Plossls in the 25 mm - 32 mm range work well. However, if you go any
longer than 32 mm, the eye relief becomes too long and you may get seasick.
The 19 mm Panoptics are probably the best binoviewing eyepieces I've ever
used. If your scope has a focal length shorter than about 2,000 mm and you
don't need to use a barlow, better figure on getting a pair. The 15 mm Pan-
optics work well, too.
I have had trouble getting the TeleVue Radians to work on this binoviewer
(they are too long and sit up too high off the binoviewer unit.) However, one
reader tells me the Radians do work in the TeleVue unit. Update, 3/10/00:
I am told that a mechanical device, currently under contruction, will allow
use of the Radians on this AP/Zeiss unit.
Hot tip: The 25 mm and 18 mm University Optics orthoscopics are some of
the best binoviewing eyepieces out there, and they're cheap to boot.
As you get down to the 12 mm range, it becomes hard for many people to
merge the images. Try before you buy.
10) Finally, if it isn't obvious, you are taking the aperture of your scope and
sending one-half of its light gathering ability to each eye. Expect dimmer
views. This is not quite as bad as it sounds, as the reduced eyestrain seems
to make up for this a little.
It is important that you have all of this worked out in your mind before laying
down the big bucks to enter binoviewer-land. Once you have all the bugs worked
out, you will be rewarded with stunning views. The first time I got it right, I didn't
want to leave the eyepiece. Deep sky objects look three dimensional, and the
reduced eyestrain means less viewer fatigue during the observing session. You
stay out longer, and see more as a result.
If I had to rank scopes, I'd say that the best candidates for binoviewers are nice
refractors like the ones from AP, Takahashi, TeleVue, the TMBs, and the better
Vixens. Next come the big truss Dobs, and then the rest. But there are excep-
tions to this, of course. Good luck, and proceed carefully!
4) Takahashi Sky Patrol II Equatorial Mount
(Mount, DC RA drive, corrector wand, about $700)
The Sky Patrol II is the smallest equatorial mount in the Takahashi line, and
possibly the smallest eq mount in existence. It is incredibly cute, and will
fit into the palm of your hand. Although it seems designed as a tracking
mount for a small camera, you can also attach a small scope to it.
The Sky Patrol II, Holding an FC60
This mount arrived from the dealer as a bag of small green metal parts. The
owner invited me over to help him assemble it. We both stood there for a few
minutes staring at the bag of parts, scratching our heads, having no idea how
it would become an equatorial mount. The instructions were in Japanese and
were of little help. I was beginning to think that "Sky Patrol" was Japanese
for "Mysterious Bag of Green Metal Parts."
Slowly, over the course of ten minutes or so, our confusion gave way to
understanding (ie, "So THAT'S why that bolt is shaped that way!") Then,
our understanding gave way to wide grins. Pretty soon we were laughing
like little children. It is very difficult to describe this in writing, but this
mount is absolutely ingenious in its engineering and execution. I had
a hankering to take it apart just so we could put it together again.
Like any Takahashi mount, the drive (which runs on four "D" cells) is so
quiet you may not even hear the motor running even with your ear pressed
against the housing. There is a nifty little wand that you can use for RA
The mount attaches to a photo tripod. It's tiny, so don't try and use it on
anything larger than a Ranger-sized scope (the counterweight is a mere
1 lb.) Tracking is accurate and totally silent. Ironically, I found the mount's
biggest feature -its light weight- to be its biggest problem as well. Your rig
will be so light that if you so much as bump your scope the wrong way, you
will have to realign the whole mount. This happened several times during
Do you need a Takahashi Sky Patrol II mount? I find its design and construc-
tion to be brilliant, and tinkerers will want to play with it to see how it works.
If you need a platform for tracking a camera, I know of no better product
than this one. However, visually, I felt I would have been just as happy to
use the FC60 on a photo tripod, without all the knobs, batteries, etc. Older
versions are called simply "Sky Patrol."
Recommended if you must have the smallest equatorial mount possible.
Even if you don't buy one, try and get a look at one sometime.
5) Collins I3 Image Intensified Eyepiece
($1995, 25 mm or 15 mm TeleVue eyepeice, 2" version available)
"Dan, come here...NOW."
I was looking at M82 through this eyepiece, up on the ladder with the 20"
Obsession at a recent informal sky watch amoung friends. I could see detail,
mottling, and incredible extension. The galaxy careened out of the field
of view at both ends. Furthermore, there were so many background stars,
you could have fooled me into thinking that I was looking through the Milky
An Electronic Miracle?
The Collins I3 Piece
OK, I've read the ads for this device, and so have you. Using military-grade
night-vision technology (the instructions warn you not to take it outside the
US) and TeleVue optics, the Collins Image Intensified Eyepiece promises
to turn your 6" telescope into a 20" (or your 2.4" into a 10", etc) with the
twist of a switch.
I received this Collins I3 Piece as a review sample from Rivers Camera, a
local telescope dealer and occasional Saturday morning hangout location
for our local club. You have them to thank for this review. Four observers
lent their eyes over the course of a week and contributed their comments
It took me a while to get used to the quirks of this device. Before I go on,
there are a few things you should know.
1) First and foremost, you will have one big problem with this device, and
I can summarize it in one word: FOCUS. I tried the eyepiece in several
scopes - the Pronto, the Traveler, a 6" Sovietski review sample that I had
on loan, the 10" Starmaster EL, and the 20" Obsession. Of these, ONLY
the Traveler had enough in-travel to find focus.
The Collins needs so much in-travel on the focuser, I began to treat it
like a binoviewer in this regard. As such, interposing a barlow works. I
have not seen this fact mentioned in any other review of this product: unless
you own a nice refractor, or other scope with a large amount of focus travel,
you may not be able to find focus at all without the use of a barlow. However,
once you insert the barlow, any telescope should find focus. I did not try it
in an SCT; anyone out there want to enlighten me on the SCT-focus issue
with this product?
...as if this wasn't bad enough, there is a second adjustment to contend
with. On the top of the eyepiece, there is a threaded barrel that holds
the eye lens. After focusing your scope, you may find that the images
still aren't sharp. If so, you need to screw/unscrew this barrel to sharp-
en up the images. Apparently the Collins depends in part on the variable
distance between its eye lens and its field lens to do its thing.
Of the four people who used this device while I had it, we needed four
totally different positions on this barrel. This was a bit of a pain when
we wanted to share views. Finally, there is no stop at the end of the
barrel's travel, so you are always in danger of unscrewing the eyepiece
completely in the dark, with the requisite consequences.
Collins Responds, 4/5/00: According to Bill Collins, the I3 Piece is
offered in the 2" version with a remote-mounted battery pack, a setup
which allows you to slide the entire eyepiece much closer to the objective.
Collins says they always ascertain what kind of scopes their customers
use, and recommend a model accordingly. Also, Collins reports that
most SCTs will reach focus without a barlow.
2) The image you see is green. This sounds like a big deal, but it isn't.
You get used to it pretty quick. However, it will ruin your night vision a
3) The image you see is erect (non-inverted.)
4) There is some background noise (ie green haze.) The darker your
skies, the more subdued this gets. The I3 Piece amplifies ALL light,
so if people are walking around with flashlights, etc, the I3 Piece will
amplify it and send it right into your eye.
5) Images are not quite as sharp with the eyepiece in place. There is
also some curvature of field and elongated star images near the edges.
6) The field of view on the 25 mm model is very narrow, around 40 degrees.
I did not try the 15 mm version. Users can change between focal lengths
for about $225. There is also a 2" version (also not tried.)
7) The Collins works best on clusters, galaxies, globulars, and emission
nebulae. It does not work particularly well on reflection nebulae. The
eyepiece is more sensitive towards the red area of the spectrum.
8) The life of the device is rated at 10,000 hours.
9) You are cautioned not to use the device on objects greater than 2nd
magnitude (this includes planets and the moon.) On 5th magnitude and
brighter objects, there is a green halo around the airy disc.
Having said all this, the device works, and works very well. Images of M81/
M82 and M42 in the 2.7" Pronto went deeper, and with greater extension,
than in the 10" Starmaster. NGC2158, the little cluster next to M35, was
nearly resolved in the Pronto at 19X. Ditto for NGC1907 next to M38.
Amazing. However, the Zambuto mirror in the Starmaster was sharper,
and sharper by a long way.
The Traveler gave nice views, and went modestly deeper than the 10" Star-
master. It was nice to ditch the barlow for a change. The 25 mm eyepiece
will just barely frame M81 and M82 in the same field of view. However,
with the galaxies at the edges, the view was not terribly pleasing. This
prompted one observer to state that the Collins gives you quantity, but
at the expense of quality.
Get used to seeing your I3 Piece this way
(Barlow: TeleVue 1.8X)
Moving up to the 10", the Collins took the Starmaster deeper than the 20"
Obsession. One observer present reflected that the I3 Piece allows space-
cramped observers to immediately own a bigger telescope without the added
bulk. Views of M81 and M82 in the 10" rivaled or exceeded that of the
naturally-aspirated 20" Obsession.
We moved up to the 20". Wow. I could see dust lanes in tiny NGC3190
in Leo (I didn't think it was possible for an amateur telescope to see this.)
M65 looks like the Andromeda Galaxy through an 8" SCT. The aforemen-
tioned NGC2158 looks like M35 through an 8" reflector. NGC2903 filled
the eyepiece. I had the best views ever, I think, of M82 with the Collins-
Obsession combination. I would ballpark the 20"'s ability, with the I3
Piece in place as being close to a telescope with a 40"-50" mirror.
As a reality check, I used all of the scopes "naturally aspirated" afterwards.
It felt like I was wearing sunglasses. The magnitude of the image intensifica-
tion sneaks up on you; you don't realize how much gain you're actually getting
until the device is gone. I should point out that while sweeping the Milky Way
region around Monoceros in the Traveler, I found stuff that isn't plotted in
Uranometria. In the 20", I was seeing all sorts of unidentified "mystery"
stuff that I couldn't find plotted anywhere.
There are some things the I3 Piece didn't do well, and some of this is
baffling. Thor's Helmet was invisible, despite technically being an
emission nebula, and the Owl Nebula (M97) was no better with the Collins
than without it. Other scopes present had no problem finding Thor's Helmet
using the customary OIII filter. There was little to be gained on the Eskimo
Nebula, and the Collins wouldn't show Hind's Variable Nebula at all even in
It took me a while to get used to this device. I didn't like it at all the first
night I had it. As the week drew on, however, my opinion of it steadily
rose, and I began to look forward to using it. I also became a popular
guy around here when word got out that I had it. Is it worth $2000? Who
knows? For those interested in it, I would say a personal audition is
mandatory. Unfortunately, given the price, Collins isn't exactly selling
them like hotcakes, so there aren't many of them out there to sample.
If people don't sample them and buy them, the price won't come down.
A nasty Catch-22!
Finally, there is an issue with obsolescence. Our Brave New World of high
tech, high zoot toys seems to change and get better monthly. Is there
another, better (and cheaper) version of this product just down the road?
Recommended for the astronomer who has everything. This isn't exactly
something you save up for; you either have the money for it or you don't.
But if someone in your local observing group gets one, do not miss the
opportunity to look through it. You may just wind up with one after seeing
Collins I3 Piece Hots:
Instant 2X-3X aperture gain without any added bulk
A godsend for galaxy hunters
Makes you instantly popular among your local group
Collins I3 Piece Nots:
Issues with focus, sharpness, and background noise
Possible issues with technological obsolescence and resale value
Makes you instantly popular among your local group
A great toy for those who must have the latest gadget...and who must
have it now.
6) Dan Mounsey's Custom Astro Cases
(Various sizes and prices, check Dan Mounsey's web site)
You've probably seen the ads on my "links" page for these astro cases. Dan
Mounsey builds these wooden cases to exacting standards and finishes them
I usually try to include a photo of all the products reviewed here, but this
is one instance where I hesitated to do so. There is no way the image above
can convey the beauty and craftsmanship of the case. You have to see it,
run your hand across the mirror-smooth glossy finish, see the quality of
the brass hardware and the tight tolerances on the cuts, to fully appreciate
Mounsey can custom tailer a case for your scope, eyepiece collection, or
accessories; just give him your requirements and a little time. I had one
made for my Takahashi FS102 and the build quality was so good I wound
up displaying the case in my living room. About the only criticism I have
is that the cases are so nice, you might be a little hesitant to use one
in the field.
Other than this (minor) concern, the cases are very highly recommended.
Various Reviews, Page 6
By Ed Ting
1) Starlight Nights (book)
2) Box of Expensive Eyepieces from Markus Ludes/ APM
3) AP/Zeiss/Baader Binoviewer
4) Takahashi Sky Patrol II Mount
5) Collins I3 Piece
6) Dan Mounsey's Custom Cases
1) Starlight Nights (book)
(By Leslie Peltier, $19.95, reprinted by Sky Publishing)
Leslie Peltier grew up on a rural farm in Ohio at the turn of the century.
By the time his career was over, he had discovered a dozen comets and
had made over 132,000 variable star observations for the AAVSO. Peltier
grew up in a time where there was no running water and no electricity
in the house, and no automobiles on the roads. It was a time when the
newspaper only came twice a week, due to general lack of world news.
There is little I can say about this work other than it captures, perhaps
better than anything I have ever read, the joy, wonder, and peaceful romance
of looking up at the night sky. Time and time again, I am amazed and de-
lighted at Peltier's gentle, lilting way with words, and the way he describes
the most mundane events of his early life -- milking the cows, fetching a
glass of water from the bucket in the kitchen, waiting for the postman to
deliver a 2" refractor that he'd ordered. Peltier's writing takes you effort-
lessly back in time, and you feel as if you are there.
A true classic. I've seen first editions selling for as much as $200. That
this miraculous book had been allowed to fall out of publication for nearly
ten years amounts to high treason to our hobby. Get your copy before it
2) Box of Expensive Eyepieces from Markus Ludes/ APM
(Various eyepieces from Zeiss, Leitz, Kohki, Nikon, etc)
I didn't quite know what else to call this. During one of his trips to the
US, I had the opportunity to sit down with Markus Ludes over dinner and
talk to him about what he's been up to.
Think you've seen it all? Think again! From APM:
(L to R) Kohki, Zeiss (2), Leitz zoom, Zeiss erfle
Markus is a passionate, talkative, opinionated guy who talks a mile a minute
about any topic that interests him (mostly telescopes and optics.) Further-
more, once he takes a stance on a particular subject, you have no hope of
moving him one bit off of his position (don't ask him what he thinks about
American beer!) This led to an exhilarating evening as we bantered various
optical topics back and forth. After about four hours of this, I was mentally
exhausted and physically drained. However, I felt as if he could have carried
on all night.
After dinner, Markus gave me a box of unusual high-end eyepieces for me to
check out. Some of the highlights from the collection:
1) A group of Zeiss eyepieces, converted to 1.25" from microscope usage.
Some have the diopter adjustments still attached. These are superb; the
25 mm is perhaps the sharpest eyepiece I've ever seen in its class. The
field of view is somewhat narrow at 42 degrees. $95-$320 each, depending
2) A Leitz zoom (7.3 mm - 22 mm) eyepiece that appears to be much sharper
and sturider than the zooms you are probably used to. A very nice eyepiece.
3) A Kohki 30 mm 2" Widescan unit from Japan. Here's the latest entry in
the high-quality 30 mm sweepstakes. There's some contrast and sharpness
falloff near the edges of its huge 90 degree field of view. However, it's much
cheaper than the 30 mm Leitz or the 31 mm Nagler. $345.
4) A Zeiss 30 mm 2" 85 degree Erfle. Interesting eyepiece. Adapted from
institutional use, this one has the dipoter adjustment and mounting board
still attached. Again, there's some sharpness falloff near the edges. Impres-
sively solid and massive construction. Expensive. $530.
5) Some Nikon 1.25" eyepieces adapted from spotting scopes. While I liked
these, I liked the Zeiss units even better. Reasonably priced. $115-$188.
Check with APM if this sort of thing interests you. Of the samples I saw,
the 1.25" Zeiss units seemed to me to be the keepers of the bunch. They're
sharp, lightweight, and not too expensive. Also, keep in mind, you're order-
ing this stuff from Germany. Allow for extra lead time for delivery, and the
occasional currency fluctuation.
3) AP/Zeiss/Baader Binoviewer
(About $1200, may be NLA)
A properly functioning binoviewer rig is a lot like a finely-tuned CCD setup: it's
a thing of beauty when it works, but you don't see the expense, frustration, and
sweat-equity that it took to get the system up and working.
Binoviewing seems like the most natural thing in the world. You get to use
both eyes, which reduces strain. However, things aren't that simple. There
are a number of factors to consider.
The AP/Zeiss/Baader binoviewer, the best
you can buy (19 mm Panoptics shown)
1) First of all, you have to double up on your favorite eyepieces. As if the
cost of these binoviewers alone isn't enough! What's more, there have been
several revision levels to the Naglers and the Meade Series 4000 eyepieces,
and you need to get an identical pair.
2) As you go up in power, it becomes harder for the brain to merge the images.
So you may be stuck with using lower powers. Also, people's ability to marry
the two images varies greatly. I know of one experienced observer, for example,
who cannot merge the images in any binoviewer, under any conditions.
3) Binoviewers take up focus travel. A lot of it. Sometimes, five inches or
more. You'll be racking in your focuser all the way. In fact, on many tele-
scopes, you can't come to focus at all without using an interposing barlow
lens. This magnifies the image, of course, so if your scope has a long
focal length, you are strapped in to medium and high power...
...but it gets worse. Barlow lenses depend in part on the distance between
the lens and the eyepiece to do their thing. Since you're interposing a
binoviewer between the barlow and the eyepiece, the actual magnification
of a 2X barlow becomes something like 3.5X-5X. Thus, your "low power"
32 mm Plossl instantly becomes a 6 mm - 8 mm eyepiece.
Since it becomes harder to merge the images as the power increases, you
may not be able to use a binoviewer at all on your particular telescope.
It's like a giant house of cards that comes tumbling down if one part doesn't
4) If you own a large, truss-type Dobsonian, you're in luck. Call your
scope's manfacturer and order a second set of truss poles that are about
5 inches shorter than your original set. Technically your secondary will
now be undersized, but this is usually a small concession if you have at
least 15 inches.
5) This AP/Zeiss/Baader unit is the best binoviewer I've ever seen. It comes
with a dedicated diagonal (of superb quality) and does not take up all that
much focus travel. In fact, on AP, Takahashi, and TMB refractors, you do
not need a barlow at all. Just plug it in, and enjoy!
6) If you cannot find the AP/Zeiss/Baader unit, the TeleVue binoviewer is
almost as good. It's of excellent quality and comes with a dedicated "true"
2X barlow (ie, the 2X does not become 4X or 5X in use.) About $1000.
Note that TeleVue also made another version for several years that did
not have the integrated barlow lens. It's also recommended, but if you
get one, it's up to you to deal with the barlow issue.
7) The BW Optik unit (sold through Lumicon) is very good, and reasonably
priced at $749. Lumicon sells a dedicated barlow for an additional $85.
8) So far, I have not liked any of the 45 degree units I have tried. The angle
seems all wrong, the interpupillary distance adjustment is finicky and frus-
trating, and their prisms are usually undersized, vignetting the image at lower
powers. Also you can forget about these for use on Newtonians. If you are
considering buying a 45 degree style unit, I strongly urge a personal audition
to make sure the binoviewer satisfies you. If you don't have access to samples
to try, stay with the straight-through style like the AP/TeleVue/BW Optik (ie,
the style that "look" like real binoculars.)
9) If you're new at this, stay with low power at first, and move up slowly.
Recommending eyepieces is a dicey task, as everyone has different tastes,
scopes, and budgets. But here goes...
End Page 6
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