Saving Steps with Optics

Saving Steps with Optics

I am trying my best age gracefully, and one of those realities I face is that I have to make some compromises in my photographic outings. A 10 mile hike with an 85 pound backpack was a common thing in my youth. Now, I use every bit of technology to save me all those steps that I possibly can, and do what I must to preserve my strength and stamina for the most important parts of my creative life. Curiously enough, one of the most useful tools in this regard has become an effective pair of binoculars. I'm more than happy to look and study from a distance before I haul my gear way over there only to find out there's not much of interest. In fact, I've found a good pair of binoculars has made my photography considerably more efficient because I waste far less time exploring places that ultimately are unproductive.

Because I wear glasses to correct astigmatism, I need to wear my glasses when using my binoculars. This is a problem with most binoculars because of the way this increases the distance between my eyeball and the optics of the binocular. This extra distance reduces one's field of view — sort of like looking through a straw. Removing my glasses for use with typical binoculars leaves me seeing a fuzzy world. Fortunately, there is an answer.

I learned about the optical measurement called "eye relief." From Wikipedia: The eye relief of an optical instrument (such as a telescope, a microscope, or binoculars) is the distance from the last surface of an eyepiece at which the user's eye can obtain the full viewing angle. The farther the eye relief distance, the more there is room for one's eyeglasses to remain in place without losing some of the field of view.

Many binoculars have an eye relief in the 12 to 15 mm range. For eyeglass wearers, eye relief in the 20 to 25 mm range is much more practical. As one of the primary considerations in my research, I discovered one has to shop more diligently to find devices that meet this criteria. I found two that have quickly become some of my most valuable tools when I'm in the field.

First, I always carry in my camera bag a slick little, lightweight monocular manufactured by Carson. It's a 7-power by 32mm device that is very sharp, with excellent contrast, and fully multi-coated lenses. Most importantly for us eyeglass wearers, it has a 19 mm eye relief — not perfect, but comfortable. Additionally, it includes a handy tripod mount thread which I find incredibly useful to stabilize my view when used in combination with either my monopod or a simple walking stick.

Where weight is less of a concern, I use a great pair of Montana binoculars (now owned by Meade) that have a 20mm eye relief. I had to search high and low to find binoculars with long eye relief, but what a difference it makes! I absolutely love these binoculars because of this feature. (Carson makes a similar model with a 22mm eye relief, but I haven't use them myself so I can't report on them from experience.)

If you wear glasses and have been frustrated with binoculars, try searching for ones with longer eye relief and you'll be amazed how much more you enjoy using them.

Comments

[Pat Cooney]

I too am "trying my best TO age gracefully."

I too have significant astigmatism and am VERY aware of the eye-relief issue.

Keep up the good work, Brooks.

--Pat Cooney

[David Blanchard]

The last time I bought binoculars I had reasonably good vision. Time has taken a toll. Thanks for the insightful overview.