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The Tasco 7T-E

There it sat, in the back of the blue van, in it’s walnut colored wooden case.  The top was open, the optical tube was on the top, the wooden legs right beside it.  There were quite a few scratches on the legs, and I could see a couple of long ones on the white tube.  I felt myself edging toward hesitation.  Maybe I should just get back in the car and head for home.

The seller reached in and pulled the black metal dew cap out of the lens hood to show it to me and I could hear it coming before he said it.

“They don’t make them like this any more, you know.”

I looked at it.  More scratches, plus a dent near the middle.  The hesitation leaped several more notches up the what-am-I-doing-here scale.


It was a brisk Saturday morning in November.  I was standing at the back of a van, with both doors open, in a mall parking lot, debating whether to remove cash from my pocket and put it in the hand of a person I had never met.  In broad daylight.  Besides trying to wrestle with the rising hesitation, I was wondering if anyone was watching us — and hoping they wouldn’t get the wrong idea.

Now hang on a minute,” my telescopic conscience said.  “You can’t expect brand new.  This thing is old.  You gotta expect a few scratches.  You didn’t drive two hours to get here to surrender to a few well-earned scrapes . . . . . did you?”   I hate it when that thing starts talking.  It likes to spend money — mine, mainly.

“OK,” I said to the seller.  “What does the lens look like?”

He pulled it from the box, tilted the scope up towards the sky, and said, “Here, take a look.”

I did.  A bit of dust.  No scratches. No clamshells.  Silver-colored spacers between the lenses.  It looked much better than the tube.

“How are the views?”  I asked, instantly regretting the question.

“Oh, geez,” he said.  “They’re wonderful.  Stars are pinpoint sharp, Jupiter just leaps out at you.  Great double star scope.  Wonderful contrast.  Really, it does a very nice job.”

I looked at his son.  Fourteen years old, maybe.  Short, round, baseball hat on backwards.  Gym shorts down to his knees.  “What do you think about it?” I asked, not sure what to expect.

“Oh, man, it’s nice.  I love the moon in that scope.”

He grinned.  He looked at his dad.  They smiled at each other.  Non-verbal collusion, I thought.

I took the tube, held it up to the sky, and sighted along the edge of it.  “Look how long that thing is!  Feel the heft!  Imagine yourself sitting behind that long tube pointing up into the sky with Jupiter at the other end of it.  One thousand millimeters of focal length —– how could you go wrong?”  My telescopic conscience again, with a subtle nudge.

I looked at the seller’s son again.  He smiled again.

I hesitated.  I wavered.  I slipped.   I handed over the cash.


I had two hours on the return drive to wonder about the contents of that wooden box in the back of my car.  Even though it was firmly in my possession, I still had those parking lot doubts.  An old telescope  . . . . .  an old 60mm telescope  . . . . .  a slightly scratched old 60mm telescope  —–  and an old mount and old wooden legs, all of it in an old brown wooden box   . . . . . . . . .    well, it sure wasn’t an APO, that was for darn sure.

"You know, son . . . . . "

“You know, son . . . . . ”  (ekrd.wikispaces.com/Edwin+Hubble)

You can conjure up a lot of what-if’s on a two hour drive, but I finally left the doubts somewhere along the side of the road about halfway home . . . . . . . and began to think about sitting under the stars behind that long white tube on those long wooden legs, with Edwin Hubble standing next to me in a cloud of pipe smoke, saying, “You know, son, my first scope didn’t come close to this nice piece of work you’ve got here.  What do you say we look for a few Cepheids in Andromeda tonight?”

Obviously, a serious case of drifting from doubt to delusion.

Now of course the first thing I did when I got home was to take everything out of the box.  After I had it all put together, I began to feel much better.  That long white tube looked great on the tall wooden tripod, the mount seemed to be reasonably smooth, the slow motion controls engaged easily, the clutch locks did what they were designed to do — but the focuser was about as wobbly as a loose wheel held on by a single lug nut bouncing over a pothole filled road.  I tried tightening each of the two screws on the bottom of it, but it just made one side or the other bind a bit more.  I looked at the three screws holding the focus assembly to the tube — and in a leap of reckless faith — because I had no idea what I would find — I took ’em out.

OLYMPUS DIGITAL CAMERAAs I removed the last screw, the focuser started toward the floor.  I caught it, and as my hand grabbed it, I saw something shiny go past and land on the floor.  I leaned over, picked it up, and found myself looking at a red-something-or-other about 1 1/2″ long by 1/2″ wide.  The narrow length of it was slightly curved to fit the inside of the scope tube.  It looked almost like delrin — but it couldn’t be delrin — the scope was manufactured before delrin was invented.

I peered into the end of the tube with a flashlight and could see two more of the same pieces attached firmly to the inside of the tube.  It took a few minutes, but I finally realized they were spacers that were used to keep the focus tube parallel to the inside of the scope tube, and their surface was shiny to make it easier for the focus tube to slide back and forth.  I took some thin — very thin — scotch tape, applied it to the top edges of the piece that had come out, and after some trimming and a couple of false starts, I managed to slip it into position so that it was spaced evenly from each of the other two pieces, put the focuser back in place carefully, tightened the three screws, and gave the focus knob a turn — smooth as glass.  My first 60mm repair job and it was a success!

I still don’t know what exactly that red piece is made of, but it’s still sitting in the focuser three years later with that tape holding it in place, and the focuser still glides back and forth with the greatest of ease.


After a couple of non-cooperative nights of rain, I had a clear evening to see what this skinny white monster could do.  At that point, I didn’t have a .965″ to 1 1/4″ hybrid diagonal, so I used the .965” OLYMPUS DIGITAL CAMERAdiagonal and eyepieces that came with the scope.  I pointed the tripod and mount to the north, adjusted the latitude control, put Polaris in the center of a 20mm eyepiece, and took a long, hard look.  The primary gleamed back at me like a yellow-white jewel on black velvet.  I replaced the 20mm with a 12.5mm eyepiece and was able to pick out its faint companion.  I racked the focuser in and out — evenly spaced concentric rings on both sides of focus.  Certainly no problem with the collimation.  Pretty darn good so far.

Now, for the object that my telescopic conscience had been dangling in front of me — Jupiter!

I turned the scope toward the south, lined up on that Jovian point of light just to the west of the meridian, and centered it in the 20mm eyepiece.  Nice, bright, sharp — and small.  Hmmm — out with the 20, in with the 12.5mm.  I refocused, took another look, backed away for a second, looked again, backed away once more, then looked again, started to mutter something, and nothing came out —— words failed me!

OLYMPUS DIGITAL CAMERAThe image was still small, but it was sharp, crisp, clear, and bright.  The three visible moons were beautiful pinpoints of light, and both belts looked like they were etched across the face of the globe  — it was simply amazing.  From the start, when I first saw the pictures of this scope, I really had no idea what to expect — but I never expected anything like this.  I just could not believe it.  I sat still for about fifteen minutes totally absorbed by that image, and then I noticed a very small, white pinpoint of light right at Jupiter’s west edge.  It was Io, which I hadn’t seen moving across the front of Jupiter.  I watched as that very small white dot of light slowly popped free from the edge and into silhouette against the blackness of inter-planetary space.

Awe struck I was.


Since that time, I’ve used the Tasco mainly for double stars, although it frequently finds its way back to Jupiter, as well as to Saturn.  It splits Epsilon Lyrae with no effort at all.  The reddish-orange primary and slightly green secondary of Raselgethi is a thing of startling beauty; I’m riveted to the eyepiece when I gaze at the orangeness of Algieba; and at about 75x, Meissa rewards me with a small dot of light nestled tightly against it’s larger blue-white companion.  Splitting Rigel with it is usually a breeze, but the first night I did it, I’m sure most of my neighbors for several blocks around could hear me.  Like my first view of Jupiter, I couldn’t quite believe it.

And when the seeing is poor and the transparency great, deep sky objects are always an attractive target.  I quickly nailed M1, the Crab Nebula, even though I was told by several people it couldn’t be seen in a 60mm scope.  M31 is a wonderful sight, but a galaxy that really caught me by surprise was M33, the Pinwheel in Triangulum.  On a night when the transparency was five on a scale of five (five being excellent), it stood out very clearly against the black sky background.  I could actually detect a bit of structure in it, was able to trace its irregular shape, managed to pick out a few stars near its center, and caught a glimpse of the condensed area known as NGC 604 on the northeast edge of it.  M42 is worth a long look, and even though the field is narrow because of the 1000mm focal length of this scope, with a 30mm Tak LE, the nebulosity of the Pleiades is stunning.

And every time I find myself grinning from ear to ear when I’m at the eyepiece of the old Tasco, I hear the voice of my telescopic conscience again: “Told you so.”



My 80mm Mizar Shows Me a New Way to Look at Xi (ξ) Boötis

Click on this or any of the other photos for larger views.

Several years ago I was skimming along through Cloudy Nights’ Classic Refractor Forum and I came across a discussion about an old 80mm Mizar refractor someone had purchased that turned out to have a badly chipped lens.  I followed the discussion for a few nights and read with more than a little interest of the owner solving the problem by replacing the old lens with a Carton 80mm f/15 lens.  I forgot about it after a few days, but then one evening I found myself looking at an ad for that very same telescope, with a mouth-watering photograph of it sitting on top a very tall and solid-looking wooden tripod.  Resistance never entered my mind.  My fingers flew across the computer keyboard in response to the ad, and about a week later it arrived at my door.

The long monster showed up well packed in a solid and very heavy wooden box that I opened with devilish delight.   I worked  methodically at removing all the paraphernalia from its slightly musty temporary home, laid each part out carefully, and then whistled and hummed as I pieced it together.  Everything was there, it all worked, the tripod was every bit as stable as it looked in the photo, but the old Mizar EQ head was a rather disappointing piece of –- well -– let’s call it hardware, although even that is more complimentary than it deserved.  I passed that part on to someone at a bargain price, and proceeded to place an old Polaris mount on top of those long brown wooden tripod legs, which couldn’t have been happier.

There was one other problem I had to wrestle with –- I spied it when I bought the scope –- and that was the absence of a dew shield.

Now I live on the north Oregon coast, a part of the world that is both famous and infamous for the amount of rain it gets.  Most years see ninety to one hundred inches of rain, at least sixty percent of which falls from the sky between November and February.  But even when the rain isn’t raining, the moisture content in the air at night makes the use of a dew shield and a dew heater mandatory -– without those two items, the lens of a telescope won’t survive ten minutes before succumbing to the moisture laden atmosphere.

So I had to come up with a dew shield.  That unshielded lens looked great at the end of the scope’s cream-colored tube, but telescopic life would be impossible without it.

One day I happened to be at the local hardware/lumber store and I heard a bell ring in my head as I walked past a piece of PVC tubing.   I ran back home, measured the outer diameter of the exposed lens cell, went back to the store, and found the PVC tubing was the wrong size.  I was about to give up on the idea when I stumbled across a piece of long black plastic irrigation pipe, the same stuff used for mundane things such as sewer lines.  I yanked my tape measure out of my pocket, stretched it across the opening of the pipe ——- and it was within 1/8” of what I needed.

I had ‘em cut a piece down to size, and that’s what decorates the end of that cream-colored Mizar tube.  For some reason that pipe has a real tendency to sweat, both inside and outside, so I added some flocking to the inside of the tube, which cured the inner part of the problem.  I also replaced the focuser with a Crawford Machine Crayford single-speed model, found an old Royal Optics olive green finder that was without a home, attached it to the right side of the tube –- and made the whole thing into a demon of a double star scope.

Now due to a more infamous than normal stretch of that infamous Oregon coastal weather, this poor scope hadn’t seen starlight since last November — which was about six months into the historic rainy past.  Every time I walked past it, I could feel a restless energy radiating from it –- as in “Get me under the stars!  I’m tired of being cooped up in this house!”

So I grabbed it off its storage rack a few nights ago, put it back on top of the old Polaris mount, and marched the whole thing outside.  For some reason the altitude adjustment on the mount had slipped –- it had probably sagged in disappointed expectation of ever seeing starlight again –- so I spent some time re-adjusting and lining everything up.   And when I got done, I had an absolutely delicious, mouth-watering view of Polaris.  I believe I had a 15mm TV Plössl (80x) in the scope, and it displayed the diminutive secondary with something resembling an etched crystal clear clarity.   And the Polarian primary beamed back at me from the center of a yellow-gold diffraction ring which floated and fluctuated in a slow dance around it.  Ah, yes -– another one of  those  moments!   I lingered –- what else could I do?

An 86% full waning moon was beaming lurid rays of yellow-white light onto my right shoulder and into the corner of my right eye, so I decided to swing the scope over to the star it was named for, Mizar, and let the moon bounce its beams off the back of my head.   And again, the view was stunning.  I replaced the 15mm TV Plössl with a 24mm Brandon (50x), which had the effect of pulling Mizar’s two companions closer together.  Beautiful, beautiful, beautiful  ……………… beautiful.  Alcor sat to one side — I could swear it was admiring the view, too –- and right in the middle was Greg’s side car, also known as Sidus Ludoviciana, or Ludwig’s Star.

Then I slid sideways to Alkaid at the end of the Dipper’s handle and aimed a few degrees above it to the northeast to catch a pair of Boötean beauties, Kappa (κ) and Iota (ι) Boötis.   Both pairs of doubles decorated the field at the same time in the Brandon, but I had to look carefully to pick out Iota’s 7.4 magnitude companion (the fainter of the two secondaries), since the moon was doing its best now to turn the sky to daylight.  It was getting more than a little help from a damp haze in the air which was hard at work employing every available molecule of moisture to magnify the moon’s reflected photons.

Next I panned over to Izar and spent thirty minutes or so prying the secondary off of the primary, which I finally managed reasonably well with the 15mm Plössl, and then I looked up and saw a weak glimmer of light coming from about where Xi (ξ) Boötis was supposedly shining.   So I pointed the Mizar’s long white tube in that direction, peered into one of the finders, centered it, and then pulled up my chair and sat down for a long look.

Xi (ξ) Boötis  (Σ1888)                HIP: 72659    SAO: 101250
RA: 14h 51.4m    Dec: +19° 06′
*****  Magnitudes      Separation       PA           Latest Data
AB:      4.8,   7.0                  5.9″            306°        WDS 2012
AC:      4.8, 12.6                71.6″           340°        WDS 2008
AD:      4.8,   9.6              161.1″           286°        WDS 2008
AE:      4.8,   8.7              268.6″           100°        WDS 2009
AF:      4.8,   9.2              333.8″              41°        WDS 2009
Distance: 22.1 Light Years
Spectral Classification:  G8 (A), K5 (B)

The “D” companion can be see just to the west of the AB pair, and the two northernmost of the north-south aligned trio on the opposite side are the “F” and “E” components.  “C” was hiding behind a veil of bright moonlight.  (East & west reversed, click for a larger view).

I was still using the 24mm Brandon, and in its minimal 50x, “B” was barely separated from “A” –- which made the view all that more attractive.  The seeing was slipping slowly from a III to a II, so occasionally the secondary would get yanked back into the primary, and then it would suddenly pop loose again, where it would stay for several seconds.  My eyes roamed across the entire field, caught especially by the trio of stars in a north-south alignment just to the east of the dancing primary/secondary pair –- but they kept coming back to that dance, again and again.

After several minutes of that, I became more aware of the motion in the eyepiece.  There’s no drive on the mount, so the entire field was drifting to the west, which was to the left side of the field of view as I was situated  ——  and it impressed me as a waltz in slow motion.   And then my mind suddenly re-configured the stars in the field into the shape of a goose or a swan.  The primary/secondary pairing was the head, the three stars to their east in the north-south alignment were the wings, and further east  at a distance of about twenty-five arc minutes, were a detached pair of stars that served as the tail.

It was fascinating to sit there and watch that slow motion flight take place.   The entire field of view in that eyepiece amounts to something like a full degree –- that, coupled with the low 50x magnification, was more than enough to result in a very slow trip from the east edge of the field to the west.  I didn’t time it, but I would guess it took close to a minute for the entire configuration to wing its way across the field.

It was another one of  those  moments.

It’s uncanny how they unexpectedly dawn on you.   Suddenly  the view in the eyepiece –- regardless of whether it’s boringly normal or particularly captivating –- takes on a new dimension.   Something that was there all along, but beyond the boundary of conscious awareness, quickly blossoms into view –- and nothing about that field of view strikes you as “boring” or “normal” again.

And that’s what happened.

And when that happens, I’ve learned you don’t leave it quickly.  Your role in the continuing drama of the unfolding of the universe is to sit there at that particular moment in time and soak it all up.   And I did.   For something like thirty minutes.  I didn’t budge, I didn’t move, I barely breathed.   Just me, a 24mm Brandon, an old Polaris mount, a slow motion control, and that long, creamy white Mizar telescopic tube, pointing through the moonlight at a narrow swath of interstellar space twenty-two light years away.

P U R E   bliss!

Seeing double the natural way – looking up with both eyes and binoculars

The best way to look at the stars is to lie back in the grass on a hill side on a warm summer’s night in a region free of light pollution and look up. The only way to improve on this is to add binoculars. And when it comes to splitting doubles, this is doubly true!

Bring on the doubles! - 25X100 Zhummel binoculars.

Binoculars make a terrific double star instrument because you are doing what comes naturally – you are using both eyes and you are looking up. And there are loads of beautiful doubles that provide absolutely charming splits when viewed properly in binoculars. What’s more, binoculars give you a sense of context. Because they give a correct image and wide field of view, the transition from naked eye is not so abrupt or confusing. It’s a great way to learn your way about the night sky and to keep what you view in context.

I should add that once you get past the smaller binoculars it is neither simple, nor cheap –  it actually gets about as complicated, cumbersome, and expensive as using a telescope. Image stabilized binoculars maintain the size and portability we have come to associate with binoculars while making it easy to get a steady view, but they are expensive. However, most of the time I use larger binoculars and their mounts are  as heavy and awkward as any mount and as expensive. There’s no free lunch here – but for me the binocular astronomy experience is well worth the effort and price.

But I have a confession to make. Until very recently I didn’t consider this the case. I thought binoculars did a poor job with doubles – but I now think this was my special hurdle to leap and now that I’m over it I’m in bin ocular double star nirvana – so I decided to provide some basic guide lines for splitting doubles with binoculars, plus a short list of some especially useful binoculars doubles that range from easy to difficult and will give you a way to test yourself and your binoculars, should you care to.

My knowledge comes the hard way – I acquired it through numerous hours of observing and most of them were relatively futile. If you want to read the whole saga of my personal journey with binocular doubles, go here.  But I really think most people have a far, far easier time of it with these inexpensive and highly portable instruments. So let’s get started.

Short List of Binocular Doubles

First, here’s a list of some excellent spring and summer binocular doubles arranged in order of the easiest to the most difficult. The top of the list can be split by any binocular, the mid section takes a good astronomy binocular, such as a 10X50, and the last few call for big astronomy binoculars in the 20X80 or 25X100 range – which can now be acquired quite cheaply, incidentally, but mounting them is the rub.

  • Mizar and AlcorMany can split these two famous stars in the handle of the big Dipper with the naked eye, but for me it always takes binoculars – any binocular.  RA:  13h 24m   Dec:  +54° 56′ – Mag:   2.2, 4  – Sep:  11.8′ (708.5″)  – PA :   71°
  • Epsilon Lyra – Double Double – No, I don’t mean to actually split each star – I mean the initial split into Epsilon 1 and Epsilon 2 – that’s easy for any binocular and since these are in the same low-power binocular field as Vega, easy to find. I am able to split these with my  6.5X21 Pentax “Papilio” – the “butterfly” binoculars.  RA: 18h 44m   Dec: +39° 40′  Mag.: 5, 5.2 –  Sep. : 210″
  • Nu Draconis – The famous “Dragon’s eyes” are delightful because the split is clean with just about any binocular and the stars nearly identical. RA: 17h 32m Dec: +55°11′  Mag: 4.88, 4.86 Sep: 63.4″ PA: 311°
  • 16 & 17 Draconis – This pair is more widely separated and easier to split than Nu, but I listed it after Nu because it is a bit more difficult to find. RA: 16h 36m Dec: +52°55′  Mag: 5.4, 5.4 Sep: 90″ PA: 196°
  • Albireo – Beta Cygni – I think this has got to be one of the most popular double stars there is, and while it mark’s the Swan’s head, it is easier to find with the naked eye, than with binoculars. The reason is it’s in the heart of the Milky Way and it’s hard to know which is the star you seek because there are so many. RA: 19h 31m Dec: +27°58′ Mag: 3.4, 4.7  Sep: 34.7″ PA: 55°
  • Psi Draconis – I know I have the right star when I see the perfect little kite asterism  in my binoculars with Psi as the brightest member – RA: 17h 41.9m   Dec: +72° 09′  Mag.:   4.6, 5.6  Sep:   30.0″  PA:   16°
  • RegulusAlpha Leonis –  With a separation of nearly three minutes of arc you would think this one would be up with the other easy stars – it’s isn’t because the magnitude difference is so great – great enough for me to call ont he light grasp of an 80mm or 100 mm binocular. RA: 10:08:22.1 / Dec: +11:58:01 – Mag.: 1.35, 8.12  Sep.: 177.6  PA: 207°
  • Mizar – Yep, this is the brighter half of Mizar and Alcor and it does make a lovely split, but it takes more binocular muscle – more like 20X and easier with 25X.  RA:  13h 24m   Dec:  +54° 56′   –  Magnitudes   2.2, 3.9 – Separation  14.3″ – Position Angle    153°

Short check list of guidelines for getting the most from your binoculars

Garrett Optical 28X100 binoculars on Universal Astronomics Millenium Mount with rotating beach chair - to me the perfect chair to sit in while using binoculars since it both leans back and rotates, but hard to find and the most recent version of this chair I found was not that well made.

From my experience I’ve developed some basic guidelines for splitting doubles with binoculars.   Many of them you probably already do. If so, treat this as a reminder.

  1. Wear your glasses if you have astigmatism – otherwise do without.  And if you need glasses, seek binoculars with long eye relief and flexible eye cups that roll back.  You only need to see the center of the field to split a double, but the whole field is useful for finding the double.
  2. Sit down – or better, lie back in a lawn chair – you must be comfortable. Get in a position where you are looking at your target area without strain, then bring the binoculars to your eyes. This is important. Even with a nice Parallelogram mount I frequently see people raising their head and straining their necks to look through binoculars. Take the time to make the mount do the work for you.
  3. Hold the binoculars steady – even 7X50s will benefit from being on a tripod, or parallelogram mount unless, of course, they are the image stabilized types. Most people think they can hold binoculars steady. Wrong! And this is doubly wrong if you’re trying to split close doubles. An ordinary photo tripod can hold small and medium binoculars, but will likely result in a pain in the neck. I can’t use one for anything except objects that are so low the atmosphere becomes a problem. However, I know excellent observers who use such amount for all their  binocular observing. I much prefer the kind of parallelogram mount that puts the binoculars to one side of the tripod or pier so you can observe comfortably while seated in a lounge chair. This isn’t laziness – it’s practical considerations related to seeing well.
  4. Focus carefully – very carefully – with center focus types remember to focus first the left eye with the right closed, then do the diopter adjustment for the right eye while keeping the left eye closed. I know everyone should know this already, but it’s surprising how many people have used binoculars casually for years without being aware of it.  Acceptable focus for land views just isn’t the same as the critical focus needed to split close doubles. Once you have the diopter set, you can leave it alone and just use center focus.
  5. Get the interpupilary distance right!  That is, make sure the binoculars are the same distance apart as your eye. This is another one of those things that might evoke a duh! But the truth is, your brain wants to see a single image and might be working overtime to give you one because the binoculars aren’t adjusted properly for your eye. (This is also true if your binoculars are out of collimation – but evaluating and correcting collimation is a topic beyond the scope of this post.)
  6. Spend time on target – Look for at least one solid minute – don’t expect instant success. Don’t fiddle with the focus forever – give your eyes time to adjust. This is one of the key instructions in Crossan and Tiron’s “Binocular Astronomy.” They write:”the most important thing in observing is to really look – a mere glance at an object or a field is simply not enough. You must keep your eyes at the oculars for a full minute at a time.” I can’t stress this enough. over and over again I see people taking mere glances and thinking they have seen all that can be seen. As Holmes told Watson: “You see, but you do not observe.”
  7. Relax your eyes – let them focus at a distance and get used to it. I wish I could explain this better. I feel it’s important, but I’m not sure exactly how to describe it. If I’m in doubt I take down the binoculars and just try to let my eyes focus on the stars. Then I come back to the binocular view.
  8. And if all this fails to deliver sharp star images, maybe you have a problem similar to mine – back off from the eyepieces an inch or two, move your head about some – find the correct head position – the one that works and yields sharp stars.

This last has driven me crazy and continues to puzzle because believe me.  Points one through seven didn’t make a difference for me until I could settle the issue of point 8 and right now I’m not sure how many others have a similar problem, but I think it’s relatively few.

I’ve been to both the eye doctor and my massage therapist and right now the one whose advice makes the most sense relative to this situation is my massage therapist. She noticed me holding my head a bit funny and she knew I had flexibility problems with my shoulder and neck. These apparently don’t come into play when I am leaning over the eyepiece in the diagonal of  a refractor or catadioptic telescope – or for that matter, looking directly into the eyepiece of a reflector. But when I look up to look through binoculars, all bets are off. What feels natural to me simply isn’t the position that yields sharp star images. For years I have blamed this on the quality of the binoculars. Then for a while I blamed it on what I perceived as my astigmatism. But tests show that astigmatism is slight and what I am finding is critical is getting my head into a position that works – even if it feels unnatural to do so.

I discovered this by backing away from the eyepieces as much as two or three inches and moving my head around, tilting it in various angles.

My advice to you? Don’t worry about this unless you’ve tried everything else and are still having problems getting sharp star images.

Meanwhile, check out some of the doubles on the short list. Warm up by trying the easiest first – and get your focus right on them. Most are conveniently grouped with other bright stars and easy to track down – and each is distinctive. Even if you have seen them all in telescopes, the binocular view is different and special. Give it a try and see if you don’t agree.

More binocular astronomy resources:

Binocular  Highlights” by Gary Seronik – this is a great book to begin with. It mentions several double stars, but a lot of other good objects to look for with your binoculars. Also, scroll down his web site for some excellent binocular reviews and related suggestions on mounts.

Review of Binocular Mounts – Go here to learn of  some of the possibilities of commercial binocular mounts. If you’re handy with tools, there are plans here for making a parallelogram mount.

Binocular Astronomy, Crossen and TironAgain, a good guide. I have the first edition – have not seen the newer one advertised here, but I assume it is at least as good.  This is a general guide with lots of solid observing advice and several specific doubles.

Binocular Double Star  Club – Here’s a good list to whet your appetite – and if you’re into “awards,” go for it.

And now for something totally different — a Refractor Review!

A few months ago, a remarkable 100mm refractor found its way to my front door and landed in my hands.  Now it’s no secret that long focal length refractors attract me like a moth to a front porch light, but in this case there were a few other factors involved — such as a long black tube, a gleaming brass dew shield and finder, and above all else, the aura of 19th-century England which surrounds it in the same way an elliptical galaxy is encircled by a glowing nebulous cloud of stars.  For those not familiar with the age, the late nineteenth and early twentieth century was an era when high quality achromatic refractors, crafted by Thomas Cooke & Sons in England and Alvan Clark & Sons in the United States, ruled in many observatories in both countries and in continental Europe.

So to get to the point, I was asked by the person who hand-crafted that refractor, Richard Day of Skylight Telescopes, if I would be interested in doing a review for Astronomy Technology Today — and the rest is now history.  The review has been published in the current issue (March-April, 2012) of that magazine, along with an account by Richard of how he became involved in the art of building hand-crafted refractors.

With the blessings of Gary Parkerson, the editor of the magazine, I’m posting my original draft of that review here.  If you have a subscription to the magazine, you can download a .pdf version of either the entire current issue, just my review, or even Richard’s piece, by going to the ATT website.    But — you need to be a subscriber to have electronic access to the magazine — and,  if you’re not, you can subscribe to the digital edition for the current  reduced rate of ten dollars.  I’ve been a subscriber almost since the magazine first came out in 2007, which should say all there is to say about my high opinion of it.

So ………. without further ado, and a little inspirational help from the gracious and very dependable Admiral William Henry Smith …………..  here we go!


The Skylight 100mm f/13 Refractor: A Different Experience

Rats! Rain and more rain! Enough to drive a starlight addict into a photon deprived fit!

I sat back in my chair, opened my well worn star atlas, and began to plot new paths through the double star studded heavens as the rain beat against the windows and the wind rattled the doors and roared through the trees — again.  Let’s see now, this is day nineteen — twenty-one more to go and we’ll reach forty.  Maybe I better get back to work on that ark I started last year.

I worked my way across the middle of Gemini, and then down into northern Orion, circling and plotting as I went, making lists of magnitudes, separations, and position angles, and then laid my notes aside, closed my eyes, and began dreaming of clear dark skies filled with jewel-like points of starlight ……………

Click on this or any of the other photos for larger views!

……………  And then I heard the sharp scrape of a chair being dragged across my observing deck, just outside the window. I jumped up, walked over to the door, opened it carefully, and peered into the moonlit darkness — and over in the corner where I normally set up my telescope, I saw a figure in an old black frock coat, wearing a tri-cornered hat and holding a long-stemmed pipe, peering intently into a highly polished black tube with a gleaming brass finder just a few inches from his hat-covered head.

Hmmmmm, I hummed — that guy looks vaguely familiar, even a bit like the much admired Admiral William Henry Smith of mid-nineteenth century British astronomical fame.

I grabbed a coat, walked outside, and quietly started toward him. As I got closer, he looked up from the eyepiece, with blue-white starlight sparkling in both eyes, and in a heavy nineteenth century London accent with an aroma of sea salt hovering about it, said, “Something I can do for you, m’good man?”

“Yes, you can,” I began hesitantly.  “You can start by telling me who you are, and how you got here.”

He stood up, took off his hat, and with a low bow and a flourish of his coat, said, “Allow me to introduce m’self, m’dear sir.  I am the good Admiral Wm. H. Smyth, well known author of that best selling 1844 compendium of the stars, A Cycle of Celestial Objects, of which you twentieth-first century folks typically peruse only the fragment known as The Bedford Catalog!”

. . . the brilliant white light of the moon was busy beaming its bright rays off of a beautiful brass dew shield.

“I thought that might be the case,” I replied a bit distractedly, still wondering how he got here. It was that telescope — I couldn’t take my eyes off of it. The long, gleaming black tube literally shimmered under the brilliant white light of the moon, which was busy beaming its bright rays off of a beautiful brass dew shield.

“Mind if I take a peek into that thing?” I inquired.

“Certainly not, m’boy! Please, peer into this heavenly one hundred millimeter instrument!”

I positioned my eye carefully in front of the eyepiece, reached for the focus knob …………………

…………….. and suddenly a strong gust of wind rattled the entire house and sent a refractor length tree limb crashing into the deck. I shook myself out of my stupor, looked around in a slight daze, got up, walked over to the door, opened it, and looked outside —- nothing there but a large limb over in the corner of the deck where I normally set up my telescope.

Very strange. I ought to know by now not to eat oysters and sardines this late at night.

That long black tube, with the gleaming brass dew shield, and the brass finder ............. there it was!

A few nights later — it was still raining, and the wind was still blowing, and I was scrupulously avoiding the sardines — I was inspecting the internet for possible purchases of an astronomical nature, and suddenly I felt my breath catch.  That long black tube, with the gleaming brass dew shield, and the brass finder ………….  there it was!  The telescope in my dream!

I didn’t hesitate for a tenth of an arc second.  I placed the order, and three days later it arrived in a large brown truck and was carried up to the front porch while I stood in stunned silence.  Under clear skies, even.

Now, the truth is, when I placed that order, I was a bit more than a bit concerned about a telescope of that length surviving the journey from London to southern California to Oregon. So I opened the stout outer box very cautiously, then a similarly stout inner box, and removed enough molded foam and bubble wrap to float that ark I never finished all the way to Hawaii.  Very impressive work.

Finally, after what seemed like a short version of eternity, I lifted a long bubble-wrapped tube out of the box.  And then I saw it — a red sheen on the other side of the bubbles! A red scope? I thought this thing was supposed to be black!

Slowly, carefully, cautiously, and with my cup overflowing with concern and curiosity, I unwound the crackling bubble wrap — and there, beneath all of it, was a bright red blanket wrapped carefully around the entire length of that long tube! Nice touch!

I unwound it, too, and carefully as well, and as I did, the long black gleaming tube and shining brass dew shield of my dream emerged into the admiring low afternoon daylight of northwest Oregon.

Inside the box I found a Baader Steeltrack focuser and that glowing brass finder I had spied in the moonlight when the Admiral was visiting. It didn’t take long to attach either of those, followed by a pair of Parallax rings I ordered separately, then my dovetail plate, and then  ……….. with visions of frock coats, tri-cornered hats, wool vests, and the remembered aroma of pungent tobacco wafting my way from the Admiral’s long-stemmed pipe, I hoisted the whole thing on to its mount, edged the dovetail carefully into the saddle, tightened the knobs, and proceeded to stand back in admiration  …………. and stared  ………..  and walked around to the other side  …………  and stared  …………  and walked to the front  …………  and stared  ………..  and then to the back  ………..  and, well,  ………….  I stared.  A lot.  While walking in circles.

The photos I had looked at on the internet were good, but not as good as this. The admirable Admiral was right — this was heaven.


So how does it perform?

Imagine the delicate strains of the Second Movement of Chopin’s Second Piano Concerto drifting across an open field on a late summer afternoon in early September, while the slanting rays of a low sun stream through the dappled rustling leaves of a tall stand of poplars.  Sublime it is.

Being that the skies were clear and cooperative that night, I lined up the mount and that long black tube on Polaris, and initiated my one hundred millimeter Skylight f/13 into the world of multiple star light.  With an 18mm Radian (72x) perched proudly in the diagonal, I gingerly dialed in that first light focus — and there was that beady little gleam of ninth magnitude secondarial light, looking me right in the eye from a jet black sky.  I could hear the Admiral’s voice again:  “Please, peer into this heavenly one hundred millimeter instrument!”

The waxing moon was out that night, shining at about 70% of full power.  Ignoring it for the moment, I swiveled the long black tube through that shimmering moonlight to the Orion Nebula just to take a peek.  I bent down to the finder, watched the three gleaming pools of light that decorate Orion’s sword come into view, put the center pool under the crosshairs, and then sat down and leaned over to peer into the 18mm Radian.  Despite the moonlight, the nebula stood out almost as if it was three dimensional.  The contrast was simply amazing — shades of light and dark gray ran randomly through the center and out to the edges — and there was just a very slight hint of color, dark red, dark pink even, very subtle, and beautiful beyond description.  And the four stars of the Trapezium looked like they were etched into crystal.  Wow.

There are two double stars in the vicinity of M42 that I’ve been eyeing periodically over the last few years, which can be a challenge for a four inch scope.  One is Σ 750, located at the north edge of that northern pool of light (NGC 1981).  The magnitudes of that one are 6.4 and 8.4, with a short 4.2″ of distance between them.  The other one, Σ 754, is at the southeast edge of the southern pool of light (NGC 1980), and it has magnitudes of 5.7 and 9.3 separated by 5.3 seconds of arc.  Both can be a bit difficult because the secondaries are mere phantoms of light that tend to suffocate under the glow of their primarial parents.

At 72x, each of those elusive secondaries was as distinctly separate and pinpoint sharp as could be.  There were no intermittent bursts of ravenous photons leaping from the primaries with intentions of swallowing the secondaries — just round, sharply defined primarial orbs with very delicate micro dots of white light perched impossibly close by, shining sharply on their own.  I sat and stared at each of them for about fifteen minutes.  Then I went back and forth between them several times — I simply couldn’t believe I was seeing what I was seeing at that relatively low magnification with no strain to my visual apparatus.  I’ve seen them like that in a five inch refractor at similar magnification, but not in a four inch.  Pure gold.  Pure undiluted, unaltered, unbelievable gold.

When I recovered, I scanned the sky in search of old favorites, and never met with anything anywhere near disappointment.  Sitting at the rear of that immaculate gleaming black tube with the moonbeams bouncing from the brass dew shield, I was ready to sell every scope I own and live happily ever after with just this one.  I can’t ever remember a reaction like this to a telescope.

Now I’m not going to rattle off esoteric mathematical formulas and phrases here.  I know optical gold when I look through it.  I checked the collimation that first light evening, first with a Cheshire tube — it was dead center — and then toward the end of the night on several first magnitude stars.  I looked closely at the in- and out-focus images of each of them and detected what might be a very slight over-correction, but if so, I wouldn’t touch this lens for all the Naglers in a Televue warehouse.

What about that dreaded two letter designation for color, CA?  Not much, I can tell you.  Jupiter shows a slight bit around the outer perimeter when out of focus, none when in focus.  That bright, 70% illuminated lunar orb flashed a bit of yellow around the edge, but just barely — I had to look for it to catch it.  The detail along the terminator was sharp, the shadows were jet black, and the rough edges of craters had that granulated texture which is characteristic of sharp optics.  There were flashes of color when Regulus was out of focus, but almost none when it was focused precisely.

Plastic plug? Nein! How about brass instead?

The only aspect of this beautiful refractor I can point to with any concern is the coarse focus adjustment on the Baader Steeltrack focuser.  It’s much too stiff when attempting to coax it into motion from a standing start.  That can be adjusted out, although it would be a huge help if Baader would get a data sheet on their web site with adjustment information.  But the fine focus knob is as smooth as a sharp knife passing through a succulent oyster, and contributed immensely to my success with the two double stars described above.  And it’s a very heavy duty piece of equipment that should easily hold a large two inch diagonal and a monster eyepiece, such as the 31mm Nagler or the 21mm Ethos.  I had a very heavy two inch Takahashi diagonal plugged into the focuser, and at one point I loaded it with a 5mm Radian, pointed it at the zenith, and it held firmly in place.  No horizontal sag, no vertical slip.

Oh, and one more thing about that focuser.  You know the little white plastic plug that fits into the end of the 1 1/4″ adapter?  Not on your life.  How about a heavy brass plug.  Neat.

As I’m writing this, the infernal rain has returned, and the starlight I’m addicted to is hiding on the other side of the scudding gray clouds streaming past overhead.  So I think I’ll amble over to my comfortable old chair, plot a few more courses through the heavens, and then lean back, close my eyes, and see if I can get in touch with the good Admiral once more.  I need to find out where I can get a black frock coat, a tri-cornered hat, a wool vest, and a long-stemmed pipe.  I’ve got an old stash of Whitehall tobacco I’ve been saving for a long, long time, waiting for the right moment — and I do believe I’ve finally found it.

Clear Skies!

Touring the 50mm/60mm Skies: Introduction

So what can you REALLY  see when you point a fifty or sixty millimeter scope skyward?


Which is to say a whole heck of a lot more than you may have been led to believe by the nay-sayers and those addicted to aperture, the ones who will lead you down the road to financial purgatory faster than a speeding photon disappearing into a black hole.  Not that I’m not fond of a bit of aperture.  Many a night finds me parked behind the long white tube of a five inch or six inch refractor, or occasionally an eight inch SCT.

But  —-  the purpose of these tours is to demonstrate that the heavens hold an abundance of stellar wealth which is visible in small apertures.  Many are the lonely objects just waiting for a sixty millimeter lens to pay them a visit.   So think of this as your chance to provide some visual comfort to a distant collection of forlorn photons.

Greg is covering similar territory with his DSC-60 posts, which can be found by clicking on the green “DSC-60” tab at the upper right of the home page, as well as by scrolling down to “DSC-60 Project” at the bottom of the “Select Category” window on the left side of the home page.  I’ll provide a link to those posts as we go if I’m covering the same territory.  The primary difference is these 50mm/60mm tours will focus on a small area of the sky — usually a single constellation — and provide four or five stars that you can observe easily over the span of thirty minutes to an hour.  I’ll go back over some stellar territory that either Greg or I have covered previously at larger apertures, and I have a few locations in mind already that have yet to be scrutinized by either of our pairs of probing eyes from the eyepiece side of a telescope objective.

So think of this as a spur to practice grab ‘n go astronomy with these small-apertured scopes, which are ideal for quick observing sessions.  Between the DSC-60 series and this series of tours, we hope to get one message across loud and clear — there are countless stunning sights to be seen in apertures of fifty and sixty millimeters!

The Equipment

I’ve been thinking about a series of this sort for some time, and finally was prompted to get going with it when a new double-sided mount arrived on my doorstep from the albion shores of distant England.  The mount is called the Sky-T, made by Synta, which currently is not available in the U.S.  So by the time it reached my Oregon address, it had a few miles on it, but was otherwise unscathed.  It took a few adjustments to get it working properly, but once I got that squared away, I found I had the ideal platform for mounting a 50mm scope and a 60mm scope side by side.

Up high on the left is the 60mm f/13.3 and clingingly tighty to its saddle on the right is the Zeiss 50mm f/10.8. In the supporting role is the Sky-T alt-az mount with very smooth slow motion controls. Click on the photo to get a closer look.

Which leads us to the scopes.

There doesn’t seem to be a lot available in the way of 50mm refractors, apart from finder scopes.  Swift made an excellent 50mm scope many years ago, which rarely comes up for sale on the used market, and I believe Tasco sold a 50mm at some time in the distant past, which is also seldom seen among the ads for used refractors.   And Stellarvue has offered their 50mm finder as a stand-alone refractor, dubbed the Lil Rascal.  It’s short focal length makes it better suited for use as a finder, as opposed to a double-star splitter, but since you can swap eyepieces in it at will, it merits consideration.   I was fortunate enough to come across a 50mm f/10.8 Zeiss on Amart, so I grabbed it quickly, and have been very pleased with it.  The views are crisp, bright, and mouth-wateringly sharp.

The 60mm scope we’ll use for these tours is one I put together from various parts.  The lens is an 800mm focal length Carton in a silver aluminum cell, which I mounted in a white aluminum tube.  That cool black lens hood is a yogurt container with the bottom cut out of it that fits around the aluminum cell like your frosty hand in a warm glove.  The final touches were a 1 1/4 inch Antares rack and pinion focuser and a 10×30 Celestron finder, which is the same one that comes with many of Celestron’s smaller scopes, including the six inch SCT.  I’ve found that particular version has a field of view which is bright enough that I can see the crosshairs outlined against a dark sky — a rather rare trait, but I’ve got several of them, and all of them have that uncanny talent — and you can frequently find them on the used market for about $25.00.  I believe the lens and cell cost another $25.00, the tube was somewhere around $10, and the focuser was about $45 — and the full container of yogurt was about three bucks.  That all comes to right at $108 — not bad for a great little 60mm scope.

And that brings us to eyepieces.

The Televue green and black actually make a colorful match with the Celestron orange and black!

We’re only going to use four for these tours: three Televue Plössls — 20mm, 15mm, and 11mm — and an old orange-lettered, magical 7.5mm Celestron Plössl.  We’re not attempting to ferret out faint photons and elusive secondaries trapped at 200x in the glare of shimmering diffraction rings — that’s done better with larger apertures.   The idea here is if whatever we’re chasing can’t be seen in the 7.5mm eyepiece, then it’s out of range for the purposes of this tour.  If you want to torture yourself with dim views at 200x, I’ll look the other way.  That’s not to say it can’t be done in a 50mm or 60mm scope — I’ve done it more times than I can count — but my eyes have always rebelled at the visual torment I was forcing on them.  You won’t be able to resist trying it, anyway, so there’s no need for any encouragement from me.  😉

But the intent here is to see what can be seen in scopes of small aperture at reasonable magnifications — and without investing a fortune in eyepieces.  I like the Televue Plössls, but GSO or Meade or Orion Plössls will do just as well, as will University Orthoscopics, or the older Celestron Orthos which can frequently be found on the used market — or just use whatever you have on hand.  You can even mix up the brands and types — nothing is carved in stone here.

This series is also written with the beginner in mind, or at least those without a lot of experience at the eyepiece.  So I’ll categorize each star we look at as easy, intermediate, or difficult.  Some will fall into two of those categories for various reasons, which will be explained as we go along.  And I’ll even include a few observing tips for a nominal fee — free!

In fact, I’ll throw in one tip right now.  Unless you’re one of those rare people — and there really are a few of them — who can observe from a standing position and remain absolutely motionless over the eyepiece, sit down and make yourself comfortable!  It is absolutely amazing how much more you can see when you’re comfortably seated at the eyepiece.  A chair with an adjustable level seat is the best investment you can make — it will literally have an astronomical effect on your observing enjoyment.  You’ll see things from a seated position that you’ll never catch the first glimpse of when standing up.  An excellent example of that is the Polaris secondary, which is discussed in the second tour in this series.

And if position angles and celestial directions make your head spin and cause chronic spatial dislocation, you might want to read Greg’s post on the subjects here.  Some time invested in reading it slowly and carefully, and going back over it a second and third time — or at least until you have a good grasp of its contents — will make your time under the stars many times more enjoyable and rewarding than it would be otherwise.  Without a basic acquaintance of celestial directions and motion, you’re likely to feel like you’ve been dropped into the middle of a large city at night with no map.

So enough of the introductory information.  Put on a coat, grab your scope, and let’s get going.

Oh — don’t forget your Star Splitter hat.

You’ll never get the hang of this without that hat.  😎

Tour number one starts  …………………  here!

A TV-85 Meets Porrima

1AM, April 30th, 2011

The TV85 caught napping in the afternoon sunlight. (Click on this and any of the photos below to enlarge)

It was a dark and clear-ish night when the stubby white tube of the TV-85 peered up from the tripod it was perched on and spied a star being chased across the meridian by Saturn.  Slowly and smoothly it pulled its lens away from Polaris and rotated 180 degrees to the south and slid down the sky in several degrees of declination until it spied its target, Porrima.

It turned to its four-legged assistant, Herr Klaus, and asked for the 10mm Radian.

“Let’s start at 60x just to see what we can see, please.”

Herr Klaus handed the eyepiece over to the operator. “Woof!”

“Hmmm, interesting whitish star, maybe a bit elongated,” the 85 replied.  “Let’s try the 5mm Nagler and it’s 120x, Herr Klaus.”

“Woof, woof, gggggggggrrrrr-woof!” replied Klaus caustically.

“So you think that’s too much magnification?” the 85 asked.  “Well, could be, but let’s try it anyway.”

Klaus plopped the 5mm into the outstretched hands of the operator, who slipped it silently into the diagonal.

“Mmmm, nice,” said 85. “It looks like it really wants to come apart.  Not quite there yet, but it’s clearly close.  How about that Astro-Tech 4mm Plössl you’ve got over there, HK — pass that black barreled beauty up here, please.”

“Gggggggrrrrrr-wwwoooooffff ggggrr woof woof!” HK responded emphatically.

“Yes, yes, I know, 150x may seem a bit much for these sub-average seeing conditions, but please let me have it if you don’t mind.  I appreciate your canine intuition, but trust me, I’ve been at this a bit longer than you have.  And I do believe my Nagler heritage puts me more in touch with the intricacies of atmospheric inconsistency than yours.  Please, just provide the hardware and restrict your comments to those which are merely necessary.”

Herr Klaus lobbed this one into the waiting hands of the operator who made a quick catch and another smooth switch at the diagonal.  Then he sat and locked his classic sheep herder’s stare on the 85 with intentions of intimidation.

“Holy House of Nagler, HK, I think I see a bit of black sky between these two stars!  It’s very close, barely even a hair split, but yes, I see it now — nope, it’s gone — wait, it’s back again — gone, now back …… you know what, where’s that 2x Mead barlow?  Let’s try it on the 5mm Nagler since it has a wider field.”


“Kind of thought you would say that, HK.  Look, I know 240x is insane with this kind of seeing, but I have a reputation for success which I simply must uphold.  Now, if you would, please pass the Barlow and the 5mm up to the operator!”

“RAaaaRF-RARF! WOoooF-WOOF!” HK replied insolently.  But being a savvy Australian Shepherd who knows where the food comes from, he plopped both optical devices into the hand of his outstretched master, currently moonlighting as a TV-85 operator.  “RAAARR-woo-RARWWF!”

By this time, the operator was tempted to add his comments as well, but he knew better than to second guess this chattering nabob of Naglerism, so he just slipped the 5mm into the Barlow and fed it to the TV-85.

“Holy Mother of Mead!” The words rolled through the slim white tube, echoed out of the long black dew shield, and passed into the open air and beyond, where they were heard 38 years later in the vicinity of Porrima.

The operator was stunned into speaking at those words.  “Let me have a look at that!”

He bent over the eyepiece and stared silently for several minutes.  Not a muscle did he move, not a tendon did he twitch, not an eyeball did he blink.  He sat and he stared and he sat some more and he stared some more.

Finally he spoke.  “Well, Mr. 85, I gotta hand it to you.  Remarkable.  Fantastic.  Unbelievable.  Look at this, Herr Klaus.  Two white globes vibrating against the blackness of interstellar space with a very small but definite slice of black sky between them!”

HK knew the image in that scope had to be vibrating up and down so much it would make him as nauseous as the time he tried to eat sushi.  A chattering black and white tube and a star-struck master wound up tighter than a gnat’s posterior stretched across a rain barrel, not to mention being under the 85’s influence  —  he had had enough of this.   He turned and trotted over to the door, pulled it open with his right front paw, stalked back into the house in disgust, plopped down on the floor with an emphatic thud, and thought about how good a dog bone would taste right now.  “Humans and telescopes — about as bad as cats and rats.”  He closed his eyes and went to sleep.

Meanwhile, out on the observing deck, the master sat and stared while the 85 kept the photons focused.

Both scope and human quivered with intense delight in the dark of night under the spell of those dual globes of glowing white light.

They were still there an hour later dripping with dew when HK woke up.

Saturn and Porrima in western Virgo at 10PM on May 2nd, 2011. Click on the chart for a larger view. (Stellarium screen image with lables added).

Star splitting with a pen knife – OK a 50mm F4.1 Little Rascal ;-)

Little Rascal aka Sparrow Hawk aka Stellarvue SV50 with a 6-3mm Nagler zoom and mounted on a Universal Astronomics MicroStar alt-az.

This little dude should not perform that well! I mean, it’s not just that it’s a 50mm. I have a 50mm Tasco I love – but that’s an F12, a much different beastie!  This is an F4.1 achromat  so the focal length is  just 205mm. It is nothing but half a binocular – a glorified finder –  glorified because it has a helical focuser and will take a variety of 1.25-inch eyepieces – and it’s a Stellarvue.  But it’s even using a diagonal prism so you get a RACI and prisms aren’t known for handling power well.  Oh – and it’s a terrific finder and Stellarvue sells a slightly different version of this as a finder.  They’re great. But asking a scope to perform well at 9X is one thing. Asking this kind of fast scope to perform well enough to split Castor, which requires relatively high power, that’s quite another.

Yet I won’t keep you in suspense – it passed the test. Using a 6-3 Televue zoom which at 3mm was yielding  68X it delivered a lovely image of the  the Aa and Ba components of the super double, Castor. (For more on Castor see this post.) But I didn’t  start with Castor and I knew this could do fairly well in any event. I have owned three of these, but in previous tests some time ago I had decided that 40X was its practical upper limit.  I was wrong.

What inspired me to grab this for some early morning star splitting was a debate I have been having with myself – and boring John with – regarding binocular telescopes. (I tend to get super-focused on a subject like this and drive everyone around me crazy, starting with myself.) In this case I was looking hard at the Garrett Optical 70mm binocular telescope that takes 1.25 inch eyepieces and includes this curious note in it’s web site description – “you always have the ability to expand your magnification range by inserting virtually any 1.25” telescope eyepiece from 40mm down to about 9mm.” Hmmm. .. since this is a 70mm F6.2 that would put a limit of about 48X. How much enjoyable star splitting could I do if I were limited to 48X?

To answer that question my first thought was to use an 18mm eyepiece in my Unitron 60mm – that would give me 50X.  But I would be comparing an F15 achromat with an F6.2 and that didn’t seem fair. That’s when I thought about the Little Rascal. It had all the potential fault points of the  binocular telescope and then some – 90-degree prisms rather than mirror diagonal – very fast achromat – and, of course, apparent difficulty in using really high power.  I don’t know, but I suspect the limit Garrett seems to be assigning here might reflect the difficulty in aligning two telescopes at high power. That would not be a problem with the Little Rascal, of course.  So I will assume that at 9mm – 48X – the Garret can still deliver a sharp star image.  My quest then was to develop a feel for what I could see  at these low powers using a similar instrument. (I have this thing about using two eyes – really want to try it – but the price is steep. I’ve already explored binoviewing and for various reasons that doesn’t work well in my situation. )

So – it’s 19 degrees out. That’s cold. But my enthusiasm for the test is running hot. I decided to start easy. Mizar was well placed in the East as the Big Bear clawed his way up the morning sky. I put in a 24mm Takahashi (8.5X).  Mizar and Alcor split, of course. Heck, people with better eyes than mine do this without a scope. I could also see the third star that’s not part of this famous pair, but turns them into a memorable triangle.  But I couldn’t split Mizar itself. Went to a 12.5mm Tak – 16X – and got a solid hint of a split of Mizar. These two are 14.3 seconds apart and magnitude 2.2 and 3.9.  OK – 10mm and it splits! That’s 20X and fits what I read in one of Ed Zarenski’s wonderfully detailed and scientific binocular reports on Cloudy Nights. Essentially Ed found that most binoculars are limited in their ability to split stars by their power, not lens diameter. And at 20X the best you could hope for was a split of stars separated by 7-10 seconds of arc and, of course, even that depends on the difference in magnitude between the two stars. So it’s know real surprise that with a 10mm (20x) it splits, with a  7.5 mm (27X) the split was very nice and with a 5mm (40X)  it was super! Great start.

Orion was over in the west, sohow about the Trapezium? I grabbed the scope and walked to the front yard where no house or tree blocked the view. Uh oh – lower than I thought. A bit less than 15-degrees above the horizon. This would not be easy. Even when clear that’s a lot of atmosphere to look through. But I discovered something here. Having gone portable – the first observation was from my deck where I have observing chair, table and plenty of eyepieces – I found the Little Rascal would work with an 24-8 zoom and a 6-3 Nagler zoom – so I didn’t need to carry much with me to pretty much cover the reasonable power range.  Boy – talk about grab and go! I wss using this on a Bogen with a Universal Astronomics MicroStar mount. That was overkill and a tad heavy. I could have been using a light weight tripod with pan head. Or maybe not at these high powers? Hmmm – just as an aside, I did test a lighter weight rig the next night. I just put it on an old photo tripod.Here is is trying to look big and confident next to the 60mm Unitron.

Little Rascal on alight weight photo tripod looking a little larger than it really is, perhaps, because it's in the foreground of this shot with the 900mm focal length (4.5 times the length of the Little Rascal) Unitron in the background.

But the Trapezium low in the sky, was difficult. I couldn’t see anything worthwhile with the 24-8 zoom. With the 6-3 I got a split at 3mm – 68X – but for this test I really wanted a split at 4mm (51X) or a bit less. BUT – the issue here wasn’t so much the separation between the stars  – the closest pair int he Trapezium are 7.5 seconds. The problem was not enough light grasp when looking through that much atmosphere.  I could get a hint of more than one star at 5mm  (40X) even. But this was not a satisfying view. Have to try it another night when Orion is higher. but Castor is still high right now – about 60°, so no problem there.

Again, lack of light grasp kept Castor Ca out of the picture. And remember, the brighter  pair is magnitude 1.9 and 3 and split by just 4.2 seconds. That’s a serious challenge for this little scope, but with the 3mm (68X) it was absolutely charming. It barely split at 4mm (50X). Perhaps the 70mm binocular telescope could do better. Then again, they make a 100mm that’s similar and  could take higher power and …. oh my. This could end up costing significant bucks. I need to remember how much fun I’m having just testing this idea without spending any money 😉

OK – if Castor splits, why not Algieba?  Back to the deck – and in the house to warm up and write a few notes, then back out to try Regulus, Algieba, and Leo’s double double.

First up, Regulus. And it’s reasonably easy. No trouble with the separation, of course – that’s 176″ – but we’re dealing with a magnitude 8.2 star  that even at that distance is going to suffer some from the glare of the 1.4 mag primary.  At least I assume that was the cause. In any event,  using 8mm (26X) I had a split, but the secondary was so faint I needed to quickly sketch it, then check it against the PA which is 308° to make sure I wasn’t fooling myself. I wasn’t. It split, but not in a way to excite me.

Now for Algieba. I love this star as much as Castor, though it doesn’t have such a fabulous back story, though the colors are wonderful.  In terms of difficulty it should be just about the same as Castor – the separation is 4.6″ and the magnitude difference is 2.4-to-3.6. But it will not yield. It’s actually a bit higher int he sky than Castor was, but I think the seeing – which was above average when I started – is deteriorating. Otherwise I have no explanation. I was using the same scope and same 6-3 zoom and I just could not get the clean split I had seen with Castor. Ah well!

Now for Leo’s double double – charming! Using 20X-40X I got an easy split. Of course, these stars are all orettyc lose to one another in brightness and the closest of the two piar is separated by a comfortable 29 seconds of arc.  So i didn’t view this as a challenge. I really wanted to evaluate the aethetic of seeing it with this power and withr elatively little light grasp – and I liked what i saw. I can’t explain why I liked it – it’s just that the gestalt was appealing to me.

Last on my list was Cor Caroli, a long-time favorite that I suspected would be easy and it was. The separation here is a comofrtable 19″ – the only challenge is the difference in magnitude – 2.9-to-5.5. But it wasn’t a problem, It split at 20X and was real nice at 27X.

So the bottom line is this. The Little Rascal is a fun telescope. With the right conditions and eyepieces you can push it’s fast lens to higher magnifications than I thought, though we’re still only talking 34X per inch – a good long focal length refractor will do twice that. It also has some issues with not all eyepieces coming to focus in it, though I had no problem witht he Taks and the two zooms. But I would not recommend getting this for double star work. It’s just fun to know you can press it into duty in that capacity and it’s light weight and small size can’t be beat when you want something, quick, easy, and incredibly transportable – plus it has an incurable case of the cutes.

What I learned

And what did this teach me about binoculars as double star tools? Well, I suspect you just cna’ttake themr eal seriously – though there is a deifnite advantage to using two eyes and that has not been tested here.  However, I did try some of these same stars the next morning using 20X80  and 15X70 binocular mounted on a Parallelogram mount.  First, a mount is absolutely essential. Second, I had real difficulty bringing the 20X80 (they’re i an inexpensive pair) to sharp focus. The grease in them didn’t like the 21-degree temperature any more than I did. My test stars were the Leo double double. I didn’t get a good split until I switched to the 15X70s – also an inexpensive pair, but these had been in th ehouse and the grease was warm 😉

I got a nice view using them mounted and both pair split at 15X. The 70mm objectives showed me all the stars, but not to great advantage. I liked the higher power view in the 50mm better.

Bottom line? Something like those Garrett binoculars mentioned near the beginning of this post would be real nice and with 90-degree prisms they could go on any sturdy tripod making them simpler than using a parallelogram mount. But with my interest focused on double stars i don’t think I could justify the cost.  It’s the implied power limitation that stops me – and I think in practical terms that’s a real limitation you can’t get around because the focal length is just too short.  with doubles we generally want long focal length because we are pushing our scopes to the highest power that the atmosphere will allow us.  So I  had fun with the Little Rascal. And I’ll use it again. but mainly what it did for me was scratch this binocular itch enough so I can put that idea aside and cous on some other needs that are high priority to me, such as simple clock drives for EQ mounts that hold small – but long -scopes.