Our test team utilizes a combination of measured and observed tests, in both a test environment and the field, to do the most comprehensive evaluations of every pair of binoculars we handle so that we can confidently recommend the best pair of binoculars for your intended use. We’ve designed our tests and procedures to evaluate 6 major metrics and weighted them based on their importance. We separated those metrics into a variety of testing procedures that measured and ranked clarity, brightness, comfort, field of view, ease of adjustment, and close focus range, with the first two metrics accounting for more than half of the overall score of each pair of binoculars. If you are more interested in what qualities to look for versus our testing procedures, check out How To Choose Binoculars For Your Needs and Budget.
Clarity
Lens quality has a massive impact on clarity. Still, it claims about the diamond-like quality of one’s glass, or the lens’s premium price, are far from objective, so our product testers performed a more standardized test to compare the clarity between each pair of binos more closely. This was tested using an ISO 12233 chart, the industry standard for measuring digital still imagery. By viewing the same chart through each pair, we were able to evaluate the differences between models.
We then viewed the ISO chart through each pair of binoculars at a specific distance and noted how well we could read the different zones of the chart. The best and clearest pairs allowed us to see clear and crisp zones. Additionally, we made note of any other abnormalities, such as chromatic aberration and color fringing.
With some pairs, we started to notice blurriness, color fringing, and aberrations around the edges, as well as an overall haze.
We also repeated this test using a more realistic scenario. We purchased two model birds (that we affectionately named Garry the goldfinch and Barry the bluebird) and placed them in a tree. We then observed the birds through each pair of binoculars. We mounted the binoculars on a tripod for this test to ensure each pair was in the exact same position. We then took photos through each pair of binoculars so we could more easily make side-by-side comparisons.
Brightness
Our test team measured brightness through observation, as well as lab-controlled tests. For observation, we took each model out for morning and evening sessions, at the same exact time to ensure the viewing conditions were the same. Any difference in the lighting conditions has a dramatic effect on these tests, so we made a lot of comparisons, and repeated these tests. Our team took notes about the brightness for each model, which included additional information about abnormalities-similar to our clarity tests.
In our controlled testing, we set up a 3500k light at 40% completely flush to the lenses of binoculars at a fixed distance on a platform, the latter designed to ensure each one was properly centered. We then measured the light at the eye-piece with a light sensor.
Additionally, our team awarded a very lightly weighted percentage of points for exit pupil size, as this has an impact on the ability to let light enter one’s eye.
Comfort
For our comfort metric, we tried to reduce subjectivity by having multiple testers evaluate griping and holding each pair of binos, as well as eye cup comfort, and the overall nature of the included neck straps. While larger binoculars offered greater clarity and brightness, their size and weight often hurt ergonomics. Cheaper pairs frequently used cheaper materials, which often meant more rigid plastics, versus more rubberized textures and softer eye cups of better models. Weighted scores were combined and averaged for an overall comfort score.
Field of View
For our FOV metric, we measured the field of view at 800 yards, as that is the max range that the terrain of our field testing allowed us to do. We then calculated the viewing angle at the 800-yard distance and converted it to the field of view in feet at 1000 yards. Our field of view measurements, with one exception being within 3% of the manufacturer specifications, all underperformed manufacturer specifications by an average 13%.
Ease of Adjustment
A clunky pair of binos that is difficult to adjust is more likely to get left in a pack, car, or just stay at home. So we evaluated the ease with which each pair of binos focused, and adjusted for proper eye relief. We tested by focusing on an object at a fixed distance a few hundred feet away and evaluated the ease of rotating knobs. We counted the number of rotations it took to adjust from a close object to a far object at a fixed distance. We also evaluated how well eyepieces allowed us to attain and even lock the eye relief distance as well as whether or not the diopters held a position, locked, or moved too freely. Models varied quite a bit, with some models feeling like they had wooden cogs inside and others feeling more like a Swiss watch.
Close Focus Range
We measured close focus range with a realistic birding scenario. We set up our model bird in a well-lit area, then increased the focus to the max. We then walked back the focus until the model was in the best focus possible. Once each pair of binos was perfectly focused, we precisely measured the distance between the observer and the bird. Our testing revealed a wide range of performances, with some models performing better than the manufacturer-stated specifications, while most models performed worse.
Conclusion
Whether it is your first pair, or you are interested in upgrading your optics, there’s a lot to consider when trying to choose binoculars. We hope our testing procedures, and comprehensive review is enough to help you choose the level of performance, within your budget.
