers, too. Their strengths are light weight and brightness. And their FOV is 50% wider than the Wind Rivers. At long distances, however, they suffer in comparison to the other more powerful binoculars.
I really liked the lightweight Steiners, especially the armor and lens cover package. There is nothing to fall off and lose, and no separate case to keep up with. The performance, while not up to the larger Minoltas or more expensive Swifts, is still solid.
While I rated the Wind Rivers low on several counts, they are still a good value at their street prices. For 10x50 power, they are much smaller than the Minoltas. And, they are backed by the good folks at Leupold in Oregon.
Ed Note: I wrote this article in 1997 and some of the models mentioned herein may no longer be available. However, the evaluation techniques described still apply.
I recently decided I needed to replace my aging binoculars, a pair of Bushnell Sportview 7x35 wide angle. I had long recognized their poor performance, particularly in the very early morning and late evening when the deer are moving. I wanted to get a more powerful pair of binoculars that offered low-light performance similar to my Leupold 3.5-10x50 riflescope.
I was able to borrow a variety of binoculars to test side-by-side, a method I heartily recommend. The four models shown below represent the lower cost models from their respective manufacturers. Table 1 shows a summary comparison of specifications.
Table 1: Binocular Summary
Manufacturer and Model / FOV1000 yd, ft / Eye Relief, mm / Weight, oz. / Street Price
[*]Minolta Standard XL 10x50 WA / 341 / 18 / 35 / $150[*]Wind River 10x50 / 275 / 16 / 28 / $200[*]Steiner Big Horn 9x40G / 300 / 20 / 26 / $400[*]Swift Audubon 8.5x44 ED / 430 / 15 / 29 / $450 [/list]
Minolta Standard XL 10x50 WA
The Minoltas are center-focus, BaK-4 porro prism binoculars. A right eyepiece diopter adjustment compensates for the user's difference in left and right eye acuity.
The Minoltas are covered with a thin slate gray rubber finish. They were the largest binoculars tested, weighing in about ½ lb more than the lightest.
Lenses are protected by individual covers. The eyepiece lens caps fit inside the eyecups, requiring the eyecups to be extended before the covers will fit. The Minoltas came with a thin, plain neck strap and a soft-side carrying case.
Wind River 10x50
The 10x models feature porro prisms and center focusing adjustments. A right eyepiece diopter adjustment compensates for the user's difference in left and right eye acuity.
The Wind Rivers were the cheapest looking of the tested binoculars. They reminded me of my old Bushnells. The soft black leatherette finish was bubbled in places. Accent lettering is gold.
However, for a 10x50, they are much smaller than the Minoltas. They are almost exactly the size of the Steiners while offering a more powerful objective.
Lenses are protected by individual covers. The eyepiece lens caps fit over the eyecups. The eyecups must be extended before the covers will fit. The Wind Rivers come with a thin nylon neck strap and soft-side cordura carrying case.
Wind River products feature a limited lifetime warranty.
Steiner Big Horn 9x40G
The 9x40 G "Big Horn" is a military/marine binocular. They would be considered a mid-grade model. Like all the Steiner binoculars, once individually focused to your eyes, they are focus-free.
The Steiners are covered with a thick green armoring decorated with gold accent lettering. Due to their construction, they are waterproof.
The Steiners do not come with a carrying case. Instead, a wide neck strap is fitted and a one-piece eyecup cover slides on it. The cover is large enough to fit over eyecups that are collapsed for glasses wearers. On the objective end, individual caps are attached to each lens barrels so they cannot be lost. They come with a 10 year warranty
Swift Audubon 8.5x44 ED
The Swifts are center-focus, porro prism binoculars. A right eyepiece diopter adjustment compensates for the user's difference in left and right eye acuity. They were the smallest binocular tested.
This Swift model was equipped with ED ("extra-low dispersion") glass. The longer the focal length, the more visible chromatic aberration is. ED glass has lower dispersion, so it reduces the amount of chromatic aberration.
They are the best-looking and smallest pair tested. A fine, hard-wrinkle finish is accented with a red stripe around the objective lenses. Accent lettering is gold.
The objective lenses are protected by individual covers, while the eyepieces share a cap that fits over the eyecups. The cover will fit over eyecups that are collapsed for glasses wearers.
The Swifts came with a foam padded neck strap and a soft-side carrying case. They have a lifetime warranty.
Test Procedures
I had never tested binoculars before so my first question was “How do I test binoculars?” I did an Internet search and came up with some good ideas (e.g., http://www.birdwatching.com/optics/binocsbwd95.html). Then I added additional ones as I thought of other issues I had experienced with optics. Since I am a glasses wearer, I also had to conduct some tests with and without glasses.
Most of the tests were conducted at ranges between 300 and 1000 yards. Low light evaluations were also made at shorter distances.
Test 1: Exit Pupil Examination
Take the binoculars and hold it at arms length with the objective lens (the lens that is furthest from your eye) facing away from you. You should see a small circle of light, called the exit pupil. Better quality binoculars will show a circle that is clear and easy to see. If the binoculars are of poor quality you may actually see a square area with shading outside of the square area around the edges of the lens.
None of the tested binoculars demonstrated any objective squareness. The Steiners were perfectly round, the Wind Rivers the next best, followed by the Swifts and Minoltas. With my old Bushnells, I could see the square with the shading around it.
Test 2: Low Light Evaluation
One way to immediately know if you are getting a good quality pair of binoculars is to look at them in low light conditions Try going to a store around dusk and look outside with the binoculars. However, if you're unable to go to a store at that time of day, look around in the store for a dark corner and try focusing different pairs of binoculars there. It is easier to see quality differences in binoculars in low light rather than in bright light.
I found this to be the hardest test to conduct. All these binoculars are so good that it has to be really late in the evening or early in the morning to observe their differences. At these times, the lighting conditions are changing rapidly, and, as a result, I spent several mornings and evenings trying to fairly evaluate the four.
I also found it was imperative to have the interpupillary distance (IPD) set correctly. If the IPD is too short, the binoculars will appear dark. Widening the IPD brightens the binoculars to a point.
I had always set the IPD by looking through the binoculars and adjusting until I had a good circle of view. Since each pair has a IPD scale on the hinge, I had my IPD measured so I could tell how accurate the scales were. Using the circle method for setting the IPD, I found I consistently set the distance less than the correct scale value for all the binoculars except the Steiners. For the testing, I set each pair to the correct IPD on the scale.
With its large exit pupil (44/8.5 = 5.2 mm), it should come as no surprise that the Swifts were the brightest. However, the advantage is small, and the power of the Minolta helps it to seem brighter at times. The Steiner has the smallest exit pupil, yet still outperforms the larger Wind Rivers.
Test 3: Distortion
Poor quality lenses in binoculars will result in some distortion. In order to try to find this, here is a simple exercise. When you are looking through the binoculars, focus on a subject that has straight lines. It can be either vertical, horizontal or both. For example, if you are looking out a window and there is a telephone pole, adjust the binoculars so the telephone pole is at the edge of the image. If the telephone pole seems distorted and seems to be leaning outward this is known as barrel distortion. If it seems to be leaning inward towards the center of the lens this is called pin-cushion distortion. While most binoculars have this to a certain extent, your goal here is to check for the degree of the distortion and determine what is acceptable for you.
This test was probably the least important to me so I spent less time with it. All the tested binoculars exhibit a small degree of barrel distortion. However, I thought they were all about the same, and it wasn’t noticeable. I did not observe pin-cushion in any of the binoculars.
Test 4: Edge Focus
Look through the binoculars and find a subject and make sure it is dead center in the middle of the lens. Focus on it and then move the binoculars slightly so the subject that was in sharp focus is now at a far edge of the binoculars. Check to make sure if it is as sharp as it was when it was in the center of the binoculars. Remember any binoculars may exhibit some of these problems to some degree, so your purpose here is to compare one pair against the other to determine what is best for you.
For this test, I judged the distance from the edge of the lens in which the target lost focus. I found the Steiner to have exceptional edge clarity, right to the very edge. The Wind River was the second best. Next were the Minoltas, followed by the Swifts. At the extreme edge, these last two had about the same degree of fuzziness. The results of this test surprised me the most. The Swifts lost focus very early and were distinctly worse than the Steiners.
Test 5: Field of View
Field-of-view (FOV) is important for viewing moving game. A wide FOV will help the user locate the game in the binocular. This test was made to check the relative FOV of the binoculars. By observing objects in the distance, the binoculars were rated for FOV.
As expected the Swifts, the lowest power binocular tested, had the largest FOV. The Minoltas were the next best, and the Steiners were next. The Wind River had the most limited FOV.
This test confirmed the relative ranking expected according to the manufacturer’s claims. The Minoltas, one of the most powerful binoculars tested, were outstanding performers
Test 6: Field-of-View with Glasses
With eyeglasses, FOV may be reduced due to the eye relief and alignment problems. To check for problems, the relative FOV test was repeated with my glasses on.
In this test, the Minoltas had the widest FOV, followed by the Swifts, the Steiners, and the Wind Rivers.
Test 7: Low-Angle Sun
I created this test to simulate those late mornings and late afternoons when you may find yourself looking into the low-angle sun. The test consisted of positioning the binocular so that the sun was just out of the top of the lens and then observing any glare on the lens.
The Minoltas were superb in this test, showing absolutely no glare. The Swifts showed a rosy tint on the top portion of the lens. The Steiners were the most distracting with what appeared to be an internal reflection on the bottom portion of the lens. Cloudy, hazy weather prohibited testing the Wind River for sun glare.
Test 8: Ergonomics
Each binocular had its unique ergonomics characteristics. The Minoltas were the largest and heaviest overall. They also have unusually large eyecups, 1.675” diameter compared to 1.375” for all others.
The Swifts are lightweight, compact, and the wrinkle finish has a good feel. The center-focus knob is wide and has a soft rubber coating.
The Steiners are also lightweight, and the rubber armor coating with built-in lens caps make a good package. Once the focus was set, I didn’t have to change it. The Steiners also had the widest neck strap, but the hard plastic adjustment buckle landed right on the back of my neck.
The Wind Rivers feel comfortable in your hands. The center-focus knob is actually wider than the Swift’s, but has a hard rubber coating. Some slop was felt in the focusing adjustments.
Test 9: Other Impressions
Another "test" I conducted was to get the input of others and how they rated the models. My wife accompanied me one afternoon for some bright daylight testing. She liked the Swift for their field of view, clarity, and light weight. My oldest son liked the clarity of the Steiners best and the Minoltas next. The younger son favored the Swifts and then rated the Minoltas second best.
Conclusions
All these binoculars are “good glass” and would be suitable for replacing my aging Bushnells. I think the superior low light performance would provide at least thirty minutes of extra hunting time over the Bushnells at dusk. That could make the difference in seeing that big buck.
For the short walk to the blind or riding in the truck where weight is not so important, the power and brightness of the Minoltas are a great value.
The Swifts look well-made and are high performers, too. Their strengths are light weight and brightness. And their FOV is 50% wider than the Wind Rivers. At long distances, however, they suffer in comparison to the other more powerful binoculars.
I really liked the lightweight Steiners, especially the armor and lens cover package. There is nothing to fall off and lose, and no separate case to keep up with. The performance, while not up to the larger Minoltas or more expensive Swifts, is still solid.
While I rated the Wind Rivers low on several counts, they are still a good value at their street prices. For 10x50 power, they are much smaller than the Minoltas. And, they are backed by the good folks at Leupold in Oregon.