Archive-name: birds-faq/optics Last-modified: 8 August 1994 Posting-frequency: monthly Frequently Asked Questions about Optics for Birding August 1994 | This is the list of Frequently Asked Questions (FAQ) about optics for | birding. This FAQ started as a monthly posting to the Internet news | group rec.birds. I now post it monthly to rec.birds and the BIRDCHAT | mailing list on or about the 15th of the month. | | Send any comments, suggestions, or additions to Ed Matthews | . I do not receive rec.birds or BIRDCHAT, so I don't see discussion on the net. Please forward any appropriate mail to me. Notes ===== 1. Hey, you guys missed some typos last month! 2. Can somebody send me a discussion of various kinds of lens glass: e.g., ED, fluorite, etc. 3. Can anyone contribute a discussion of the various prisms? Porro vs Roof, etc. Summary of Changes Since Last Publication ========================================= [As always, change bars '|' mark significant changes] 0. Minor edits. 0. Now posted to BIRDCHAT on monthly basis. 2.15 Hopefully now written in more readable English :) 2.17 New info on finding birds quickly 5. New info on National Camera Exchange Table of Contents ================= 1. General Advice 2. Common Questions About Optics 2.1 What does 7x35 mean? 2.2 How do I chose a magnification level? 2.3 What is field-of-view? 2.4 What about rubber armoring? 2.5 Can I use binoculars and scopes with eyeglasses? 2.6 What is eye relief? 2.7 How do I judge comparable binoculars? 2.8 What about fixed versus zoom eyepieces for scopes? 2.9 What about 45 degree eyepieces for scopes? 2.10 Can I take pictures through a scope? 2.11 How close should I be able to focus? 2.12 Which inexpensive binoculars would you recommend to a beginner? 2.13 What does the endorsement of the National Audubon Society mean? 2.14 How should I clean my lenses? 2.15 What should I know about lens coatings? 2.16 How can I hold my binoculars steady? 2.17 How can I find birds quickly with my binoculars? 2.18 What factors affect brightness in optical instruments? 2.19 What other factors should I consider in buying binoculars? 3. Supports 3.1 Tripods 3.2 Monopods 3.3 Finnsticks 3.4 Shoulder Stocks 3.5 Window Mounts 4. Ratings 4.1 Better View Desired (Scopes and Binoculars -- November 1993) 4.2 Living Bird (Binoculars -- Autumn 1992) 4.3 British Birds (Owner Survey, Binoculars and Scopes, July 1991) 4.4 Living Bird Quarterly (Scopes -- Autumn 1990) 5. Sources for Optical Equipment 6. Useful Reference Material 7. Contributors 1. General Advice ================= Don't buy any optical equipment without first field testing it, especially if you wear glasses. Go to a popular birding spot and ask to try various scopes and tripods. This is the only way to determine individual preferences such as weight, balance, and desirable magnification level. Owners of most tripod brands report loose parts and some report rust. Tripods, like any other equipment with moving parts, require periodic tightening and cleaning. A good strap on a scope or binoculars increases comfort dramatically. The new breed of neoprene straps from OP/TECH come highly recommended. They are available from most optics merchants and camera shops. 2. Common Questions About Optics ================================ 2.1 What does 7x35 mean? The first number (7) is the magnification (or power). The second (35) is the size in millimeters of the objective lens (or aperture). The objective lens is the large lens through which the light first enters the binocular or scope. Objective lens size is a key factor in how much light enters the instrument. To determine the relative brightness of an instrument, divide the objective lens size by the magnification (e.g., 35mm/7 = 5mm). Optical instruments cease to be brighter when this measure, called the exit pupil, exceeds the size of your pupil. Apparently, as you age, your pupil does not dilate as much as when you are younger. By age 40, your pupil dilates to a maximum of about 5mm. Buying binoculars with a larger exit pupil is a waste of money. If exit pupil were the only factor in brightness, your choice would be easy. However, the quality of the glass and its coatings (q.v.) play a large part in determining brightness. You will find that good 10x40 (4mm exit pupil) binoculars are generally brighter than cheap 7x35 (5mm exit pupil) binoculars. Birders who try to see pelagic birds on an active ocean find their binoculars move around a lot with respect to their eyes, especially if they wear eyeglasses. An over large exit pupil helps keep a bird in view as they bounce around on the tossing deck, with the binoculars in one hand and the other hand holding onto the boat itself. 2.2 How do I chose a magnification level? The lower the magnification (power), the shorter the effective range of the instrument. As a payoff, you get a brighter image and a wider field-of-view. The higher the power, the harder the instrument is to hold steady, the less bright the image, and the narrower the field-of-view (q.v.). For binoculars, common magnification levels are 7x, 8x, and 10x. Good quality optics are generally more important than magnification level. For scopes, the most popular range is between 20x and 40x. Distortion from heat shimmer becomes a big factor over 40x. Lower than 20x limits the useful range of the scope. The power of an instrument is the focal length of the main objective divided by the focal length of the eyepiece. For instance, a scope with a main objective of 900mm focal length and eyepiece of 30mm focal length is 30x (900/30). In very simplistic terms, the focal length of a simple, thin lens is the distance from the lens that it focuses the object. For example, a lens with a 30mm focal length would focus its image 30mm behind the lens. 2.3 What is field-of-view? Binoculars typically have a label that expresses field-of-view (FOV) in degrees and/or width at a given distance. Expressed in degrees, FOV means that portion of a circle (360 degrees) visible at a certain distance. In the US, we calculate FOV at a distance of 1000 yards (923m). Typical FOV at 1000 yards ranges between 5 and 8.5 degrees, which corresponds to a FOV range of 263 to 446 feet (81 - 137m). [How is FOV expressed in countries other than the US?] In many cases, the actual FOV may be markedly different than what the manufacturer says it is. To compare the FOV of binoculars with different magnification levels, compute the "apparent FOV". This is the actual FOV times the magnification. Typical values range from 45 to 75 degrees with most being between 50 and 65. Other things being equal, wider FOV is generally better than narrower | FOV for helping you find birds more easily. Of course, other things seldom are equal, and you generally must pay for wide FOV some other way: lower resolution, lower magnification, less eye relief, greater weight, or higher cost. 2.4 What about rubber armoring? Binoculars and scopes are sometimes clad in rubber -- this is known as rubber armoring. Rubber armoring provides protection against corrosion and dirt, helps cushion blows to the instrument, and gives a less slippery surface to grip. Armoring adds a little weight and may require maintenance with a rubber preservative. Many feel rubber preservatives leave a greasy feeling. 2.5 Can I use binoculars and scopes with eyeglasses? You certainly can; however, DO NOT BUY BINOCULARS OR SCOPES WITHOUT TESTING THEM WITH YOUR GLASSES. Some people like to use their binoculars without their glasses. There is no harm in this. However, if you have astigmatism, you need your glasses to help you focus, even with the binoculars (which only increase magnification). People who wear eyeglasses often have trouble with scopes and binoculars. Try several models with your glasses. The critical factor if you wear glasses is eye relief (q.v.). Look for eye relief of at least 15mm. Since eye relief is a property of eyepiece design, you cannot change the eye relief of binoculars. Several scopes offer optional long-relief eyepieces -- Kowa's are excellent. One exception is the Bausch & Lomb Elite scopes with fixed lenses; they come with long-relief eyepieces as standard equipment. 2.6 What is eye relief? Eye relief is the distance between the eyepiece and your cornea when you are seeing the full illuminated circle of the image, the sensation of "looking through" the scope or binoculars. You can determine empirically the eye relief of binoculars by holding them steady in a shaded location pointed at a bright sky or surface. Hold white paper behind the eyepiece and you will see a bright disc of light on the paper. This is the exit pupil as discussed earlier. Move the paper until the disc is sharpest; this is the precise location of the exit pupil in space. The distance between the eyepiece and the paper is the eye relief. If you wear glasses, eye relief is critical since you must have enough room to get your glasses between the lens and the focal plane. Even if you do not wear glasses, a reasonable amount of eye relief helps keep the instrument far enough from the eye for comfort. However, high eye relief designs may give non-eyeglass wearers the sensation that they need to move their eyes far back from the eyepiece. In general, shorter focal length eyepieces have shorter eye relief. High eye relief designs are usually more expensive. Also, higher magnification generally means less eye relief; scope users may have noticed this in changing eyepieces. Many eyepieces in wide-angle binoculars have low eye relief as a consequence of their design, something to remember and test if you are considering buying a wide-angle binocular. The ABA catalogs (q.v.) are good about listing eye relief figures for most eyepieces and state what they consider minimum. Celestron [Vixen in Europe] (and perhaps other astronomically oriented) scopes have optional Barlow lenses that may be of interest to eyeglass wearers. A Barlow lens is a long metal tube that attaches instead of the eyepiece. The eyepiece goes onto this tube, thus extending the physical length of the scope and effectively increasing the focal length of the objective lens. The beauty of the Barlow lens is that it increases power (about 2x) while letting you continue to use the same eyepiece with which you are comfortable, a big bonus for eyeglasses wearers. A couple of readers recommend the Barlows from Astrophysics. Drawbacks are that the overall length of the scope is increased, increasing the chances of damage in the field and making the scope a bit more awkward. Barlow lenses are not very common, nor are they suitable for quick changes in the field. Still, in a fixed setting such as nest watching, the fact you can double the power and preserve the eye relief is significant. Also, several scope manufacturers offer long eye relief eyepieces by various names. Celestron/Vixen calls their 20mm eye relief eyepieces LV (Long View). 2.7 How do I judge comparable binoculars? When judging binoculars, you should know what properties the power and aperture (e.g., 7x50) fix, as opposed to other parameters that are the consequence of good design (e.g., long eye relief). If you know the power and aperture, the following are fixed, and the most expensive pair of that type will have the same value as an inexpensive pair: Exit pupil diameter or "apparent brightness" Depth of field, i.e., range in which objects appear in focus at given distance Faintest STARS visible, determined by aperture only (indep. of power) Optical quality and design affect: Eye relief (tends to be longer in lower power binocs) Image contrast (because of number and quality of coated surfaces) Apparent field of view (can't be large if eye relief is long) Image sharpness across field (harder in wide field binocs) Closest focus (tends to be closer in low power binocs) Here are several examples: 7x35's are about as "bright" as 8x40's. Two 7x50's could have very different eye relief. If one pair has a wide apparent field, it probably has shorter eye relief. A large pair of 20x70's will have a less bright image than a small pair of 8x32's. That same 20x70 probably does not focus as close as the 8x32. 2.8 What about fixed versus zoom eyepieces for scopes? Fixed magnification eyepieces tend to give a crisper and brighter image. Zooms can be useful, but unless you spend a lot of money, they can be of lesser quality than fixed lenses. Some birders prefer interchangeable fixed lenses (e.g., a 25x lens and a 40x lens) to a zoom. Zooms on the expensive scopes (e.g., Kowa) are excellent. 2.9 What about 45 degree eyepieces for scopes? They are not hard to use when you get used to them and are preferable for watching flying birds, especially migrating raptors. If you're tall, you can use a slightly shorter tripod. If you're short, the lower scope gives more opportunity for somebody to step in your way. A drawback is that the eyepiece is angled up into the rain and blowing dust. 2.10 Can I take pictures through a scope? General consensus is that if you want to take professional pictures, don't use your scope. It requires a really steady (heavy) tripod and the combo of scope and camera is heavy and awkward. Focusing is difficult and close focusing is not generally possible. Scopes usually have a fixed, small aperture (typically f11). This means that you must adjust exposures by varying the shutter speed. With a small aperture, and a fast enough shutter speed to keep the bird from blurring, you must use fast film, even in bright sun. In early morning and late evening, or in shady woods, you simply won't have enough light to take a good picture. Some scope/camera combinations also have problems with vignetting: the rim of the scope is visible in the picture as a dark, fuzzy ring around the edge. [Paraphrased from the Canon EOS FAQ on rec.photo by Bob Atkins] In general, scopes are too slow and their focal lengths are too long. The longer the focal length, the steadier you must hold the lens and the more atmospheric effects will degrade the image. The only scopes capable of yielding high quality images are the fast, short focal length, apochromatic refractors. For example, TeleVue makes a 500mm f5 apochromatic telescope using Fluorite lens elements. It makes a very good lens (manual focus, fixed aperture), but costs US$1700, weighs 10lbs+ (4.5k+) and is about 36" (92cm) long. While not easy, you can use it in the field with a heavy tripod. Its performance as a lens is similar to the best telephoto lenses; however, it has several drawbacks. It has no autofocus; you cannot stop it down; and it is big and heavy. 2.11 How close should I be able to focus? [Paraphrased from _The Complete Birder_, Houghton Mifflin, Boston, 1988, by Jack Connor] Binoculars with close-focus are essential for woodland birding. You can visually separate several problematic pairs of small birds only at close range: Carolina and Black-capped Chickadees; Sedge and Marsh Wrens; Mourning and Connecticut Warblers; Le Conte's and Sharp-tailed Sparrows; Cassin's and Botterei's Sparrows; and many others. Fortunately, you can test close-focus in a store. Find the closest spot on the floor you can see sharply through the binoculars, then count your paces as you walk to it. For an accurate test, first adjust the dioptric-compensation ring for the difference in strengths of your two eyes. Without first doing this, your test will be inaccurate. A close-focus range of 15 to 18 feet (5 to 5.5m) is the least you should accept. If you like chasing sparrows and warblers, you'll be happier with a minimum range of about 10 feet (3m). Depending on your eyes, you can find binoculars with close-focus ranges down to 6 feet (2m). 2.12 Which inexpensive binoculars would you recommend to a beginner? Many people consider the Bushnell Birder 7x35 a great buy at US$75 or under. 2.13 What does the endorsement of the National Audubon Society mean? The NAS has licensed their logo to certain manufacturers and the logo appears on certain optical products. The appearance of the logo does not constitute any endorsement by NAS. The logo presumably indicates that the product is targetted at birders; however, it does not mean that it is any better than competing products from other manufacturers. 2.14 How should I clean my lenses? [From a Celestron manual:] "Always determine whether or not your telescope needs cleaning. Specks of dust or pieces of lint do not impair the visual or photographic performance of your telescope, but excessive cleaning can cause small scratches which harm performance more than lint or dust. These scratches cause light scattering, which is VERY harmful to optical performance. Professional telescopes used nightly, only need cleaning every six months or so." A good cleaning solution is a mixture of isopropypyl alcohol and distilled water with a few drops of biodegradable washing detergent. Do not use breath or saliva. Cotton balls of natural cotton are best. Never clean in circles to prevent making scratches all over the optics. Never rub or apply pressure! Use fresh cotton balls often. Go from the center to the edge of the lens; take another piece of cotton and repeat! To avoid frequent cleanings, always store your lens with the caps on. 2.15 What should I know about lens coatings? Low-reflection coatings increase the light transmitted through | binoculars by increasing contrast, reducing glare, and eliminating | reflections. For best results, all glass surfaces where the beam of light moves from air into glass or from glass into air should be coated. Cheap binoculars sometimes only have coatings on the outside surfaces, in an attempt to impress and confuse the gullible buyer. The best coatings are called "multi-coatings", or something similar; they are better simply because a multi-coated surface reflects less | light than one with a conventional coating. You can notice the | difference between single- and multi-coatings particularly when viewing birds in shade when the field of view also includes brightly lit objects (i.e., extreme contrast). It is hard to tell what surfaces of a binocular are coated, and with what kind of coatings, just by looking at them. For this reason alone, you should buy from a well-respected manufacturer and from a reputable dealer. 2.16 How can I hold my binoculars steady? [Jay Freeman offers this tip in Ronnie Kon's Purchasing Amateur Telescopes FAQ on sci.astro.] Most people hold a binocular with one hand on each side of the body -- roughly where the prisms are. The hands are directly left and right of the center of gravity of the instrument. For most people, there is a better position. Hold the binocular as described above. Slide your hands toward your face, until only your pinky and ring fingers (third and fourth) are curled around the back end of the binocular body. The binocular will feel a little nose-heavy, because you are supporting it behind its center of gravity. Curl each thumb up as if you were making a fist, and flex your hands so that the second bone in from the tip of your thumb is pressed against your cheekbone. Finally, curl the first and middle fingers of each hand around the corresponding binocular eyepiece. You will have your hands as though you are peering into a bright window at night. Your hands will make a solid structural connection between the body of the binocular, through your hands and thumbs, to your face, and markedly improves how steadily you can hold the instrument. If this out-of-balance position becomes tiring, move one hand out to the objective end of its side of the binocular, so that you are supporting the instrument on opposite sides of its center of gravity. When you get tired, switch hands. 2.17 How can I find birds quickly with my binoculars? Here are some tips from experienced birders: 1. Memorize how you turn the focus wheel to focus closer or farther. 2. Remember at all times how far away you last focused. | 3. After looking at a bird, refocus for where you expect the next bird. | In the woods, this is close. On the beach, this is farther out. 4. Start focusing before the binoculars get to your eyes. | 5. Make a mental note of where the bird is: "third branch to the right | against yellow leaves." Vegetation looks different with and without | binoculars. | 6. Keep looking at the bird while raising the binoculars into your line | of sight. 7. Practice, practice, practice 2.18 What factors affect brightness in optical instruments? Have you noticed that the warbler in the bush at dusk that you can see with binoculars practically disappears without them? The effect is profound and many people believe this is because binoculars and telescopes act as "light buckets" that collect light over a large area, effectively enlarging their eyes. This is true, but the magnification of the lens spreads the light over a larger area and the apparent brightness "per square degree" is no more than with the naked eye. What is really happening is that the lens is enlarging the object without making it fainter. Higher quality optics increase apparent brightness by eliminating reflections. This effect can be substantial, but probably does not cause a dramatic difference in brightness between two pairs of binoculars. The dominant factor is the exit pupil (q.v) which, if smaller than the diameter of your pupil, will decrease brightness. Another factor is contrast, which does not increase brightness but does give the appearance of a brighter view. Lens coatings (q.v.) generally improve contrast. 2.19 What other factors should I consider in buying binoculars? You should consider how you are going to use and treat them. Consider the following questions: o If you have an expensive pair of binoculars, will you be afraid to take them with you? o Do you plan to store the binoculars in your car so they will always be with you? o Can you carry them easily when hiking, biking, or cross-country skiing? Perhaps you want a second pair for this? o Do you plan to use them in very humid/wet environments? o Do the binoculars fit your hands? Binoculars and people come in different shapes and sizes. o Do the lens caps remain attached? Can you remove them easily? 3. Supports =========== Supports for birding with binoculars and scopes come in several forms: tripods, monopods, Finnsticks, shoulder stocks, and window mounts. 3.1 Tripods =========== Owners of most tripod brands report loose parts and some report rust. Tripods are like any other equipment: they require some preventative maintenance. The large majority of US readers use one of two tripods, the Bogen 3021 or the Davis & Sandford RTS. Gitzo also makes fine tripods which are popular among professional photographers. Here's a tip for all you tripod thunkers. To minimize the thunk of the tripod when you open it, hold it horizontally, then pull out and lock the legs. The birds and your fellow birders will appreciate it. If you have problems with vibration, you can always hang a heavy object underneath your tripod to give it more stability and quicker damping time. Astronomy catalogs sell aluminum and rubber gadgets that reduce vibration times by about 3x for about US$40. Bogen (Manfrotto outside the US) Model 3021 (Manfrotto 55) is most popular with birders; lesser models are not sturdy enough; larger models are overkill. With the micro-fluid head, it weighs about 8 pounds (3.5k) without scope, so it requires a strap. However, the weight makes for a steady scope in the wind. The quick release plate for the micro-fluid head is nice, especially for switching between scope and camera. The quick-release leg levers are handy, but take some strength to operate and have a reputation for coming loose. A few birders report tripod collapse as a result. The levers can catch twigs, hair, and binocular straps. Legs can open noisily if not careful. Good height for tall birders. Replacement parts are readily available. With proper maintenance, owners are generally happy with this tripod. Davis & Sanford (Tiffen) Model RTS is no frills, solid, lightweight (4.75 lbs, 2.2k), and fast to open because of its twist-to-unlock legs. Is not as tall as Bogen 3021. [Editor's note: I'm 6'3" (2m) and the Bogen is a better fit.] Owners find this tripod plenty sturdy even with heavy scopes. The pan-head is very simple -- twist the pan-arm to loosen and twist back to tighten in place. The quick change screw for quick release mounting is nice. Owners seem to be universally happy with this tripod. Gitzo While primarily aimed at professional photographers who need stability for monster lenses (400mm+), Gitzo tripods have found some favor among birders. Model 341 (the Inter Pro Studex Rapid) is solid (7 lbs, 3.2k), good for tall birders, and well built. The Bogen fluid head fits this tripod. Drawbacks are that it is expensive (around US$300) and long (29", 75cm) when collapsed. 3.2 Monopods A monopod is not a replacement for a tripod. However, a monopod is an option when weight and bulk are factors. When I travel by air, I pack a monopod, scope, and binocs into my briefcase along with the appropriate field guides, leaving my hands free for luggage and portable computer. Monopods lack stability (especially in the wind) and have only limited height (I perch mine on a rock where possible). 3.3 Finnsticks A finnstick is literally a stick, usually with a fork at one end, which you use to hold your binoculars at eye-level, allowing you to keep your arms down. Consequently, you keep your view steadier for longer periods. Finnsticks are useful in any endurance situation: hawk watching, sea watching, and pelagic trips. These sticks originated in Finland where they are called staijikeppi (pronounced: stah-yeeh kep-peeh). Most finnsticks are homemade (since they apparently have a proclivity for getting lost) from branches 1.5-2 inches (4-6cm) in diameter, 2-3 feet (60-100cm) in length, with a natural fork in one end. This fork, with perhaps a little carving, fits under the center barrel of the binoculars. 3.4 Shoulder Stocks A shoulder stock is device similar to the stock of a gun, on which you mount a scope or camera. Some people prefer a shoulder stock for its mobility and portability. They are excellent for following the path of a moving bird; however, the scope is only as steady as your arm and your arm will get tired quickly. 3.5 Window Mounts Several manufacturers make scope mounts that slide over and fasten to a car window. These are useful for birding impoundments and fields accessible by car. Although very handy, they transfer all vibrations from the car to the scope, so you have to turn off the car and they also can take infuriatingly long to attach to the window. An alternative is a small (usually homemade) bean bag that rests on top of the window (or car roof, boulder, limb). See the Dec 1992 _Birding_ for more details. 4. Ratings 4.1 Better View Desired (Scopes and Binoculars -- November 1993) ============================================================== [This list also contains recommdations from the February 1994 issue.] The following selections come from the November 1993 issue of _Better View Desired_, Stephen Ingraham's newsletter devoted to evaluating birding optics. These selections are in two categories: Reference Standard, products that set the performance standard for their class; and, Best Buy, products with outstanding performance at an affordable price. Reference Standard: the performance standard for its class Compact Binoculars : Bausch & Lomb Custom 7x26 Mid-sized Binoculars : Optolyth Alpin 8X30 Full-sized 7x & 8x Binoculars : Zeiss 7X42 High-power Binoculars : Celestron 9.5X44ED 50-60 mm Spotting Scopes : Nikon Fieldscope ED 70-80 mm Spotting Scopes : Tel Vue Pronto Catadioptric Scopes : Questar Birder Best Buy: outstanding performance at an affordable price Mid-sized Binoculars : Celestron Ultima 8x30 Full-sized 7x & 8x Binoculars : Swift Ultralite 8x42 High-power Binoculars : Swift Ultralite 10x42 50-60 mm Spotting Scopes : none 70-80 mm Spotting Scopes : Celestron S80+ Compact Binoculars : Bausch & Lomb Legacy 8x24 Minolta Compact 8x23 Nikon Travelite 8x23 Pentax UCF 8x24 Swift Micron 8x25 Mid-sized Binoculars : Celestron Ultima 8X30 Full-sized 7x & 8x Binoculars : Swift Ultralite 8X42 High-power Binoculars : Swift Ultralite 10X42 50-60 mm Spotting Scopes : none 70-80 mm Spotting Scopes : Celestron S80+ Catadioptric Scopes : Celestron C90 Products of Special Merit: not quite top products, but certain outstanding characteristcs. Compact Binoculars : Nikon Diplomat 10x25 Full-sized 7x & 8x Binoculars : Swift Audubon 8.5X44 (exceptional resolution and ease of view at a very reasonable price) Zuka Scope (hand holdable Newtonian Telescope) Celestron C5 (perhaps the highest resolution and brightness of any spotting scope currently available in a moderately compact package. The ultimate long distance scope.) 4.2 Living Bird (Binoculars -- Autumn 1992) =========================================== [Thanks to Sid Johnson for this report from "Binocular Quest", _Living Bird_, Autumn '92, T. Culver and H. Gerhart. All prices in US dollars.] Suggested List Prism Model Price $US Type Armor? Warranty Over US$800: * Bausch & Lomb Elite 10x42 $1,956 Roof Yes Limited Lifetime * Bausch & Lomb Elite 8x42 $1,900 Roof Yes Limited Lifetime * Bausch & Lomb Elite 7x36 $1,704 Roof Yes Limited Lifetime * Leica Ultra 10x42 BA $1,590 Roof Yes Lifetime * Leica Ultra 8x42 BA $1,590 Roof Yes Lifetime Nikon Classic Eagle 8x40 DFC $1,232 Roof No 25-year Limited * Zeiss Dialyt 10x40 B/GAT $1,250 Roof Yes Lifetime * Zeiss Dialyt 7x42 B/GAT $1,215 Roof Yes Lifetime US$500-US$800: aus Jena Luxus 10x40 $775 Roof No Limited Lifetime Bausch 7 Lomb Custom 10x40 $528 Porro Yes Limited Lifetime Nikon Execulite 9x30 $567 Roof No 25-year Limited * Nikon E CF HP 8x30 $512 Porro No 25-year Limited * Optolyth Touring 10x40 $608 Roof Yes Limited Lifetime Swift Audubon 7x35 $600 Roof Yes Lifetime US$200-US$500: Celestron Ultima 10x42 $350 Porro No Limited Lifetime Celestron Ultima 8x32 $350 Porro No Limited Lifetime Minolta Weathermatic 7x42 $406 Roof Yes 25-year Limited Optolyth Alpin 10x40 $360 Porro Yes Limited Lifetime Optolyth Alpin 7x42 $360 Porro Yes Limited Lifetime Optolyth Alpin 8x30 $298 Porro No Limited Lifetime Pentax DCF 8x42 $375 Roof No Original Owner Pentax PCF 7x50 $220 Porro No Original Owner Pentax PCF 7x35 $200 Porro No Original Owner Redfield WP 10x50 $407 Roof Yes Limited Lifetime Redfield WP 7x35 $361 Roof Yes Limited Lifetime Swift Audubon 8.5x44 $399 Porro No Lifetime * Swift Ultra Lite 8x42 ZWCF $345 Porro Yes Lifetime Swift Egret 10x42 HCF $288 Roof Yes Lifetime Under US$200: * Bushnell Birder 7x35 $75 Porro No Limited Lifetime Minolta Standard 7x35 $141 Porro Yes 25-year Limited Compacts: * Bausch & Lomb Custom Compact 7x26 $457 Rev. Porro No Limited Lifetime Leica 10x25 BCA $645 Roof Yes Limited Lifetime Leica 8x20 BCA $615 Roof Yes Limited Lifetime Minolta Pocket 7x21 $137 Rev. Porro No 25-year Limited Minolta Compact 8x23 $132 Rev. Porro No 25-year Limited Nikon Travelite III 9x25 $156 Rev. Porro No 25-year Limited Pentax UCF 8x24 $160 Rev. Porro No Limited Lifetime Redfield 8x24 $210 Roof No Limited Lifetime Swift Micron 8x25 CF $120 Rev. Porro No Limited Lifetime Zeiss Design Selection 8x20 BT $530 Roof No 25-year * Top rated Play of Interpupil Good for Weight Focus Model Distance Eyeglasses? (ounces) (degrees) Over US$800: * Bausch & Lomb Elite 10x42 2-3/16" - 2-7/8" 2 28.1 400 * Bausch & Lomb Elite 8x42 2-3/16" - 2-7/8" 1 29.1 400 * Bausch & Lomb Elite 7x36 2-3/16" - 2-7/8" 1 25.4 400 * Leica Ultra 10x42 BA 2-3/16" - 2-7/8" 2 32.0 330 * Leica Ultra 8x42 BA 2-3/16" - 2-7/8" 2 32.0 330 Nikon Classic Eagle 8x40 2-1/8" - 2-13/16" 2 28.2 190 * Zeiss Dialyt 10x40 B/GAT 2-3/16" - 3" 2 26.4 330 * Zeiss Dialyt 7x42 B/GAT 2-1/4" - 2-15/16" 1 28.2 450 US$500-US$800: aus Jena Luxus 10x40 2-3/16" - 2-7/8" 3 24.6 270 Bausch 7 Lomb Custom 10x40 2-1/4" - 2-13/16" 2 30.9 460 Nikon Execulite 9x30 2-3/16" - 2-7/8" 4 16.7 630 * Nikon E CF HP 8x30 1-7/8" - 2-7/8" 2 20.0 330 * Optolyth Touring 10x40 2-1/8" - 3" 2 24.0 410 Swift Audubon 7x35 2-1/4" - 3-1/16" 2 21.0 460 US$200-US$500: Celestron Ultima 10x42 2" - 2-7/8" 2 19.7 360 Celestron Ultima 8x32 2" - 3" 2 17.4 370 Minolta Weathermatic 7x42 2-1/4" - 2-7/8" 1 29.1 270 Optolyth Alpin 10x40 2" - 2-3/4" 4 18.2 690 Optolyth Alpin 7x42 2" - 2-3/4" 2 18.1 690 Optolyth Alpin 8x30 2" - 2-3/4" 4 14.9 690 Pentax DCF 8x42 2-1/4" - 2-7/8" 2 31.0 360 Pentax PCF 7x50 2-3/16" - 2-3/4" 2 31.8 590 Pentax PCF 7x35 2-3/16" - 2-3/4" 3 24.3 560 Redfield WP 10x50 2-3/8" - 3-1/16" 3 28.6 170 Redfield WP 7x35 2-5/16" - 3-1/16" 2 20.5 170 Swift Audubon 8.5x44 2-1/8" - 3-1/4" 2 28.9 460 * Swift Ultra Lite 8x42 ZWCF 2" - 2-15/16" 2 21.0 370 Swift Egret 10x42 HCF 2-1/4" - 2-13/16" 4 18.3 320 Under US$200: * Bushnell Birder 7x35 2-3/16" - 2-7/8" 3 18.8 460 Minolta Standard 7x35 2-3/16" - 2-13/16" 3 26.8 270 Compacts: * B&L Custom Compact 7x26 2-1/4" - 3-1/8" 2 11.5 370 Leica 10x25 BCA 1-1/4" - 3-1/4" 4 8.8 740 Leica 8x20 BCA 1-1/4" - 3-1/4" 4 8.1 740 Minolta Pocket 7x21 1-3/8" - 2-3/4" 4 9.7 350 Minolta Compact 8x23 2-1/4" - 2-7/8" 4 8.8 340 Nikon Travelite III 9x25 2-1/8" - 2-7/8" 4 9.4 350 Pentax UCF 8x24 2-3/16" - 2-15/16" 4 9.9 590 Redfield 8x24 1-3/8" - 3-1/16" 4 9.6 270 Swift Micron 8x25 CF 2-1/4" - 2-13/16" 4 10.1 740 Zeiss Design Selection 8x20 1-1/4" - 2-7/8" 4 6.4 350 * Top rated Numeric Ratings: 1 to 5, 1 is best Optical Min. Field of Focus Bright- Perfor- Focus View at Model Feel ness mance Dist. 230' Fog Over US$800: * Bausch & Lomb Elite 10x42 1 2 1 11' 23.8' N * Bausch & Lomb Elite 8x42 1 1 1 10.5' 27.5' N * Bausch & Lomb Elite 7x36 1 1 1 5' 30' N * Leica Ultra 10x42 BA 1 2 1 14' 20' N * Leica Ultra 8x42 BA 1 1 1 12' 20' N Nikon Classic Eagle 8x40 DFC 1 3 2 14.5' 27.5' N * Zeiss Dialyt 10x40 B/GAT 2 3 1 15' 20' N * Zeiss Dialyt 7x42 B/GAT 1 1 1 9.5' 30' N US$500-US$800: aus Jena Luxus 10x40 1 3 2 18' 20' N Bausch 7 Lomb Custom 10x40 1 3 2 12' 20' Y Nikon Execulite 9x30 1 5 2 11' 22.5' Y * Nikon E CF HP 8x30 1 2 1 11' 32.5' Y * Optolyth Touring 10x40 2 3 1 16' 27.5' Y Swift Audubon 7x35 2 2 2 10' 20' N US$200-US$500: Celestron Ultima 10x42 1 2 2 15' 23.8' Y Celestron Ultima 8x32 2 4 3 12' 30' Y Minolta Weathermatic 7x42 1 3 3 12' 25' N Optolyth Alpin 10x40 1 3 3 14' 25' Y Optolyth Alpin 7x42 1 5 3 27' 25' N Optolyth Alpin 8x30 1 5 3 13' 32.5' Y Pentax DCF 8x42 1 5 3 24' 27.5' N Pentax PCF 7x50 2 1 3 15' 22.5' Y Pentax PCF 7x35 2 3 4 7' 25' Y Redfield WP 10x50 2 4 3 24.5' 22.5' N Redfield WP 7x35 2 4 3 10.5' 25' N Swift Audubon 8.5x44 1 3 2 10.5' 31.25' Y * Swift Ultra Lite 8x42 ZWCF 1 2 2 16' 20' N Swift Egret 10x42 HCF 1 5 3 14' 25' N Under US$200: * Bushnell Birder 7x35 2 2 3 13' 22.5' Y Minolta Standard 7x35 2 3 3 12.5' 32' Y Compacts: * Bausch & Lomb Custom Comp. 7x26 1 1 2 6' 27.5' Y Leica 10x25 BCA 3 4 3 16' 20' N Leica 8x20 BCA 3 4 4 8' 26.3' N Minolta Pocket 7x21 2 4 5 6' 26.3' N Minolta Compact 8x23 2 3 5 21' 25' Y Nikon Travelite III 9x25 2 2 3 12' 20' Y Pentax UCF 8x24 3 2 5 8.5' 25' N Redfield 8x24 2 4 5 14.5' 28.5' N Swift Micron 8x25 CF 2 3 4 6' 20' Y Zeiss Design Selection 8x20 BT 2 3 4 8' 25' Y * Top rated Numeric Ratings: 1 to 5, 1 is best 4.3. British Birds (Owner Survey, Binoculars and Scopes, July 1991) ================================================================== From _British Birds_, 84:7, July '91, pp. 267-282. Thanks Adrian Wander. Most Popular Binoculars ----------------------- 1 Zeiss West Dialyt 10*40 28.4% 2 Zeiss West 7*42 8.8% 3 Leitz Trinovid 10*40 6.0% Other well known makes placed: 4 Swift Audubon 8.5*44 5.5% 5 Optolyth Alpin 10*40 4.9% 11 Bausch and Lomb Elites 10*42 1.7% 6 Optolyth Alpin 10*50 4.2% 12 Bausch and Lomb Elites 8*42 1.4% 7 Zeiss Jena Jenoptem 10*50 3.7% 13 Leica 10*42 1.3% 8 Leitz Trinovid 8*40 2.8% 16 Leitz Trinovid 7*42 1.2% 9 Swarovski/Habicht Diana 10*40 2.4% 17 Zeiss West Dialyt 8*30 1.1% 10 Zeiss Jena Notarem 10*40 1.9% Most Highly Rated Binoculars ---------------------------- (6=excellent 5=very good 4=good 3=satisfactory 2=poor 1=very poor) Make No Owners Average Rating 1 Bausch and Lomb Elite 8*42 12 6.00 2 Leica 10*42 11 6.00 3 Optolyth 9*63 5 6.00 4 Zeiss West 7*42 72 5.94 5 Leitz Trinovid 8*40 23 5.87 6 Bausch and Lomb Elite 10*42 14 5.86 7 Leitz Trinovid 7*42 10 5.80 8 Leitz Trinovid 10*40 50 5.78 9 Zeiss West Dialyt 10*40 241 5.76 10 Leica 8*42 4 5.75 (13 Zeiss West Dialyt 8*30 9 5.56 14 Swarovski/Habicht Diana 10*40 20 5.50 20 Zeiss West 10*50 4 5.25 21 Swift Audubon 8.5*44 46 5.20 23 Optolyth Alpin 8*40 11 5.09) Most Satisfactory Binoculars (number of owners who would buy the same again) ---------------------------------------------------------------------------- 1 Leica 8*42 4/4 100.0% 2 Bausch and Lomb Elite 8*42 11/12 91.7 3 Zeiss West 7*42 61/73 83.6 4 Leica 10*42 9/11 81.8 5 Bausch and Lomb Elite 10*42 11/14 78.6 6 Optolyth Alpin 8*30 2/3 66.7 7 Zeiss West Dialyt 10*40 154/236 65.3 8 Nikon 8*30 4/7 57.1 9= Swarovoski/Habicht Diana 10*40 10/20 50.0 9= Opticron Classic 10*42 3/6 50.0 (14 Swift Audubon 8.5*44 15/46 32.6 15 Optolyth Alpin 10*40 13/41 31.7 16 Leitz Trinovid 7*42 3/10 30.0 20 Optolyth Alpin 10*50 9/35 25.7 21 Leitz Trinovid 10*40 12/50 24.0 22 Leitz Trinovid 8*40 5/23 21.7 24 Optolyth Alpin 8*40 2/11 18.2 26 Zeiss West Dialyt 8*30 1/9 11.1) Top Binoculars for the Future (intended future purchases) --------------------------------------------------------- 1 Zeiss West Dialyt 10*40 28.5% 2 Zeiss West 7*42 13.8% 3 Leica 10*42 8.8% Other well known makes placed: 4 Leica 8*42 4.2% 5= Leitz Trinovid 10*40 2.8% 11 Optolyth Alpin 10*50 1.8% 5= Swift Audubon 8.5*44 2.8% 14 Leitz Trinovid 8*40 0.8% 7= Bausch and Lomb Elites 10*42 2.6% 16 Swift Audubon 7*35 0.7% 7= Bausch and Lomb Elites 8*42 2.6% 18 Zeiss West Dialyt 8*30 0.5% 9 Optolyth Alpin 10*40 2.3% 10 Swarovski/Habicht Diana 10*40 1.9% Most Popular Scopes ------------------- 1 Kowa TSN1/2 *77 16.2% 2 Bushnell Spacemaster *60 12.2% 3 Kowa TSN3/4 *77 7.7% 4 Optolyth TBS/G80 7.5% 5 Optolyth 30*75 6.9% 6 Nikon Fieldscope EDII *60 5.8% 7 Kowa TS1/2 *60 4.7% 8 Nikon Fieldscope ED *60 4.5% 9 Opticron High Resolution *60 3.6% 10 Bushnell/Bausch and Lomb Discoverer 15-60*60 3.2% (11 Optolyth 30*80 2.1% 12= Questar Mirrorlens 1.9%) Most Highly Rated Scopes ------------------------ (6=excellent 5=very good 4=good 3=satisfactory 2=poor 1=very poor) Make No Owners Average Rating 1 Questar Mirrorlens 15 6.00 2 Kowa TSN3/4 *77 59 5.93 3 Nikon Fieldscope EDII 40 5.90 4 Nikon Fieldscope EDI 36 5.89 5 Nikon Fieldscope I and II 7 5.71 6 Optolyth TBS/G80 62 5.56 7 Kowa TSN1/2 *77 125 5.46 8 Optolyth 30*80 16 5.38 9 Adlerscope 25*80 3 5.33 9= Swarovski/Habicht 30*75 3 5.33 (11 Optolyth 30*75 52 5.17 13=Kowa TSN1/2 36 5.00 15 Bushnell Spacemaster *60 94 4.86 18 Bushnell/Bausch and Lomb Discoverer 15-60*60 25 4.52) Most Satisfactory Scopes (number of owners who would buy the same again) ------------------------------------------------------------------------ 1 Kowa TSN3/4 *77 47/59 79.7% 2 Nikon Fieldscope EDI and II 58/76 76.3% 3 Questar Mirrorlens 11/15 73.3% 4 Optolyth TBS/G80 31/62 50.0% 5 Nikon Fieldscope I and II *60 3/7 42.9% 6 Optolyth 30*80 6/16 37.5% 7 Adlerscope 25*80 1/3 33.3% 8 Kowa TSN1/2 *77 37/125 29.6% 9 Optolyth 30*75 13/53 24.5% 10 Bushnell Spacemaster *60 19/94 20.2% (14 Kowa TSN1/2 *60 4/36 11.1% 16 Bushnell/B&L Discov. 15-60*60 1/25 4.0%) Top Telescopes for the Future (intended future purchases) --------------------------------------------------------- 1 Kowa TSN3/4 *77 20.5% 2 Nikon Fieldscope EDI and II 19.3% 3 Optolyth TBS/G80 9.2% 4 Kowa TSN1/2 *77 8.8% 5 Questar Mirrorlens 3.5% 6 Bushnell Spacemaster *60 3.2% 7 Kowa TS601/602 *60 2.7% 8 Optolyth 30*75 2.3% 9 Optolyth 30*80 1.6% 10 Nikon Fieldscope I and II 0.9% 4.4 Living Bird Quarterly (Scopes -- Autumn 1990) ================================================= This summarizes "Scanning for Optics II" from _The Living Bird Quarterly_, Autumn '90, pp 12-15, Bonney and Forbes-Robertson. Highest rating is 1, lowest is 5. 1. Kowa TSN-4 and TSN-2: winners; zoom clear; if you have the money, buy the 4. 1. Nikon ED II Fieldscope: excellent; smaller, lighter than Kowas; zoom clear; focus ring awkward; depth of field shallow. 2. Optolyth TBG80: very good; image not sharp at high power; smaller field- of-view than Kowa; shallower depth of field. 2. Mirador SSD: can't match TSN-2; good clarity, but dark. 2. Bausch & Lomb Elite 22x: not as clear as some; outstanding for eyeglasses. 3. Questar Field Model: phenomenal image; 6x, 50x, and 80x impractical for most birding; heavy. 3. Celestron C-90: heavy; bright, clear image; small field-of-view; 33x only; focus awkward. [additional owner comments: also available is a 25mm orthoscopic eyepiece that yields closer to 40x; slow motion head available; Barlow lens accessory doubles power while retaining eye relief for glasses wearers; comes in stout camera case.] 3. Zeiss 30x60 B/GA: image bright, but mediocre; not up to Zeiss reputation. 3. Bausch & Lomb Elite 15-45x: only good, unlike 22x; image worse as zoom increases. 3. Bushnell Spacemaster: best inexpensive scope; use 22x, zoom not good. 4. Optolyth 22-60x 70mm: image excellent; field-of-view tiny; shakes in wind. 4. Swarovski 25-40x 75 NZ and 30-75x 75 NZ: didn't care for either. 4. Celestron C-60: disappointment; dark and moderately clear. 5. Meade Pathfinder II and Swift Searcher: bad image. 5. Sources for Optical Equipment ================================ If you belong to a buying service, try that first. One example: B & L Elite 22 x 60 scope, list: US$750, best mailorder: US$400, buying service: US$200. Several credit cards offer buying services. Another buying service that is somewhat widespread throughout the US is United Consumers Club. Also, check the New York City mail order sources that advertise in the back of Popular/Modern Photography. Be aware, however, that these places often carry what are known as foreign market or grey market goods. These are products produced for sale in countries other than the US. Sometimes these products are manufactured to different specifications; sometimes they are identical. In any case, you will not have any US warranty on the goods and may not get any frills either (carrying case, strap, etc.). The prices are appealing, but caveat emptor. Mail order purchases from New York discounters can be practical from outside the US. Many Australasian netters have successfully ordered from B & H. You typically pay about US$50 extra for insurance and express mail. Even with the extra costs, your price may be considerably less than the best locally available discount price. In Australasia, this is typically about 2/3 of the best local price, assuming you pay import duty (in Australia) or GST (in New Zealand). These taxes appear to be random; you may not be charged. If you travel overseas and can purchase duty-free, then the price difference is much smaller, and you may want to deal locally for the convenience of service and repair. With your order comes an international guarantee, but you must ship your purchase to your local distributor in the event that you need to use it. Before buying any mail order optics, you should read the Mail Order Survey that Douglas Blondin (blondin@blanca.att.com) maintains. He posts this survey, listing experience with most of national photographic and optics stores, about once a month on rec.photo and rec.video. The sci.astro newsgroup is a good place to ask about optics suppliers. On this group, you will also find the Purchasing Amateur Telescopes FAQ that Ronnie B. Kon (ronnie@cisco.com) maintains. Birders often sell optical equipment as they upgrade to newer models. Generally every issue of _Winging It_, the newsletter of the American Birding Association, has offers of used equipment. Suppliers ========= ABA Sales (Colorado Springs, CO) 800-634-7736, 719-578-0607 -- This is the sales organization of the American Birding Association. They do a great job of stocking items for birders. Their optics selection is good and their prices are becoming more competitive. You cannot ask for better service. ABA members get discounts. The catalog has a lot of useful comparisons of optical equipment. Birding (Amsterdam, NY) 518-842-0863 -- APPARENTLY OUT OF BUSINESS B & H (New York, NY) 800-221-5662, 212-807-7474 -- "I have bought tons from B&H...highly approved of by the pros who haunt rec.photo.... They're honest, don't bait and switch, add garbage pieces, tell you how much everything including shipping will cost, when you'll get it, etc.... Their prices run slightly higher than some other NY mail-order houses but honesty and fairness make it worthwhile." Christopher's Ltd (Norman OK) 800-356-6603 -- "primarily an astronomy-oriented optical dealer, but good selection, decent prices, and top-notch advice on many spotting scope options." Their prices are a bit higher than some, but they offer a 30 day return policy (subject to a 15% restocking fee). They have a catalog with much useful information about birding optics, including recommendations about which spotting scopes work best as telephoto lenses. City Camera (Dearborn, MI) 800-359-5085, 313-846-3922 -- They have a birder on staff, and have a helpful flyer and specification. Eagle 608-271-4751 -- "really helpful" Executive Photo, (New York, NY) 800-223-7323, 212-947-5290 -- avoid, based on many negative comments | National Camera (MN) 800-624-8107, 612-546-6831 -- "helpful and | straightforward; prices midway between Eagle or Christopher's and the NY | camera stores; 30-day satisfaction guarantee; Kevin, the optics | manager, was well-informed." Orion (Santa Cruz, CA) 800-447-1001 -- large selection of interest to birders. Prices are fairly high, and service varies depending on who you talk to. Yoder 216-893-2464 6. Useful Reference Material ============================ _Better View Desired_, Whole Life Systems, P.O. Box 162, Rehoboth, NM 87322. Subscriptions are $15 per year (4 issues). A free sample issue will be sent upon request. All back issues are available for $4 per issue: August 1992, Mid-sized Binoculars; November 1992, High-powered Binoculars; February 1993, Refractor Spotting Scopes; April 1993, Budget Binoculars; August 1993, Full-Sized 7 and 8x Birding Binoculars; November 1993, Catadioptric Scopes; February 1994: Compact Binoculars. Culver and Gerhart, "Binocular Quest", _Living Bird_, Autumn 1992. "Binocular and Scope User Survey", _British Birds_, 84:7, July 1991, pp. 267-282. Bonney and Forbes-Robertson, "Scanning for Optics II", _The Living Bird Quarterly_, Autumn 1990, pp 12-15. _Birding_ (photo issue), February, 1989. See also the "Tools of the Trade" column in most issues. 7. Contributors =============== Thanks to the following individuals who have helped with this FAQ: Bob Atkins, Don Baccus, David Braddon-Mitchell, Mike Burger, Byron Butler, Dalcio Dacol, Richard Ditch, Derk Drukker, Mark Eckenwiler, Al Eisner, Dave Eshbaugh, Annika Forsten, Jay Freeman, L. Gorbet, David Graham, Burton Guttman, Sid Johnson, Frank Kolwicz, Tony Lang, Laurie Larson, Tom Lathrop, Harry Lehto, Kevin McGowan, Peter Nurkse, David Rintoul, Rocky Rothrock, Daan Sandee, Sandy Santra, Frank Suits, Brian Townes, Tim Walker, Adrian Wander, Steve Willner, David Wright [I apologize to anyone I have inadvertently left out -- let me know.] -- Ed Matthews Internet: edm@aib.com AIB Software Voice: (703) 430-9247 46030 Manekin Plaza Fax: (703) 450-4560 Dulles, Virginia 20166-6518 USA -- Ed Matthews Internet: edm@aib.com AIB Software Voice: (703) 430-9247 46030 Manekin Plaza Fax: (703) 450-4560 Dulles, Virginia 20166-6518 USA