Birders form a very special bond with their binoculars. Those who don't know any better would call it a psychosis, but for anyone who has spend a lot of time peering through the same lenses in search of dreamed-of life birds understands what I mean. The binos we use to take our life list from 0 to 400 are closer to us than most of our friends; when they take us from 400 to 700+, our spouses make us begin marriage counseling.
Nevertheless, every time we flip through the newest birding magazines, the ads from Leica and Swarovski start us thinking adulterous thoughts of disloyalty, of abandoning our loyal optical partner for some salacious German vixen. Our hearts beat faster, our faces flush, our eyes wander lovingly over the curves on the barrels, the ergonomic teasings of the rubber molding. The spec list makes our knees tremble with such seductive phrases as "nitrogen-filled," "hydrophobic coating," and (most effervescent of all) "interpupillary distance." Before too long we have given ourselves heart and soul to the fantasy of standing one day in some tropical rain forest with our very own sexy Ultravids lovingly caressing us around the neck, as the local avians serenade with their exotic sonatas.
But we eventually sigh our "If only" and turn the page, but not without a guilty glance at our old stand-by sitting attentively on the shelf next to us.
Saturday, November 10, 2007
Thursday, November 8, 2007
The Basics of Buying Binoculars
Thinking about upgrading your optics? Researching your options with binoculars can be a daunting task, but the basics are all you really need to know in order to make the correct choice.
Price range: There are three cost ranges of binoculars: low, medium, and high. In general with binoculars, you get what you pay for; the best quality costs the most. Zeiss, Leica, Swarovski, and Brunton all have high-end optics that retail around $1500--well out of the price range for many birders. Rest assured, however, that a thoroughly enjoyable and birding career can be had without Zeiss and Leica. If this is your first pair of binoculars for birding, or your first upgrade, plan on spending at least $200 to avoid being continually frustrated with poor images.
Magnification: This is fairly straightforward: magnification is the first number written on the binoculars. A pair of 10x40 binoculars magnifies an object 10 times (10x). The greater the magnification, the closer the image appears in the binoculars. Generally, the greater the magnification, the greater the price and weight of the binoculars. See "Field of View" for more on selecting the proper magnification.
Light Transmission: Most people assume that binos with greater magnification inevitably produce better images, and are therefore better binos. But this is not necessarily true. Higher magnification always produces bigger images, but also has a lower light transmission. This means generally that the greater the magnification, the darker the image.
Light transmission is determined by the amount of light exiting the "eyeball end" of the binos. This amount of light, called the exit pupil size, is calculated by dividing the size of the objective lens (the second number written on the binoculars) by the magnification. This means that 10x40mm binos have an exit pupil size of 4mm (40 divided by 10); 7x35 binos have an exit pupil size of 5mm. Obviously, the larger the exit pupil size, the greater the light transmitted, and therefore the brighter the image.
So, greater magnification gives bigger images, but lower magnification tends to give better light transmission. Keep in mind that light transmission is a concern only in low-light birding situations, such as birding at dusk for owls or at dawn for rails. In ordinary daylight, binoculars with the same quality lenses will be equally bright, despite differences in magnification and objective lens size.
Field of View: Field-of-view is simply the width of vision seen through the binoculars. This is generally expressed at 1000 yards, which isn't that helpful since field-of-view matters at close range. To better understand field-of-view, move the decimal point two digits to the left: a field-of-view of 350 feet at 1000 yards means a field-of-view of 3.5 feet at 10 yards. At 10 yards, field-of-view becomes a vital factor in how quickly a birder can find and follow birds, especially when they are in thick brush.
Field-of-view is most closely related to magnification. The greater the magnification, the smaller the field-of-view. For this reason, most Eastern birders use 7x and 8x, giving them a larger field-of-view to bird effectively in the denser foliage of the East. In the West, where distances are greater and the foliage is sparser, 10x and even 12x binoculars are the norm--especially for hawk watching and shorebirding.
Close Focus: Many birders are also becoming interested in butterflies, which require very close-focusing capabilities. Close focus is also important for watching birds at window feeders. There are several brands of binos that feature extremely close focus (around 5 feet). For birding purposes, get a close-focus of no greater than 10 feet for maximized use with small brush-loving birds like sparrows and warblers.
General Advice:
Price range: There are three cost ranges of binoculars: low, medium, and high. In general with binoculars, you get what you pay for; the best quality costs the most. Zeiss, Leica, Swarovski, and Brunton all have high-end optics that retail around $1500--well out of the price range for many birders. Rest assured, however, that a thoroughly enjoyable and birding career can be had without Zeiss and Leica. If this is your first pair of binoculars for birding, or your first upgrade, plan on spending at least $200 to avoid being continually frustrated with poor images.
Magnification: This is fairly straightforward: magnification is the first number written on the binoculars. A pair of 10x40 binoculars magnifies an object 10 times (10x). The greater the magnification, the closer the image appears in the binoculars. Generally, the greater the magnification, the greater the price and weight of the binoculars. See "Field of View" for more on selecting the proper magnification.
Light Transmission: Most people assume that binos with greater magnification inevitably produce better images, and are therefore better binos. But this is not necessarily true. Higher magnification always produces bigger images, but also has a lower light transmission. This means generally that the greater the magnification, the darker the image.
Light transmission is determined by the amount of light exiting the "eyeball end" of the binos. This amount of light, called the exit pupil size, is calculated by dividing the size of the objective lens (the second number written on the binoculars) by the magnification. This means that 10x40mm binos have an exit pupil size of 4mm (40 divided by 10); 7x35 binos have an exit pupil size of 5mm. Obviously, the larger the exit pupil size, the greater the light transmitted, and therefore the brighter the image.
So, greater magnification gives bigger images, but lower magnification tends to give better light transmission. Keep in mind that light transmission is a concern only in low-light birding situations, such as birding at dusk for owls or at dawn for rails. In ordinary daylight, binoculars with the same quality lenses will be equally bright, despite differences in magnification and objective lens size.
Field of View: Field-of-view is simply the width of vision seen through the binoculars. This is generally expressed at 1000 yards, which isn't that helpful since field-of-view matters at close range. To better understand field-of-view, move the decimal point two digits to the left: a field-of-view of 350 feet at 1000 yards means a field-of-view of 3.5 feet at 10 yards. At 10 yards, field-of-view becomes a vital factor in how quickly a birder can find and follow birds, especially when they are in thick brush.
Field-of-view is most closely related to magnification. The greater the magnification, the smaller the field-of-view. For this reason, most Eastern birders use 7x and 8x, giving them a larger field-of-view to bird effectively in the denser foliage of the East. In the West, where distances are greater and the foliage is sparser, 10x and even 12x binoculars are the norm--especially for hawk watching and shorebirding.
Close Focus: Many birders are also becoming interested in butterflies, which require very close-focusing capabilities. Close focus is also important for watching birds at window feeders. There are several brands of binos that feature extremely close focus (around 5 feet). For birding purposes, get a close-focus of no greater than 10 feet for maximized use with small brush-loving birds like sparrows and warblers.
General Advice:
- Consider what type of birding situation you will be in the most: dense brush or open spaces (Eastern U.S. or Western)? This will determine the magnification you need.
- Will you be doing a lot of low-light birding? If so, purchase a bino with a larger exit pupil size for brighter images. (By the way, the lens coating on more expensive binos also increases brightness.)
- Do you need extreme close-focusing capabilities?
- Once you determine your magnification, light transmission, and close focus needs, go to a store that sells binos with these specs and test them by taking them outside (with their permission) and "field-testing" them. While you're there, try out some high-end binos as well to get a feel for their quality. You should also experiment with different magnifications.
- Watch out for gimmicks and bargains. Quality binoculars cost money, and don't also take pictures, walk the dog, or make coffee. (Although Leica does have a very excellent pair of range-finding binos.)
- Buy the very best binos you can afford. You will have these for a very long time and become very attached to them. Buyer's remorse is painfully intense when the possible life bird flies unidentified into the distance because you were overly frugal.
Wednesday, June 20, 2007
Night Visitor
When I arrived home tonight, I was surprised to find this Columbia Spotted Frog on my doorstep. The warmth and wet must have brought it wandering out of the nearby wetland.
Notice the yellowish stripe that runs from the tip of its snout under its eye--a sure field mark for this species.
(Yes, the obsession runs beyond just birds.)
Confession at the End of June
In Bozeman, June is coming to an end in its typical fashion: incredibly long days, warm nights, evening thunderstorms, and juvenile birds. American Robins are in their second brood, and the ugly faces of adolescent Tree Swallows line the power lines like gangs of miscreant, loitering teenagers. Short-tailed magpies are increasing in abundance; like Pinocchio, some day they will be real, but only when they've squawked enough lies to make their tails grow to length.
Most indictative of the end of June for me is my mounting wanderlust. I long for the Texas birds I saw in March, for the pebbly beaches of Alaska, or the unexperienced canyons of Arizona. The oft-quoted mantra of "Every bird is a good bird" is indeed virtuous; and I strive to be an righteous birder. But the reality is that the end of June always means jaded discontent with my local patch.
It is likely that this is a result of my typical American materialism, a more soul-threatening condition than being bored with House Wrens. But, when I'm philosophical, I chalk it us as an innate awareness of my transient mortality--so many birds to see and so little time. The whimsical dreaming of other unseen birds approaches the state of psychosis as the first of July draws near. My wife knows well what that faraway glint in my eye means; she insists on driving more, never leaves the kid alone with me for too long, keeps me away from the hot stove. She understands that this too will pass, as the summer always does.
She also understands that this longing for More actually flows from a deep appreciation for what my local patch has taught me. The countless hours of pleasure spent with these so-familiar birds and the knowledge of all that I haven't seen combine to create this annual soul-ache. And this year an early July trip to Alaska will be the Balm of Gilead my soul needs.
Most indictative of the end of June for me is my mounting wanderlust. I long for the Texas birds I saw in March, for the pebbly beaches of Alaska, or the unexperienced canyons of Arizona. The oft-quoted mantra of "Every bird is a good bird" is indeed virtuous; and I strive to be an righteous birder. But the reality is that the end of June always means jaded discontent with my local patch.
It is likely that this is a result of my typical American materialism, a more soul-threatening condition than being bored with House Wrens. But, when I'm philosophical, I chalk it us as an innate awareness of my transient mortality--so many birds to see and so little time. The whimsical dreaming of other unseen birds approaches the state of psychosis as the first of July draws near. My wife knows well what that faraway glint in my eye means; she insists on driving more, never leaves the kid alone with me for too long, keeps me away from the hot stove. She understands that this too will pass, as the summer always does.
She also understands that this longing for More actually flows from a deep appreciation for what my local patch has taught me. The countless hours of pleasure spent with these so-familiar birds and the knowledge of all that I haven't seen combine to create this annual soul-ache. And this year an early July trip to Alaska will be the Balm of Gilead my soul needs.
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