You've probably seen a very thin sliver of our moon after sunset or before sunrise. Imagine it thinner. And even thinner. Eventually all that's left is sunlight shining off the mountain peaks while leaving the valleys in darkness. This arched 'string-of-pearls' is known as Saber's beads after a comment I made about the visual similarity to what is seen during a solar eclipse.
Just before (and after) the moon passes in front of the sun, light shines at us through the valleys but is blocked by the mountains- the mirrored effect of Saber's beads. After reporting this resemblence, my esteemed stargazing colleagues honored me with its namesake.
While promoted as an outreach term, further scientific study may also provide new insights regarding local albedo values within the lunar libration zones.
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EXTREME CRESCENT SPOTTING TIPS
Set up at a site with as much altitude as possible overlooking an unobstructed horizon.
Optimal sky transparency allows the crescent to be detected and tracked down to, or up from, the horizon.
Using a telescope or binoculars (mounted binos are recommended), fine tune the focus on Venus, Jupiter, or one of the brighter stars beforehand.
For dusk attempts, have Sol's setting azimuth on hand- making note after sunset of a random landmark at that position for reference- as well as Luna's altaz position at sunset thru moonset. Accordingly, for dawn attempts, have Luna's altaz info for moonrise thru sunrise.
As dawn slivers have the advantage of possible detection with dark-adapted eyes, wearing sunglasses during the day prior to sunset attempts is recommended for maximum 'dusk' adaptation.
Once the crescent is acquired in binoculars, walk the bino down to the horizon/random landmark in consecutive FOVs for the approximate naked-eye altaz.
A favorable elongation is important. In the 24 hours before or after New Moon, Luna's angular separation from Sol can vary by several degrees. With a favorable ecliptic, net elongations (as altitude) of 6° or more at sunset or moonrise offer the best window for detection. 8-10° is necessary to catch Saber's beads in optimal/deep twilight.
Illuminated fractions of same-age crescents within 24 hours of New Moon can vary by 200% and a full magnitude of brightness. Slivers near perigee help present a thicker and brighter lunar profile for personal record crescent spotting.
Last but not least, don't always count-out a shallow ecliptic. Occasionally our moon's extreme northern or southern declination will compensate for a less than favorable ecliptic angle.
BRACKETING THE SLIVERS
Another rare and challenging notch for ones lunar bedpost is to catch the consecutive waning and waxing crescents within 24 hours on each side of New Moon.
For instance, July 2008's Buck Moon offered such an opportunity as I was able to spot both the -16.5 hour illumination before sunrise on the 2nd and the +23.5 hour sliver just after sunset on the 3rd.
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EXTREME CRESCENTS AND COLONGITUDE
A big piece of the puzzle concerning the appearance of a thin crescent's degree of segmentation may be predicted by its colongitude at New Moon which, not suprisingly, can vary by more than 10°, trumping the effects and cycling independently of the apogee-perigee lunar profiles. VMA simulations show New Moon colongs less than 270° to favor segmented waxing crescents while those over 270° favor segmented waning crescents. (Those over 270° would be considered 'early' colongitudinal moons).
Equally important to those hunting Saber's beads, colongitude may also be used inversely to determine the best profiles and visibilities for personal record crescent spotting.
The table below shows the lunation, colongitude at New Moon, duration in hours of the most segmented waxing limb (-280° colongitude), and the duration in hours of the most segmented waning/preceding limb (+260° colongitude). Data derived from thin crescent images and my own experiences with extreme crescents also concur with a 260-280° colong window. Of note; the youngest naked-eye crescent sighting to date (May 1990/aged 15.5 hrs), my May '06 sighting (20.5 hrs), and the Lodriguss example above (27.5 hrs) all have a colongitude of 276-278°.
Exact formations involved may vary at each lunation due to libration and other factors. The illuminations caused by sunlit mountainous regions and/or albedo effects also bear further study.
lun/colong/h-280/h+260
1068 274.7 10 28
1069 273.0 13 25
1070 271.1 17 21
1071 269.3 20 18
1072 267.6 24 14
1073 266.0 27 11
1074 264.9 29 09
1075 264.7 29 09
1076 266.0 27 11
1077 268.5 22 16
1078 271.3 16 22
1079 273.5 12 26
1080 274.7 10 28
1081 274.9 09 29
1082 274.4 10 28
1083 273.3 12 26
1084 271.5 16 22
1085 269.3 21 17
1086 267.0 25 13
1087 265.3 28 10
1088 264.7 29 09
1089 265.3 28 09
1090 266.9 25 13
1091 268.9 21 17
1092 271.1 17 21
1093 273.1 13 25
1094 274.7 10 28
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For the record, here's the ELCD from my first observation
of Saber's beads:
New Moon 27 May 2006 0526ut
(@+24hours)
Angular Size/Distance 31.2'/383356km
Colongitude 277.6°
Declination +27°04'
Solar Elongation 13.5°
Mag/% Illumination -1.02/.012
41.5n 90.5w
-24h waxing
moonset window: 01h10m
sunset/azimuth: 0126ut/300*
altaz at sunset: 9.3*/298*
moonset/azimuth: 0236ut/308*
age at sunset: 20h00m
First detected at +20.2 hours, this instance of Saber's beads peaked in deep twilight with the infant crescent hanging 2.0° above the horizon at a solar elongation of 12.2°.
By this time I was fully immersed in the imagery of a total solar eclipse- as if in the next few moments I would either be basking in our sun's corona or forced to turn away from its glare.
This experience left me with the mystery of why the phenomenon had escaped my attention in then over 10 years of diligent young/old crescent spotting, and more so, gone unreported after four centuries of magnified scrutiny.
As a drummer and not a scientist, I've done my best to make some headway into the window parameters for viewing this rare and beautiful lunar aspect.
Note the extreme northern declination and sunset altitude combined with a favorable colongitude and ecliptic which allowed one of the longest moonset windows and highest altitudes at sunset possible for a crescent that age. It is this rarity of catching the fully/near-fully segmented limb in a dark sky that defines the complete phenomenon.
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| Lunar |
Stargazing can be enjoyed using any binocular.
It can be enjoyed even more with binoculars when fully dark-adapted and viewing from a moonless site far from any city lights.
The following is a collection of my thoughts on choosing and using binoculars for stargazing, some reviews, and 150 doublestars to enjoy. A wealth of deepsky targets suitable for binos can be found in the Astronomical League Observe Program lists linked at right.
First, an important warning:
DO NOT EVER LOOK DIRECTLY AT THE SUN, EITHER WITH YOUR UNAIDED EYE OR THROUGH A TELESCOPE OR BINOCULARS, UNTIL YOU ARE THOROUGHLY FAMILIAR WITH THE SAFE METHODS OF OBSERVING THE SUN. DO NOT EVER LEAVE A TELESCOPE OR BINOCULAR UNATTENDED SO THAT A CHILD COULD POINT IT AT THE SUN. PERMANENT EYE DAMAGE OR BLINDNESS COULD RESULT.
*****
Among other factors, choosing binoculars is about trade offs between magnification, aperture, weight, field of view, eye relief, coatings, and price.
Personal preferences are as individual as our eyesight. Go with the binos that satisfy the most important of your own preferences in these areas.
Choosing a size is literally a matter of desired perspective. Various powers and fields shed new light and aesthetics to our celestial treasures. Different instruments for different moods.
Several years ago I had the opportunity to view the night sky thru 2.5x opera glasses. IIRC, the FOV was 20-25°. Felt more like bionic-vision than bino-vision. Quite an interesting experience. Saturn and the lunar detail seen at 30x is always equally as compelling.
10x50s are a recommended first binocular for stargazing. It is the highest magnification that most can hold relatively steady without a tripod while still providing a comfortably large field of view and exit pupil. If buying for a child I would suggest a smaller, lighter 7x35 or 8x40.
I've had a good track record and would recommend ordering from major online dealers such as Orion, Garrett, and Oberwerks, but buying locally or driving to avoid shipping mishaps is always preferable. Good communication and a solid return policy are marks of a reputable online dealer.
Outdoors and hunting supply stores have been known to carry a decent variety of quality instruments. As with scopes, starparties are also a great place to try out and ask about a variety of binoculars. The local astroclub may even have some renters to audition.
SPEAKING OF AUDITIONING BINOCULARS:
SHAKE IT
Make sure nothing is loose or bouncing around inside.
LOOK AT IT
Make sure there are no scratches or cracks on the glass or body.
At arm's length, look for round, unobstructed circles of light thru the barrels and eyepieces.
Quality BAK4 glass is recommended.
Is there a center-focus adjustment?
Are they tripod-adaptable if needed?
MESS WITH IT
Make sure the caps are tight. Make sure the main hinge, focuser, and other adjustments all move smoothly, securely, and with no play.
NOW, LOOK THRU IT
If there's a right diopter dial, close your right eye. Use the center-focus dial for your left eye. Now close your left eye. Use the diopter to focus the right eye.
Can you move the hinge to create a nice, circular image?
Can you see in the entire field comfortably?
Does the image bulge-out or bend-in excessively at the edges? A flat, focused image across most of the field is best.
Is there excessive false color in the field of view.
For handheld use, will you be able to hold the image fairly steady for minutes at a time?
Are the barrels properly aligned? Slowly alternate closing and opening each eye. The image should merge smoothly.
ASK ABOUT IT
Make sure there is a satisfactory guarantee and return policy.
Any binocular that passes these tests to your approval should provide an enjoyable ride under the stars.
*****
CONGRATS ON THE NEW GLASS
Okay, Saber. I'm dark-adapted in the middle of a moonless cornfield away from city lights with my new 10x50. Now what?
Fortunately you read this ahead of time and brought a red flashlight, S&T's Pocket Sky Atlas or a planisphere, Harrington's Touring the Universe through Binoculars or printouts from the AL bino target lists linked above, a blanket or recliner, bug spray or extra clothes, and maybe a notepad and pen.
Or forget all that and just randomly cruise the night sky at your leisure.
There is no wrong way to enjoy the stars.
Note: It's always a good idea to bring something else along that's unique to stargazing.
I once had a lengthy encounter (more lengthy than usual anyway) with the Illinois State Police while getting 'back to basics' in the boonies armed with only an 8x40. On this occasion, without even a star atlas or red flashlight to lend credibility, they had a very hard time believing I was simply stargazing. That I look more like a convict than a cosmologist didn't help matters.
But they eventually decided there were no houses close enough for me to be planning any pillaging or plundering, and left me to my claimed business with the stars.
*****
BEFORE WE GO ON
Receiving any collimated, mechanically-sound binocular with sufficient eye relief/ipd/diopter adjustment while showing minimal false color and pinpoint stars across 75% of the field rates as a very good purchase.
There's no shame in returning an instrument that doesn't meet these basic requirements.
Even though some companies inspect and pack their products better than others, we always roll the dice when mail ordering precision optics. Fortunately the odds are on our side. Of my 25+ online bino purchases only 2 have been untweakable returns.
I should also mention that the world of binoculars, in actual use, is far from an exact science. Specification and mechanical variances are common, even among the same models. Bino experiences and assessments also vary with the individual and visual acuity. In short, try not to let the quest for a perfect binocular take precedence over your enjoyment of the night sky.
Keep this in mind as we dig a little deeper.
*****
MAGNIFICATION/SIZE/FIELD
With binoculars, magnification has a much higher performance emphasis than aperture. The preferred AVI (Adler Visibility Index: Mag X Sq. Root of Aperture) yields the following values:
7x35 40
8x40 50
7x50 50
10x50 70
10x70 85
12x50 85
15x70 125
15x80 135
20x70 165
20x80 180
25x80 225
25x100 250
30x80 270
30x100 300
From this basic list of sizes we see that while a darker sky can easily compensate for 10-20mm of aperture, it barely competes with an instrument offering a 5x larger image scale.
More magnification = More stars, less field, less steady for handheld use.
Less magnification = Fewer stars, more field, more steady for handheld use.
Darker sky = Many more stars. This is also important to remember as we cannot take advantage of any binocular's full aperture until our pupils dark adapt and open to at least match the bino's exit pupil.
*****
BANGIN OFF A THE BRICKS
A brick wall can tell us alot about our binoculars.
Preferably mounted and from at least the minimum focus distance, a bino's magnification and degree of major aberrations can all be quickly field tested against this common building pattern.
Magnification
To determine an instrument's actual magnification, look through the left ocular with your right eye (or vice versa) while keeping both eyes open. The magnified view will be superimposed with the unaided view. Count the number of 1x bricks that traverse a single magnified brick. +/-0.5- 1.0x variances are not uncommon.
Aberrations
Spherical: Softness over entire field. None of the image will not come to a crisp focus.
Astigmatism: Horizontal lines will appear in focus and vertical lines out of focus, or vice versa.
Curvature: Periphery of field will appear in focus and center of field out of focus, or vice versa.
Coma: More noticable under the stars, the images show comet-like extensions increasing toward the periphery.
Distortion: Straight lines bend in toward the center of the image (positive/pincushion) or away from the center of the image (negative/barrel).
Note: Minimal positive distortion at the edges is a good thing, and usually intentionally introduced. It helps sharpen up the inner field.
Chromatic: Images are blurred with false color at the fringes. In general, the higher the magnification, the more noticable the chromatic aberration.
Any excessive daytime aberration will also take its toll on the even more stringent proving grounds of the night sky.
*****
Eye relief and comfort at the eyepieces have always been the first dealmaker/breaker considerations with all of my bino purchases.
I've auditioned several binos that, while wonderful in all other aspects, only offer an inaccessible 6-9mms of ER.
Extraneous eye relief, OTOH, is a comparatively much easier issue to deal with. While eye placement can be more critical, extending the eyeguards or cups is usually all that is required.
Most would agree that extra ER is preferable to not having enough.
Without eyeglasses a minimum useable eye relief (ER minus lens recess) of 10mm is recommended. Those who wear glasses often require at least 16mm to take in the entire field. There are a few more caring dealers that go so far as to relate the actual useable eye relief.
Otherwise, the following rules of thumb tend to apply;
No ER spec mentioned: Embarrassingly and/or painfully short.
ER mentioned: Subtract 2-6mm for recess.
'Long eye relief' mentioned but not qualified: Roll the dice.
*****
Few binoculars are completely unaffected by false color on Luna and the brighter celestial targets. Outside of using expensive apo glass, chromatic aberration in binoculars tends to come with the fast F/R territory. Increased magnification generally amplifies any apparent CA.
Full multi-coatings (FMC) decrease internal reflections and increase night sky contrast. IME, this contrast also increases CA on the bright stuff.
Standard fully-coated (FC) binos often show less false color at the expense of increased internal reflections.
As there are maybe a handful of celestial sources out of billions that might create offensive CA, most will opt for the reduced reflections and better contrast provided with FMC or MC (multi-coated) models.
*****
While a binocular's exit pupil is not unimportant, it is often overrated. Darker skies, higher magnification, and superior AR coatings can all more than compensate for any loss of image brightness due to a smaller exit pupil.
Larger exit pupils often have the advantage of more forgiving eye placement, but sufficient eye relief again plays an important role in the amount of vignette and attaining optimal eye position.
Smaller ExPs also stop down eye pupil aberrations which commonly increase toward the periphery.
City vs Rural
Binos gulp in lots of skyglow along with the stars from the city which wreaks havoc on our pupils' dilation and dark adaptation. Smaller exit pupils will stop down the magnified peripheral skyglow which at least gives our cones a better signal to noise ratio for detecting detail, but any build up of rhodopsin is still largely prohibited. After scanning the bright city skies most have lowered their binocular to find a naked eye circular field of bleached rhodopsin waiting for them (or in one eye after viewing at the scope). Closing our eyes to get a semblance of decent DA back is futile as any rhodopsin build up will scatter soon after we raise the bino to start another round. That we're not also fighting our own physiology is why dark skies provide us with a dramatic increase in detection above what might be academically expected.
3-5mm exit pupils are fine from any LVM. Try 5mms and up from very dark sites for better performance. Even if the nok's ExP exceeds our own under rural skies, the unused incoming 'good' light is at least not detrimental- and even allows more room to maneuver behind the eyepieces.
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One should expect a mechanically sound and collimated mail order binocular whether they've paid 500 dollars or 50 dollars.
Unless you're an accomplished tinkerer, attempting a DIY prism alignment via the tiny adjustment screws also runs the risk of voiding any warranty by accidentally scratching or otherwise damaging the instrument. There's also the possibility that the prisms are fine, but the barrels are poorly aligned.
Mail order and precision optics will never mix, but my advice is to return the binocular when possible and ask for overnight shipping on a properly inspected model.
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I'm not a big tripod fan, but it is a necessary evil for getting the steadiest views and detail from any binocular. Mounted binos also allow increased resolution and detection of targets as much as 2 magnitudes fainter than those seen in freehand views.
For handheld use one can create a human tripod by resting both elbows on a support (car, railing, etc.). Some find more braced stability when using heavier instruments. Observing prone or in a recliner is often recommended. Holding big binos closer to the objectives can also provide more comfortable ergonomics.
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why binoculars...
It's the grab n' go freedom and wide fields.
It's the increase in depth perception and signal strength (on-axis and peripheral).
It's the effortless navigation, straight thru viewing, and more natural extension of our own eyes.
My first serious glass was a giant binocular.
One would still be hard pressed to find me basking under the stars without 80mm guns at my side.
what am I getting into with larger/hi-mag binoculars?
You're getting into more weight/tripod use, less steady freehand views, less field, and possibly more obvious CA (amplified by magnification).
Fortunately this all takes a back seat to the increase
in resolution, detail, and exponential bombardment of stars.
10x vs 15x...
For stargazing purposes I'd go so far as to say 15x70s are becoming the new 10x50s- especially in light polluted skies. Certainly a popular next step up. 15x can be a shaky ride, but not beyond some measure of adaptation.
The case could be made that 15s show so much more that we want/need to see it even steadier. Apparent shake at higher mags is also amplified by the smaller fov.
With practice freehanded stability with 15x70s is not beyond a good deal of improvement, but tripod-mounted (or image stabilized) noks will always offer the best views at any power.
dealing with dew...
Storing binoculars in a secure garage or vehicle has been my best dew prevention. The less change in temperature they have to endure, the better.
Or simply buy more binos.
Maybe tool around with a different power/fov while the other bino defrosts.
saturn thru binos...
I've seen the ring gaps thru 10s and 15s at favorable inclinations. Not what I'd call a crisp image, though. At 25x I start looking (in vain) for Cassini's. Oohs and ahhs from the public thru 30s, plus Saturn's four brightest moons on a good night.
'ruby' coatings...
Not recommended under the stars and not to be confused with anti-reflective (AR) coatings. This gimmick reduces daytime glare by filtering the red spectrum- which only provides darker, dull images at night.
nokking venus...
Magnifications necessary to show the phases of Venus can change rapidly. While 30x will reveal the phase at most any aspect, the thin but large crescent's orientation near inferior conjunction can be detected naked eye. Glare and bad seeing are minimized by catching our sister planet at its highest elevation in the daytime sky.
why dangle...
WA (wide angle) models are always desirable, provided the extra field is free from excessive aberration.
galaxies thru binoculars...
Hunting most galaxies with binos is limited to being an exercise in detection and judge of sky conditions. Yet I still find the repeated mere validation of their continued presence through modest glass to be an amazing aphrodisiac.
At the other size extreme, dark site excursions through the thick arms of our Milky Way and across the Big and Little Magellanics are binocular nirvana.
on zoom binos...
Not recommended for those primarily interested viewing the night sky.
Fixed-power binoculars (up to ~20x) offer up to a 50% wider view than zoom binoculars set to the same magnification.
Decreased optical precision due to the difficulty of keeping the zoom elements of each eyepiece in perfect syncronization, and difficulty to handhold at higher magnification are other disadvantages.
jove thru binos...
I've detected the two main bands at 15x.
Much more obvious at 20x.
At 25x, color and band asymmetries are often detected.
At 30x I have detected the SEB break occupied by the GRS (no detail).
if vs cf...
Individual focus designs do not use a focuser bridge and are ideally less prone to defocus when we press against them. IFs also provide better waterproofing. A personal preference to stargazers aimed at infinity, but not a popular choice for various and repetitive distance refocusing during daytime use. A majority find center focus/diopter focusing to be adequate and most convenient.
getting into the (handheld) zone...
The best way to steadily hold your binocular is another subjective preference, and may vary by size, weight, and ergonomics of the instrument. But more important is the time and experimentation one puts into reaching their own acceptable stability. Striving for handheld stability is also excellent precision exercise for the eyes.
Getting in the 'heartbeat-limited' zone takes patience and practice, but many can eventually become capable of useable, detailed stability almost out of the gate.
Darker skies (more stars) are again recommended here for the increased reference points to accelerate coordination.
hi-mags for steadier views...
Freehanding the stars with 20x (or higher) binoculars takes practice and patience to keep the views even marginally worthwhile. In the end, alot depends on how much stability we're willing to sacrifice.
The point is that we can and do get better at it as the thousands of coordinating neurons and fast twitch muscles involved adapt.
In addition, the more intense eye/brain/reflex 'training' at higher magnifications can also pay off when gearing down to freehand views at lower power (IS binos excluded).
One of many reinforcing experiences with this happened just a few nights ago. After about an hour of casually picking off Messiers with a 20x80 I went back to my vehicle to warm up and wait for the sky to turn. A Marathon-virgin 11x56 was in arm's reach and I decided to revisit my accumulated treasures with the more modest but eager glass.
Excellent wider field views aside, the relative image steadiness now rated just this side of mounted (caffeine and below zero wind chill notwithstanding). The increased handheld stability was notably more than just that which might be expected. Whether this effect is initially only perceived or enhanced by experience and adapted skill, it seems IME an exercise worthy of merit for increasing stability with more commonly handheld magnifications. (Even 15x views become easier to steady after roadtripping with 25-30x noks for awhile.)
A loose analogy to this hi-mag training might be taking practice swings on deck with a ring-weighted baseball bat.
Spend 20 minutes or so with a hi-mag nok in a/your favored braced position on a big, busy target (Luna and Pleiades work well) before dropping down in power. The actual physical/coordinative gains are cumulative, but even the expected stability difference can be enhanced out of the gate.
Another good reason to buy that first hi-mag binocular as well.
*as always ymmv*
for those unaware...
There's more to binocular alignment than prism
screws. The machining and matching grooves of the barrels must also be precise (and the objective itself for that matter). The angle tolerance of the barrels can be even more strict than those of the prisms.
I cite a recent example of a friend, fed up from tinkering with his bino's prism screws, who gave me his non-refundable 20x80 stating, ''If you can fix em, you can have em".
The dizzying view was indeed so far out of alignment that it soon proved to be beyond the screws' adjustment capabilities.
I had another of my 80mm noks nearby and swapped barrels with the troublemaker. The image merged perfectly. Only one of the barrels was bad. The donor 80mm, however, was throwing a fit over its painful, unexpected handicap.
My solution?
Spinning both 70mm barrels from one of my more expendable 15x instruments onto the former 20x troublemaker. Again, the image merged perfectly, and I have a light-weight hybrid 20x70 for my efforts.
Of note, the three binos mentioned are all different brands yet compatible at the hip. Also, there are limits to barrel-swapping on a number of fronts
(which I plan on exploring) that in this case were not exceeded.
The moral of the story is simply that binocular misalignment is not always in the prisms. Another good justification for keeping a well-stocked arsenal of binoculars, too.
the c word revisited...
If cranking the prism screws more than half a rotation either way doesn't solve an alignment problem, I'd start looking somewhere else.
Recently I found another related potential culprit in the crossbracing assembly of applicable models (ironically the feature intended to reinforce proper collimation).
A simple thing really. It's the brace's bolt connecting the objectives. If it's loose or not tightened at the barrels' optimal distance the binocular loses collimation.
In my case it was a fairly easy fix. When the bolt is loose/loosened it allows some play between the fat ends. Gently pushing them in or out while viewing will show whether the objectives (hopefully only laterally) need to be locked closer or farther apart. Note: check that the connector at
the bar's other end is also secure.
FWIW, this 80mm nok, purchased from one of the big 3 for $189, attained conditional alignment with the barrels locked 30mm apart. It's a good bet that the bargain priced counterparts are at least as susceptible.
I'm not especially advocating this repair approach.
In fact, I recommend sending such an instrument back and asking for a properly inspected model to be mailed asap with free overnight shipping.
But in this case it was a quick fix, the bino remains aligned, the song remains the same, and we have another fun insight into the wonderful world of miscollimation.
one person's miscollimation is another's elation...
I remember one starparty visitor who brought his own 7x50 binocular which he insisted was easily revealing the four separate main component stars of Orion's Trapezium (a feat requiring the visual acuity of the Bionic Woman).
A suspicion was confirmed as I looked through the horribly misaligned barrels. Everything had separate components.
The kaleidescopic view made me nauseous, but the excited man was perfectly content to continue with his 'bonus' abundance of stars.
true vs apparent fov...
quickie field conversions...
ft/1000yds:
example: 262 = 5.0° TFOV
(ft divided by 52.5)
m/1000m:
example: 88 = 5.0° TFOV
(m divided by 17.5)
*****
SELECTED BINOCULAR REVIEWS
Garrett Optical 20x80 UL
The Zach Attack 20x80 UL exudes both quality and elegance. One would also be hard pressed to find better packaging for their mail orders. High marks for smooth, secure mechanics and excellent field sharpness. Unbridled from its pedestal, these 80mm stallions also make for a sweet ride during casual freehand excursions.
[My fetish for freehanding big glass often gets the better of me. Mounting (or using image-stabilized) binoculars is always recommended for the steadiest image, especially at higher magnifications]
I did find two notable spec discrepancies that may or may not be specimen specific; The listed TFOV (3.2 deg) and ER (16mm) respectively measured closer to 3.0 deg and 14mm.
Neither variances were dealbreakers for me.
Fast shipping and GO's personal service accentuated this satisfying $179 transaction.
Oberwerk 20x80 Standard (vs GO 20x80UL)
Dead heat with the GO 20x80UL for performance, mechanics, FOV/ER (both still shy of spec), and
coatings. I found this interesting as the two *look* very different. At 15"/38cm, the Obie is some 3" longer with a leaner appearance. The increased length changes the ergonomics noticably but not detrimentally. After adjusting my hand placement along the barrels I find the two equally comfortable for handheld use.
Also despite the longer focal length, both binoculars show comparable field sharpness (85-90%) and daytime/lunar chromatic aberration (not fatal, but present).
Both models are highly recommended.
*****
Orion 30x80 MegaView
Out of the box, as expected, the 30s are physically very similar to Orion's 16x80 with a couple of exceptions. The slightly heavier weight (just under 6 lbs.) is a product of the center rod bracing the bino lengthwise, along with the adjustable captive weight-balancing pedestal that couples directly to a tripod. Another elegant and functional addition are the extendable thick rubber dewshields at the end of each barrel. Even when retracted they make for excellent bumpers to protect the objectives while bringing the total outside barrel diameters to 92mms. Deploying the dewshields also takes the full height of the formidable and solidly constructed instrument to 14 inches. The trademark leather-textured surface of the main body complements an efficient and attractive all black design.
The supplied hard case is nice, but the MegaView and I would feel more secure with a thick, foam-lined aluminum case to protect its crucial collimation during transport.
While the snug fit of all four eyecaps was a plus, I wouldn't trust the suprisingly thin neckstrap provided with supporting the bino's substantial bulk. (These token neckstraps are thrown in for completeness' sake. Very few people would enjoy being repeatedly jabbed in the chest with that pedestal.)
The fully-multicoated instrument reflects deep blues and greens at the business ends and
yields the perfect circles of an unobstructed light path at the lenses. The hinge, center-focus, and diopter all adjusted smoothly, securely, and with no play. I've actually come to expect this from Orion. I now own four of their binos and, if not top-of-the-line optically, their consistant mechanical quality has been very commendable. The good-sized 20mm eyepiece lenses also sport 14mms of eye relief. This is close to ideal for me, although probably a bit short for eyeglass wearers to take in the entire field.
I'm a nitpicker for collimation, and 30x binos leave little room for error, especially after a 3-day FedEx journey. So I was immensely relieved to receive these MegaViews in fine alignment. Aberration tests did reveal slight but noticable pincushioning across an otherwise very sharp (to about 80%) field. There was an expected and substantial amount of false color on high-contrast daytime objects and our moon attributed to the high magnification (for 5 bills it'd be nice if they'd spring for some apo lenses), but it was no more offensive than the inherent chromatic aberration found in some comparably fast 80mm short-tube scopes at lower powers. And for me the CA took a backseat to the increased resolution, wealth of additional stars, and depth of detail seen on Luna under the night sky.
The 50% jump in magnification from 20 to 30x seems even more significant than that noticed between 10 and 15x power binoculars. Catching our moon at the right illumination, Clavius' arched quintet of inner craters are obvious and distinct. Orion's Trapezium splits cleanly and effortlessly into its 4 major components and, while Cassini's seems just out of reach, a well-resolved Saturn presents a crisp disc and ring system. Jupiter's main belts are prominent and on the verge of showing structure. Despite their relatively small 2.7mm exit pupil and Luna's gibbous interference, the MegaViews still gathered a respectable conglomeration of stars while previewing the Double Cluster, Pleiades, M46/47, the Auriga clusters, and M35. I eagerly anticipate watching them gobble up these treasures and more under a dark sky and plan on letting them run wild thru a moonless Messier Marathon this spring. Upon receiving their Solar filters, I'm also looking forward to my enhanced views of our sun's daily activity.
While the 30x80s are advertised as having a 2.3 degree field, I could almost- but not quite- squeeze Orion's belt stars within the fieldstop yielding a more accurate and happily accepted 2.5 degree field. This yields an AFOV of 75° and is indeed one of the widest views I've experienced. The porthole effect reminds me of Naglervision (albeit without the superior field edge sharpness).
A tripod is, of course, required for unwavering views with this instrument. Any generic but heavy-duty model should work fine. My ProMaster 6600 bought at a local camera store provides more than sufficient support.
First Impressions verdict: Four out of five stars. While pricey, they are only $20 more than the 15x80MVs, solidly built, mechanically excellent, and ready to mount without an adapter. The beneficial and protective extendable dewshields are a welcome feature. It loses points for heavy CA on Luna, Jupiter and the brightest stars. But aside from the lack of color correction on those targets, the 30x80 MegaViews give rewarding and impressive binocular views of our moon, brighter planets, and the many Messier-class nightsky treasures.
*****
Glass At A Glance: Pentax 20x60 PCF WPII
$169 from amazon.com
instrument arrived promptly, well-packaged,
mechanically sound, and in fine collimation
bak4/fmc/no light path interference
dimensions 9.0x7.75"
weight 45oz/1275grams
ipd 57-72mm/ lens diameter 18mm
center focus/clickstop diopter
exit pupil 3.0mm
eye relief 18mm useable
min focus 8m
spiral clickstop eye relief adj
no eyeguards
nitrogen filled/weather resistant
very sturdy construction
sleek black rubber armored housing
tfov 2.4° (spec 2.2°)
field sharp to 95+% [comparable
to orion 15x63 mini-giants]
minimal positive distortion
afov 44° (spec)
afov 48° (adj) restricted but not necessarily a
dealbreaker. no serious tunnelvision, but more
than i'm used to.
false color: present but minimal
ergonomics: easily handheld for casual obs
(tripod is always recommended for steadiest views)
purchase motivations:
compulsive interest
comparison to 20x80s
notes: the obie 20x80 std trumps the pentax
in tfov/afov/depth of field and image brightness.
the pentax 20x60 has the edge in overall field
sharpness and color correction along with being
much smaller and lighter. the plentiful ER is overkill
to take in the smaller fieldstop perimeter but i doubt
any eyeglass wearers would complain.
tip of the day:
WP noks may be WP on the inside, but the outside
surfaces are still at the mercy of fog and condensation.
storage in a secure garage or vehicle is recommended
to keep all optics as close as possible to ambient temps
and humidity
bottom line:
five star transaction and instrument
highly recommended with caveat of
potentially restrictive tfov/afov
*as always, ymmv*
*****
Minolta 8x40 Activa WP
Cruising the net for a quality complementary wide field instrument led me to this $110 gem from the Minds of Minolta.
With BAK4 prisms and longer eye relief, the fully multicoated and weatherproof Activa series is an impressive upgrade from their venerable Deluxe (Classic) line of binoculars.
Out of the box, the all black rubber-armored Minolta is a class act, including a very nice soft-lined case and deluxe neckstrap.
Weighing in at a well-balanced 27oz., it first reminded me of a less bulky and more ergonomic version of the Orion UltraView.
The Activa's hinge, focus, and diopter adjustment (which lightly clicks into place at small increments) is smooth and secure. The caps also all fit securely. A single cover takes the place of dual lens caps.
In lieu of roll-back eyeguards, the Activa is equipped with soft rubber twist-lock eyecups to customize eye relief. Rather than spiraling freely, the eyecups again securely click into place over four incremental positions. Very handy.
I'm not a big fan of optics being shipped in a thin layer of styrofoam peanuts, but the Activa and its collimation managed to survive the UPS journey unscathed.
The very bright and vivid daytime, stellar, and Lunar images show negligable false color across nearly the entire 8.2° (spec and measured) field of view. Only the slightest pincushioning was detected over an otherwise very sharp (to 85%) field.
Noticable prism interference at the exit pupils is limited to a slight diagonal flattening at 1 o'clock (L) and 11 o'clock (R).
While the eye relief is long (spec states 18.5mm), the moderate lens recess tweaks the usable ER closer to 16mm. Wearing thin sunglasses I could still comfortably take in the entire field stop with the twist-locks fully retracted.
A generous 22mm lens diameter, interpupilary range of 58-72mm, and plenty of room to gaze around the field contributes to the comfortable eygernomics. In addition, I find the 65° apparent FOV very acceptable and immune to any tunnelvision.
Those in the market for a full featured, well-constructed, and sharp looking binocular under $150 will not be disappointed.
UNDER THE STARS
I spent an enjoyable 2 1/2 hours breaking in the 8x40 under mag 5 skies, running the latter third of the marathon Messiers and brighter NGCs.
Early impressive observations of note included the Coma cluster, Messiers 3, 5, 13, 12, 10, 4, ic4665, ngc6633, and doublestars alphaLib, epsilonLyr, nuDra, and omicronCyg.
A very pleasing tour through the Summer Triangle was highlighted by Cr399, M27, and hints of the North American and Veil nebulae. A slow, climactic cruise down the Sagittarius Arm's main drag followed through Messiers 11, 26, 16, 17, 18, 24, 23, 25, 21, 20, 8, 7, and 6. All were easily identified, resolved to various degrees, and found flowing over the expanse of about 3 binocular fields.
The Messier cottonball globulars 22, 55, 15, and 2 also stood out beyond simple detection. Uranus and Neptune were also spotted about a degree from, respectively, 4th magnitude suns lambdaAqr and iotaCap. The gas giants soon ushered in our waning crescent moon in close conjunction with Mars.
A handful of satellites and a couple of stray meteors also joined this session's festivities.
After a northeast sweep thru the rising stars of Cassiopeia and a low, early season preview of M31, the Minolta and I called it a night.
Generously rating the transparency 8/10, the Messier globs and OCs were all at least obvious while the dimmer galaxies and nebulae hid behind the early summer haze. As anticipated, the aesthetic context of a 8+° field and effortless starhopping was a fair compromise for the sacrificed brightness and resolution of my larger instruments.
As a former obsessed fuzzy hunter and long-time big bino enthusiast, this 8x session made me realize how little time I spend seeing more of the celestial forest through the trees. Always refreshing to throw a different perspective into the mix.
I would also recommend an 8x40 as an excellent first binocular for beginners learning their way around the night sky.
To sum it up: A small price for alot of field and alot of fun.
*****
Barska X-Trail 30x80
A Big Brown Truck arrived with my new toy earlier this week.
Coddled in bubble-wrap within its hard-case, the 30x Barska survived the trip without a scratch and in fine collimation...
I could stop there as, for $139, my expectations had already been met.
But as the audition progressed, I became increasingly pleased with the performance of these bargain Giants.
So here we go.
Vital Stats
Max Dimensions: 13"x9"
Weight: 4.3 lbs.
Min Focus: 49 ft.
All black, streamlined, soft and smooth rubber housing.
Extremely ergonomic and well-balanced.
Aroma: Confidential (Sorry, Kenny.)
Lifetime Limited Warranty
Mechanics: Hinge, focus, and diopter motion secure with no play. Caps all secure. Easy-to-adjust pedestal stays secure along center bar.
BAK4 Prisms (round exit pupils, no light path interference).
Coatings: MC. Despite various specs and speculation, the objectives do indeed present healthy bluish-green reflections thru its black-baffled barrels. Lens and prism paler blue reflections, however, indicate single-coatings on some surfaces.
Optics (daytime): Very bright images. Moderate pincushioning. Very well color-corrected. Minimal off-focus purple fringing.
Eygernomics
FOV: 2.1° (spec) 2.2° (measured)
AFOV: 63° (per spec) 66° (adj)
F/FSR (Field to Field-Stop Ratio): Average. No tunnelvision, but not a spacewalk either. Field-stop is well-defined.
Eye Relief: 10mm (spec) 9mm (useable. recess is slightly less than 2mm, and I'm feeling generous)
Lens diameter: 20mm
Exit Pupil: 2.7mm
IPD: 58-72mm
Comfort: Very good. Long, soft roll-back rubber eye cups.
Vignette: Minimal. Eye positioning is more forgiving than expected.
My favored useable eye relief is in the 12-14mm range, so the Barska is tighter than I prefer (any less would be painfully tight). Not recommended for eyeglass wearers, I would estimate at least a 50% loss of field.
Under The Stars
Pinpoint star images out to 75% of field.
Minimal violet fringing on Jupiter and Vega (substantially less CA than my $500 MegaView).
Main Jovian bands are distinct, showing both color and hints of texture.
Negligable false color at Luna's limb; our waning gibbous moon is splendidly detailed.
Versus Orion 30x80MegaView
For another $350, the MV provides 4mm more eye relief and a significantly larger AFOV (fieldstop is nearly peripheral). These are two important qualities for me and worth the extra cost. YMMV.
The MV also provides an additional .3° TFOV, and includes extendable dewshields.
Except for the above, the sleek and lightweight Barska 30s not only challenge the heavier MV's optics, mechanics, and quality build, but do so with better color correction (the trade-off, as expected, is increased internal reflections around the bright stuff).
Handheld Use
I spent ten straight minutes standing and another 30 on my back enjoying a relaxed freehand crawl across the available constellations. Very liberating. At just over 4 lbs, they simply do not feel like Giants.
Bino Forum edicts require me to reiterate that a tripod or IS is always recommended for more serious bino-target study.
Following that, the Barska's mounting requirements are minimal; any tripod rated for even 5 lbs will suffice.
Summary
Aside from an incurable giant bino fetish, I also wanted to occasionally share 30x binocular views with the public without putting my more valuable MV in harm's way. The Barska X-Trail 30x80 will serve this purpose with flying colors. More bang for 139 bucks than I expected.
If the MegaView drives like a Cadillac, then the Barska handles more like a sports car.
Recommended with the caveat of potentially restrictive eye relief.
*****
Glass At A Glance: Oberwerk 11x56
$99 from bigbinoculars.com
instrument arrived promptly, well-packaged,
mechanically sound, and in fine collimation
bak4/ fmc/no light path interference
height 7.75x8.0"/19.7x20.3cm
weight 36oz/965grams
ipd 56-72mm/ lens diameter 20mm
center focus/diopter
exit pupil 5.1mm
eye relief 17mm useable
min focus ~10m
soft rollback eyeguards
tfov 6.1° (spec 6.0)
field sharp to 85%
coma free field 5.5°
nominal positive distortion
afov (spec) 66°
afov (subj) v good. not a spacewalk but no
tunnelvision. fieldstop is well-defined
false color: present but minimal
ergonomics: no complaints; it's 11x at just
over two lbs. easily handheld for casual obs.
perhaps a bit large for children.
as fortune would have it, the image scale and
tfov fall about halfway between my 8s and 15s.
purchase motivations:
compulsive interest
additional outreach noks to pass around
it was kevin's turn to get my money
tip of the day:
this bino only rates a soft case. in these cases
i habitually cut and pop enough bubblewrap
to surround the bino lengthwise before sliding it
in the case for storage and transport (protection
and keeps the caps on when taking it out)
bottom line:
five star transaction and instrument
highly recommended
*as always, ymmv*
*****
Barska 15x70 X-Trail: Big Bang For The Buck
I really didn't need another binocular.
I have plenty of binoculars, actually.
Among them is a perfectly wonderful 30x80 Barska X-Trail.
But I was ready to take one for the Forum team after reading a few recent Barska horror stories, and was fully prepared to pull a broken string of parts out of the box when my 15x70XT arrived.
I found the Barska 15s on sale at Amazon for $49 and haphazardly pulled the trigger. If this negligent, impulsive purchase wouldn't get me a lemon then nothing would. *professional stuntman. do not try this at home*
Three days later a big brown truck delivered another perfectly wonderful specimen.
Well-packaged, collimated, and mechanically sound. Includes soft case, neckstrap, table tripod, adapter, and cleaning cloth.
Looks great next to its 30x big brother, too.
Vital Stats
Max Dimensions: 11"x8.5"
Weight: 2.8 lbs
Min Focus: ~50 ft
Design: All black, streamlined, soft and smooth rubber housing.
Ergonomic and well-balanced for its size. No center pedestal. Center focus.
Prisms: BAK4 (round exit pupils, no light path interference).
Coatings: Fully coated/light blue reflections at both ends
Optics (daytime): Very bright images. Very good color-correction across a flat, relatively wide FOV. Minimal pincushioning; it could actually use a little more. There's a subtle center field softness compared to my instruments with higher positive distortion.
Eygernomics (measured)
FOV: 4.4°
AFOV: 66°
F/FSR (Field to Field-Stop Ratio): Very Good. No tunnelvision, but not a spacewalk either. Field-stop is well-defined.
Lens diameter: 20mm
Exit Pupil: 4.7mm
IPD: 56-72mm
Comfort: Very Good. Long, soft roll-back rubber eye cups.
Eye Relief: 18.5mm (useable).
Vignette: Minimal. However, without eyeglasses the eyeguards must be extended to achieve the proper viewing distance. I always leave the eyeguards extended anyway and take this in stride, but it may be more important to others.
Under The Stars
Pinpoint star images out to 80% of field.
Negligable false color at Luna's limb. Our waning gibbous moon is splendidly detailed and star colors are vivid. The Pleiades, Double Cluster, and Orion Nebula are beautifully framed.
Versus 15x63 Orion MG
I'm not quite comparing apples to apples here.
Both have comparably long eye relief and pleasing eygernomics.
Both also provide comparable brightness; the Barska's extra aperture
helps compensate for the Orion's better coatings/contrast (the XT's exit pupil is also a half-millimeter larger).
The Orion is much lighter, more compact, and has the edge in ergonomics, while the larger and heavier Barska provides an extra .5° FOV.
The Orion shows almost no internal reflections (FMC) but an increase in chromatic aberration on Luna and the brightest stars/planets.
These trade-offs all come down to personal preference.
Handheld Use
Weighing-in at less than 3 lbs, I manually swept the night sky standing for a half-hour before even realizing that I'd manually swept the night sky standing for a half-hour. A very liberating and enjoyable ride.
The Barska's mounting requirements are minimal; any tripod rated for even 5 lbs will suffice.
Summary
My best mid-power bino investment for the price.
For those that can handle occasional internal reflections better than false color, I would easily consider the Barska 15x70XT as one of the best mid-power instruments available under $100.
And a steal at $49.
Highly recommended with the standing caveat to buy from a reputable dealer that will personally check the mechanics and collimation prior to shipping. Buy and test locally if possible.
*****
[as good of place as any to put this. enjoy.]
Observing Under the Influence: The Apogee 18x50 Beer Bottle Telescope
I got the sweetest lil' early stocking-stuffer for this Christmas.
Apogee's famed, novelty 18x50 BBT .
I'm having a blast with it.
The following may or may not be considered my review.
Vital Stats
Primary Mirror: 50mm
Magnification: 18x (fixed)
Focal Length, Ratio: 235mm, f/4.7
Max Dimensions: 8.5" x 2.5"
Weight: 10 oz.
Min Focus: 8 ft.
Price: $21.95
Apogee Transaction Rating: 4/5. Prompt delivery and good communication.
Despite arriving undamaged, the inner packing did not surround the product.
Out-Of-Box: Very nice heavy-nylon black case. Includes shoulder strap
and cleaning cloth. The scope is green (I haven't decided which shade yet),
more rugged than expected, and, coincidentally, shaped like a beer bottle- including the eyelens cap which pops on and off. A dribble-hole along the main tube doubles as a quarter-inch adaptee for possible tripod mounting.
Coatings: Fully Coated optics (decent blue tint from each end).
Eygernomics: In this specimen, the field of view is a pleasantly-flat, correct-image 3.5°, and coma-free out to 75%. No on-axis astigmatism detected. Negligable false color. Nominal pincushioning. Exit pupil is 2.7mm. Apparent field is an adequate 63°; Fieldstop is sharp. No tunnelvision, but not a spacewalk either.
But you have to get *to* the FOV first.
I found the 5mm lens recess to yield a useable eye relief of about 5mm. In addition, the eyelens diameter is a mere 12mm. This inconvenience is only offset by the lack of an eyeguard and ability to shove the tapered neck right into your eyeball.
Ergonomics: About what you'd expect. It's about as comfortable as holding an empty beer bottle up to your eye can be. Using both hands and adopting a Master and Commander pose is almost irresistable.
Will I Look Silly Using It: Not if you're alone. At night.
But seriously, most folks would probably just pity what would appear to be a pathetic drinking problem. Add an eyepatch (to view comfortably with both eyes open) and passersby might start charitably tossing coins at you as well.
Will I Feel Silly Using It: There's a good possibility ("But I don't wanna be a pirate..."). Using the BBT is kinda like owning a moped; fun to ride, but you don't want your friends to see you with one.
Mechanics: The secure caps are made of hard plastic. The smooth and secure focusing is attained by rotating the top half of the bottleneck.
That's about it for mechanics.
Nothing rattling around inside.
The velcro on the cool, black case also performs admirably.
Mounted on an EQ2, my only complaint was having to listen as my nearby StarMax was laughing its aperture off.
Storage: In its cool, black case. The mini-scope doesn't match anything in the house. Did I mention the weird shade of green?
Viewing from a dark, transparent sky is, of course, recommended- and does alot to compensate for the lack of aperture and relatively small exit pupil.
The BBT also tests ones true starhopping mettle. At 18x, it's a shaky handheld ride until you put in some practice. I happen to love the challenge, and even plan on competing in next spring's Marathon with it. Alone. Stay tuned.
For a $20 novelty astro-gift, the Apogee Beer Bottle Telescope actually has
alot to offer as a practical stargazing instrument.
I can only hope the already-suspicious Illinois State Police that frequent my favorite rural site show the same appreciation (after I'm forced to take a breathalyzer test).
Happy hunting, and Cheers.
*****
Glass At A Glance: Zhumell 20x80
$99 from binoculars.com
instrument arrived promptly, well-packaged,
mechanically sound, and in fine collimation
hard liner in leather case
bak4/fmc (spec). this specimen is a
tongue-in-cheek fmc; multicoated obj/fully
coated prisms and lens
no light path interference
height 13"x9"/33cmx23cm
weight 4.4lbs/2.0kg
ipd 56-72mm/ lens diameter 20mm
exit pupil 4.0mm
eye relief 16mm useable
min focus ~20m
center focus/pedestal/center brace
soft rollback eyeguards
tfov 3.2° (spec 3.2°)
field sharp to 75%
coma free field 2.5°
negligible positive distortion (just this side of neutral)
afov (spec) 64°
afov (subj) no tunnelvision but not as panoramic
as spec might suggest. fieldstop is well-defined
false color: present but minimal
ergonomics: handholdable for casual use and hotdogging at star parties, but tripod is recommended (any standard camera/video tripod will suffice).
purchase motivations:
see what all the fuss is about
second Z20x80 subsequently purchased as
donation to local astroclub's rental program
tip of the day:
along with ideally helping preserve collimation, the
lengthwise bar on crossbraced models can be held as a vertical support for freehand viewing (sliding the pedestal all the way forward). the opposite hand steadies the horizontal and controls focus. the bar also makes a convenient carrying handle for out-of-case transport
bottom line:
five star transaction/four star instrument
recommended bang for the buck purchase
weak afov and outer field sharpness compared to
the obie and garrett counterparts but still qualifies
as an adequate instrument for general stargazing.
*as always ymmv*
[note: the barska 20x80xt auditioned rates a nearly identical review. also see 'a tale of four 20s']
*****
Orion 15x63: A Mini-(Giant) Revelation
I'd lugged my 16x80s around for over 10 years.
Freehand or mounted, I'd never given a second thought to their >5 lb. mass. In fact, I'd always related the healthy bulk of these giants as a sign of their powerful optics and construction.
So my first thought upon hefting the mere 41 ounces of the Mini-Giants from their hardcase was, "Are they serious?"
They are.
The relatively light weight is nicely balanced along an 8 3/8" sleek and streamlined body. (Actually, the Mini-Giant series appears to be the revamped FMC big brothers to the popular Orion Scenix line of binoculars.)
As advertised, they are easily hand-holdable for several minutes at a time. Although tripod-adaptable, I doubt I would ever have to use them mounted.
Still suspicious, I thought there must be some trade-off (specifically, prism interference) to this contoured design. But there was none. Full circles of light greeted me at the lenses and not a millimeter of obstruction was present while gazing down the black-baffled barrels of this fully multi-coated instrument.
The hinge, focuser, and diopter adjustments all moved smoothly and securely with no play, and, although I'm very sensitive to collimation, I still slowly alternated closing and opening each eye to find the merged image in perfect alignment.
Aberration tests also showed no excessive pincushion or barrel-effect across the 3.9° (measured) field, and color-correction is confined to minimal slivers of green and red on high-contrast daytime objects and Luna.
I've never put too much faith in AFOV specs, and the MG is a good example why. A pleasantly wide apparent field belies the modest 58° (adj) quotient. Serious field distortion/coma is limited to the outer 5% of the field, and only really noticable if you go looking for it.
There is no lunar ghosting, and our moon's entire terminator is sharp with detail. The Orion Nebula, Pleiades, and Double-Cluster are all amply framed with pinpoint star images. All very impressive.
I just kept waiting for 'the trade-off' and, aside from losing 17mm of aperture and half the weight of my 16x80s, found none.
For nitpickers, I should mention that the 4.2mm exit pupil and design does not allow a lot of leeway for eye movement at the lens without some vignetting. But then, most higher-power binos are selected for close-up on-axis work as opposed to eyeballing-around wide panoramic fields.
Also, as advertised, the 15x63s have plenty of eye relief (18mm useable). Highly recommended for eyeglass wearers. However, without glasses, the eyeguards must be extended to achieve the proper viewing distance. I always leave the eyeguards extended anyway, and can live with this, but it may be more important to others.
Again, I'd lugged my 16x80s around for over 10 years.
They've been with me through 30 states, Canada, Mexico, and the Caribbean. They've witnessed many comets, occultations, and eclipses over their lifetime. Mounted, they've impressed hundreds of starparty guests and friends with their size, power, and optics.
They rock.
And I would never let them go.
And they will always remain mounted near my scope for public viewing.
And I'm not just saying this because they're giving me the evil-eye while I'm writing this.
Nevertheless, in summary, I recommend the excellent optics and lightweight ergonomics of the Orion 15x63s (at around $200) as a competitively-priced alternative to many of the much heavier and tripod-dependent giant binoculars in this magnification range.
*****
| Articles |
[sigmaOri courtesy of DSS]
Given a visual acuity (VA) of 150" a 10x binocular will potentially split doublestars with separations as close as 15" (150/10), and 5" at 30x.
Doubles with equal or near equal mags are easier to blackline than those with a significantly brighter glare from the primary.
Color interpretations are often subjective for several reasons including sky conditions, color sensitivity, contrast effects, and aperture.
Equally impressive in low power scopefields, this collection of brighter targets for northern observers is arranged by constellation and decreasing separation. Pocket Sky Atlas chart references are included.
Andromeda psa 2/3
56 0156+3715 5.7, 6.0 @ 190"
59 0211+3902 6.5, 7.0 @ 16.6"
gamma 0204+4220 2.3, 5.5 @ 9.8"
stf79 0100+4443 6.0, 7.0 @ 7.8"
Aquarius psa 76
94 2319-1327 5.3, 7.3 @ 13"
107 2346-1840 5.5, 6.5 @ 6.6"
Aquila psa 65/66/67
15 1905-0402 5.5, 7.2 @ 38"
57 1955-0814 5.8, 6.5 @ 36"
stf2654 2015-0330 6.0, 7.5 @ 14.2"
5 1847-0057 5.5, 7.5 @ 13"
Aries psa 4
30 0237+2439 6.6, 7.4 @ 38.6"
lambda 0158+2336 4.9, 7.7 @ 37"
gamma 0154+1918 4.8, 4.8 @ 7.8"
Auriga psa 12
stf698 0525+3451 6.5, 7.5 @ 31.2"
stf764 0541+2929 6.5, 7.0 @ 26"
14 0515+3231 5.1, 7.4 @ 14.6"
stf872 0616+3609 6.9, 7.9 @ 11.3"
41 0612+4843 5.0, 7.0 @ 7.7"
stf918 0634+5227 6.5, 7.5 @ 4.7"
Bootes psa 42/44/53
mu 1525+3723 4.3, 6.5 @ 108"
s656 1350+2117 6.8, 7.3 @ 86"
iota 1416+5122 4.9, 7.5 @ 38"
stf1850 1429+2817 6.0, 7.0 @ 25.6"
kappa 1414+5147 4.6, 6.6 @ 13.4"
xi 1451+1906 4.7, 7.0 @ 6.9"
stf1835 1423+0827 5.1, 7.6 @ 6.2"
pi 1441+1625 4.9, 5.8 @ 5.6"
Camelopardalis psa 11/12/31
11/12 0506+5858 5.4, 6.5 @ 180"
s436 0349+5707 6.5, 7.3 @ 58"
32 1249+8325 5.3, 5.8 @ 21.6"
1 0432+5355 5.7, 6.8 @ 10.3"
Cancer psa 24
b584 0840+1933 6.9, 7.2 @ 45"
iota 0847+2846 4.2, 6.6 @ 30"
stf1245 0836+0637 6.0, 7.2 @ 10.3"
zeta 0812+1739 5.6, 6.0 @ 5.9"
phi2 0827+2656 6.3, 6.3 @ 5.1"
Canes Venatici psa 32
17 1310+3830 6.0, 6.2 @ 84"
alpha 1256+3819 2.9, 5.5 @ 19.4"
Canis Major psa 27
h3945 0717-2320 5.0, 5.8 @ 26.8"
Capricornus psa 66
beta1/2 2021-1447 3.4, 6.2 @ 205"
omicron 2030-1834 6.0, 6.5 @ 21.9"
Cassiopeia psa 1
oss26 0220+6002 6.9, 7.4 @ 63"
stf3053 0003+6605 6.0, 7.7 @ 15.2"
eta 0049+5749 3.4, 7.5 @ 12"
Cepheus psa 71/73
delta 2229+5825 3.9, 6.3 @ 41"
stf2840 2152+5547 5.5, 7.3 @ 18.3"
beta 2129+7034 3.2, 7.9 @ 13.3"
xi 2204+6438 4.4, 6.5 @ 7.7"
stf2816 2139+5729 5.6, 7.7, 7.8 @ 11.7", 121"
Cetus psa 6
66 0213-0224 5.7, 7.5 @ 16.5"
Coma Berenices psa 45
17 1229+2555 5.3, 6.6 @ 145"
32/33 1252+1704 6.3, 6.7 @ 95"
24 1235+1823 5.2, 6.7 @ 20.3"
Corona Borealis psa 53
zeta 1539+3638 5.1, 6.0 @ 6.3"
sigma 1615+3352 5.6, 6.6 @ 6.2"
Corvus psa 47
stf 1669 1241-1300 6.0, 6.1 @ 5.4"
Cygnus psa 62/63
31 2014+4644 3.8, 7.0, 4.8 @ 107", 338"
16 1942+5031 6.0, 6.2 @ 40.0"
beta 1931+2758 3.1, 5.1 @ 34.4"
61 2107+3845 5.2, 6.0 @ 28"
stf2486 1912+4951 6.6, 6.8 @ 7.9"
Delphinus psa 64
s752 2030+1925 6.6, 7.0 @ 106"
gamma 2047+1607 4.4, 5.0 @ 9.1"
Draco psa 41/52/61
16/17 1636+5255 5.4, 5.5 @ 108"
39 1824+5848 5.0, 7.4 @ 89"
oss123 1327+6444 6.7, 7.0 @ 69"
nu 1732+5511 4.9, 4.9 @ 62"
omicron 1851+5923 4.8, 7.8 @ 34.2"
psi 1742+7209 4.9, 6.1 @ 30.3"
40/41 1800+8000 5.7, 6.1 @ 19.3"
stf2452 1854+7546 6.6, 7.4 @ 5.6"
Equuleus psa 75
epsilon 2059+0418 6.0, 7.1 @ 11"
Eridanis psa 16/17
55 0444-0848 6.7, 6.8 @ 9.2"
32 0354-0257 4.7, 6.2 @ 6.8"
Gemini psa 25
20 0632+1747 6.3, 6.9 @ 20.0"
38 0655+1311 4.7, 7.7 @ 7.1"
Hercules psa 52/54/55/65
37 1641+0413 5.8, 7.0 @ 70"
kappa 1608+1703 5.3, 6.5 @ 28"
100 1808+2606 5.9, 6.0 @ 14.2"
95 1802+2136 5.0, 5.1 @ 6.3"
alpha 1715+1423 3.5, 5.4 @ 4.7"
rho 1724+3709 4.6, 5.6 @ 4.1"
Lacerta psa 72
8 2236+3938 5.7, 6.5 22.4"
Leo psa 34/35
alpha 1008+1158 1.4, 7.7 @ 177"
tau 1128+0251 5.0, 7.4 @ 91"
83 1127+0300 6.2, 7.8 @ 28.5"
54 1056+2445 4.5, 6.3 @ 6.5"
gamma 1020+1951 2.2, 3.5 @ 4.4"
Lepus psa 16
gamma 0545-2227 3.7, 6.3 @ 96"
h3780 0539-1751 6, 9, 8, 8 @ 89", 76", 129"
s476 0519-1831 6.2, 6.4 @ 39"
Libra psa 57
alpha 1451-1602 3.0, 5.0 @ 231"
shj179 1426-1958 6.6, 6.6 @ 16"
stf1962 1539-0847 6.5, 6.6 @ 11.9"
Lynx psa 23
5 0627+5825 5.3, 7.9 @ 96"
19 0723+5517 5.6, 6.5 @ 14.8"
stf958 0648+5542 6.3, 6.3 @ 4.8"
Lyra psa 63
epsilon1/2 1844+3940 5.0, 5.2 @ 208"
beta 1850+2948 3.5, 7.0 @ 46.6"
oss525 1855+3358 6.0, 7.7 @ 45"
zeta 1845+3736 4.3, 5.9 @ 44"
Monoceros psa 25/26/27
zeta 0809-0259 4.3, 7.8 @ 67"
epsilon 0624+0436 4.5, 6.5 @ 27"
beta 0629-0702 4.7, 5.2 @ 7.3"
Ophiuchus psa 54/56
rho 1626-2327 5, 8, 7 @ 151", 156"
s694 1752+0107 6.9, 7.1 @ 82"
53 1735+0935 5.5, 7.5 @ 41.3"
61 1745+0235 6.2, 6.6 @ 20.6"
Orion psa 14/16
delta 0532-0018 2.5, 6.5 @ 52.6"
theta2 0535-0525 5.0, 6.5 @ 52"
shj49 0459+1432 6.0, 7.5 @ 39.4"
stf747 0535-0600 4.8, 5.7 @ 35.7"
23 0523+0333 5.0, 7.1 @ 32"
stf855 0609-0230 6.0, 7.0 @ 29.5"
sigma 0539-0236 4.0, 8.8, 6.5, 6.6 @ 11", 13", 42"
iota 0536-0555 2.8, 6.9 @ 11.3"
theta1 0535-0523 6.7, 7.9, 5.1, 6.7 @ 8.8", 13.0", 21.5"
lambda 0535+0956 3.6, 5.5 @ 4.4"
Pegusus psa 74/75
stf2841 2154+1943 6.4, 7.9 @ 22.3"
stf2978 2308+3249 6.3, 7.5 @ 8.4"
Perseus psa 12/13
57 0433+4304 6.1, 6.8 @ 116"
stf331 0301+5221 5.3, 6.7 @ 12.1"
Pisces psa 5
77 0106+0455 6.8, 7.6 @ 33"
psi1 0106+2128 5.6, 5.8 @ 30"
zeta 0114+0735 5.6, 6.5 @ 23"
35 0015+0849 6.0, 7.6 @ 11.6"
65 0050+2743 6.3, 6.3 @ 4.4"
Sagitta psa 64
bu139 1913+1651 6.5, 7.5 @ 113"
theta 2010+2055 6.5, 7.4 @ 84"
Scorpius psa 56
nu 1612-1928 4.3, 6.4 @ 41"
beta 1605-1948 2.5, 5.0 @ 13.7"
xi 1604-1122 4.8, 7.3 @ 7.6"
Serpens psa 55/65
stf1919 1513+1918 6.7, 7.6 @ 23.9"
theta 1856+0412 4.6, 4.9 @ 22.1"
Sextans psa 34
35 1043+0445 6.3, 7.4 @ 6.8"
Taurus psa 14/15
21/22 0346+2432 5.6, 6.4 @ 168"
eta 0348+2406 2.9, 6.3 @ 117"
hvi98 0416+0611 6.3, 7.0 @ 66"
chi 0423+2538 5.5, 7.6 @ 19.4"
stf401 0331+2734 6.4, 6.9 @ 11.3"
118 0529+2509 5.8, 6.6 @ 4.8"
Ursa Major psa 31/42/43
stf1831 1416+5643 6.6, 7.1 @ 108"
65 1155+4629 6.5, 6.7 @ 63"
stf1415 1018+7104 6.7, 7.3 @ 16.7"
zeta 1324+5456 2.3, 4.0 @ 14.4"
Ursa Minor psa 51
alpha 0231+8915 2.0, 9.0 @ 18.4"
pi1 1529+8027 6.6, 7.3 @ 31"
Virgo psa 47
stf1627 1218-0357 6.6, 6.9 @ 20.1"
54 1314-1849 6.5, 7.2 @ 5.3"
Vulpecula psa 75
stf2769 2111+2409 6.5, 7.5 @ 17.9"
*****
| Double Stars |
How many are already cringing at the mere mention of the word astrologer?
It's almost a gag reflex for some of us. But then, amateur astronomers are practically bred to criticize all things astrologic, and to discourage others from following that blasphemous starpath.
I've certainly done more than my fair share of astrology-bashing (Saber's Fractured Horoscopes is probably still floating around the internet somewhere).
So while it is certainly not my intention to leave readers with a grudging admiration of astrology and its practitioners, I would like to share some accumulated- albeit hard to swallow- perspectives regarding them.
Astrologers used to have one of the best gigs in town. Before telescopes came along, they were considered experts in philosophy, theology, and psychology, as well as masters of the stars. But the problem with being held in such high regard was that they eventually became the scapegoats for the kings' and emperors' bad decisions. This usually meant death or exile, causing many to shy away from professional astrology as a career goal. Still, there seemed to be marked personality characteristics common to different individuals whether it had to do with the stars or not. People continued to explore this, although they would never again bet their lives on it.
Meanwhile, in attempts to explain or disprove the correlation between heavenly bodies and Earthly existence, critical stargazers were noticing discrepancies in the movement of Sol and Luna among the other points of light in the sky. Made aware of these compounding eccentricities, even kings realized that the sky's motion was no longer a viable way to plan their day- much less start a war or run an empire.
Galileo may have turned the world on its ear with his Jovian observations, but he also made it chic to discover new facts about the stars and their motions. And although astrologers had already named most of the constellations and bright stars, the newly motivated astronomers continued using the already familiar terms. Ironically, this shared terminology is pretty much the reason many grit their teeth at astrology. And except for the shared terminology modern astrology and astronomy are totally different animals. They just happened to have been born in the same celestial jungle.
Astrology's relation to the physical universe is purely symbolic. Horoscopes and starsigns, for example, don't allow for precession. I used to joke that the Head Astrologers were simply lazy, and content to wait 13,000 years for the silly ecliptic to realign itself. In actuality, they simply don't care. It's not even fundamental to their pursuit. Horoscopes themselves, like fortune cookies, almost always give vague but sensible, positive advice. Accuracy is only rated by how well it helps one get through their life.
Also, there is no bad publicity. Without astrology and daily horoscopes in thousands of newspapers, how much media attention would the constellations and star-stuff get? Not much except for the occasional Pluto Status Update and some new planet pics every couple of years. Maybe we should instead be thanking astrologers for their misguided but prolific advertising.
While I admire the passionate and thorough spanking Phil Platt (of Bad Astronomy) gives astrology, I've nevertheless conceded two practical- if peripheral- benefits of horoscopes; It's often a daily reminder of- and many people's first exposure to- astronomical terms. And the 12 classic zodiac constellations are usually at least listed in proper order. Good reinforcement for learning ones way around the ecliptic.
Realizing or wanting to realize these astronomy-based benefits is another matter.
As a veteran starparty host, I've also found that astrology fans are some of the most appreciative guests at ones scope, assuming they're not scoffed at once they reveal their own stellar connection.
Lastly, any animosity toward astrology, or anything so innocent in life, only takes up that many more brain cells that could be used to enjoy ones own pursuits and passions. Especially the stars.
And if I've offended anyone over the course of this article I apologize. Unfortunately it's in my nature. I am, after all, a Scorpio.
Stephen Saber does not practice astrology, but defends its existence.
He curses the clouds from his home in Rock Island, Illinois.
*****
| Articles |
Jack and Jill went up to our moon to fetch a pail of water.
(After breaking his crown and her tumbling after they both got really weird.)
Jill set off to search the far side, while Jack was to take the pail and scout the near side.
Quite suddenly, Jack ran into Luna's only other inhabitant, the Mutant Beaver.
Formerly representing the constellation Beavius (now occupied by the Pleiades), the Mutant Beaver had been forever banished to our moon by Cepheus for gnawing on Perseus' ankle during his fight with Cetus to save the lovely Andromeda.
Finally having someone to talk to, the Mutant Beaver refuses to let Jack pass until he's heard every silly astronomy joke he's been making up during his exile.
Jack, to this day, endures the Mutant Beaver's ramblings.
Jill was last reported near the crater H.G. Wells.
Stephen Saber is an Astronomical League Master Observer and author of the 'Starhoppers Guide to the Herschel 400'.
He curses the clouds from his home in Rock Island, Illinois.
Watch for the children's book Saber's Fractured Astro Mythology coming soon.
*****
| Outreach |
