Archive for the ‘Open Clusters’ Category

Wow! Now that I like! Mintaka in the 10X30 IS Canons. A bright, flaring second magnitude star with a little pin point of light nearby.

What’s the big deal, you may ask?  Mintaka, the western most of the three stars in Orion’s belt, is an easy split, as I wrote in some detail here recently.  Sure it is – in a scope. The separation is a whopping 53 seconds of arc. But let me tell you why it has stymied me over and over again in recent weeks – in fact, ever since I wrote that post I’ve been trying, at every opportunity, to split it with binoculars. But even the 15X70s when mounted haven’t done the job for me.

The reason is simple – there’s 4.6 times difference in magnitude – 2.2 for the primary and 6.8 for the secondary. That means the primary is about 58 times brighter than the secondary. And as far as I’m concerned I haven’t met the binocular yet that will give a nice, round version of a second magnitude star. This may be me. it may be conditions. Or it may be the binoculars, but that’s the way it is.  But the Canons come closest to delivering that goal – maybe in part because with 30mm objectives they just aren’t delivering that much light.

So what I at last saw – and I was able to repeat it after a 15 minute break – was a bright, dancing Mintaka  with just a faint dot of light next to it – and at just the right position angle, so I knew I had it.  I then tried the 11X56 Garrett Opticals and the 15X70 Celestrons – mounted – with no luck. So this is a big score for the 10X30IS.  And I’m having a ball.

News Bulletin:While still drafting this I had an email conversation with Ed Zarenski, the guru of all things binocular, and he threw some real light on my problem – in a word, astigmatism.  And the above is the perfect example of it. 

He wrote:

Simple astigmatism in the eyes is most affected by the size of the exit pupil.  Mine kicks in at exit pupils over 2mm.  So I have to wear my glasses with all binoculars, but not for scopes at 100x or so.  Astigmatism will prevent you from ever achieving fine focus.  That would have a significant affect on your ability to focus on doubles.

 Bingo! The exit pupil for the 10X30 is 3mm, the 11X56  5mm , and the 15X70  4.6mm – or in that ball park. I don’t trust the numbers on inexpensive  binoculars. But the trend is obvious – the stars get sharper for me as the exit pupils get smaller. In general, high powers results in small exit pupils, though it depends on the object diameter as well – you simply get the exit pupil by dividing the power into the objective diameter.

So do I have an astigmatism issue? I’m not positive, but this certainly seems to indicate it. i do remember that my ancient (c. 1960 ) copy of  “The Amateur Astronomer Handbook” by James Muirden has one of those astigmatism test of radial lines pictured in it  and also says  “luckily, astigmatism makes itself really objectionable only when low magnifying power are    being used.” Which, of course, is what Ed pointed out with the exit pupil.

 Anyway – when I look at that radial pattern the four lines nearest the vertical are much sharper – bolder – than the lines nearer the horizontal.  Wasn’t that way the last time I tried this test – about 1967 😉

Truth is, I suspect my astogmatism has been there – I think I have heard words in the past from the doctor like “slight astigmatism” and so he has not recommended glasses because it was slight – but I suspect it has gotten worse with age and while in normal situations it still doesn’t present a serious problem – in this special situation it does.

OK – back to the excitement of splitting Mintaka in binoculars. See, as someone once said, it’s all relative. It doesn’t matter what instruments you use, or what talents you bring to the show, it just matters that you’re pushing the envelope – that you’re doing things you couldn’t do before and you thought you couldn’t do now, given what you had in hand.  That’s what makes it exciting. So for me each instrument opens up a new universe and there’s a fresh sense of exploration.

I had two other examples in this session. The first  took me back to the Pleiades and its brightest member, Alcyone. When you look at this star in a small telescope at low power two things jump out at you: on one side there’s a wonderful cascade of half a dozen stars – and to the other side – sort of the inside of the Pleiades – there are two 8th magnitude stars that form a triangle with  a third, brighter one, 24 Tauri.  It is these three stars that I have been trying to see with binoculars and until now I could only dig out the sixth magnitude star. but on this night I also pulled out one of the others.

There are several other binocular doubles in the  Pleiades, some ridiculously easy, but quite nice.   These include the very easy Atlast and Pleione – 27 and 28 Tauri.  But there are several more challenging ones. Here’s a working chart I’ve developed for my own use.  I have a pair of 20X60 Pentax on order – I purchased them because they get good reviews, but mostly because  of the 3mm exit pupil. I think they will work better for me and my astigmatism than the usual 20X80, at least when it comes to doubles.  (Yes, I’m going to see the eye doctor and get a new prescription, but I really don’t look forward to wearing glasses while observing with binoculars, though it may be the only solution.)

Here’s my working chart of the Pleiades showing key binocular doubles. Fidning them is a good excuse to spend some serious eyepiece time with this most beautiful of clusters.

Click image for larger view - developed from Starry Nights Pro screen shots.

While in the neighborhood I decided to see if the 30mm objectives could dig out M1. The answer is barely.  I had to check the charts to be absolutely sure where it was. It was a bit easier with the 11X56 when mounted. It was a whispy ghost, barely detected in the 10X30IS.  On the other hand, the nearby “Thirties” were  a piece of cake – that’s M35, M36, M47, and M38.  Oh, and I swung over to “ET”  – the Owl Cluster in Cassiopeia and have to admit that most of what I saw was the nice binocular double that are ET’s (or the Owls) eyes.


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Windy, cold, but clear! I’ll take that any day over the muck we’ve had recently, though I must say seeing was poor and the older I get the less fond I become of cold. But what was keeping me warm last night was the fun of opening up the 30mm Universe – the night sky as seem through 10X30 IS Canon binoculars. It’s awesome.

Now I know a 30mm objective seems small, but here’s a summary of what I saw in a series of brief observing sessions in both the evening and early morning hours. (Yeah, I did a lot of going out for half an hour,then coming in and studying charts while I warmed up.)

In Draco I started with Nu, got a clean split (60″ gap) and so went to the fainter, 16/17 Draconus. Another cleansplit. Here the gaps is about 90 seconds. So I went to the more challenging Psi Draconis which I have not split before and has just a 30 second gap and despite passing clouds and unsteady skies I got “kissing” stars which occasionally steadied enough to give me a hairline split

Went to 56 Andromedae, which I had split several nights ago, and found it easily – and it splt very easily – but my real goal here was something more subtle – the open cluster NGC 756. And I found it – a faint sprinkling of star dust with two or three stars that easily stand out. But this is a real rich area of sky as the following chart shows, for it also contains two of the largest galaxies we see – M31, the Great Andromeda Galaxy, and M33, a much more subtle patch of white . So with relative litte movement of the binoculars – afterall, look at thai six degree field – you can go from an easy double stars to a subtle cluster to a great galaxy and to to a more ghostly one.

Click image for larger version - from Starry Nights Pro screens hot.

What I saw, though, does’t capture what I regard as a remarkable – and repeated – experience: One moment you have a star dancing around and then, almost like watching a photo print develop in a tray of chemicals, you realize you’re seeing two perfect stars. This happened more than once and I don’t know if it’s the image stabilization reaching a new level, or just my brain adjusting to the new scene and kicking into gear,

I experimented with the 11X56 Garrett Optical and the 15X70 Celestrons and I have to say, they just couldn’t deliver. The images were brighter, of course, but when push came to shove the resolution wasn’t there -especially where bright stars were involved. They simply won’t quiet down in any binocular I have, but they’re better in the 10X30IS. What’s more, even though the larger ones were gathering more light – and I was using them on a parallelogram mount – they rarely  allowed me to see any more details than the 30mm binoculars. Generally, whatever I could see, I could see with either, though extended objects, such as galaxies, were easier to see in the larger binoculars.

This raises real questions in my mind as to what is the best binocular for scouting and area while star hopping with a telescope. The 15X70s make extended objects pop more easily – but they give a significantly smaller field of view thanthe 10X30s. I need to experiment with this aspect of binocular use more.

What’s fun with Draco and the binos is you can go on a neat progression from 16/17 at 90 seconds, to Nu at 60 seconds, to Psi at 30 seconds – and all with stars that are pretty close to one another in magnitude.

On to galaxy land! Morning with Ls and Js.

After a few hours sleep I returned to observing in the morning and this time my first target was  M3 rising above Arcturus in the east. A quick scan and there it was, an obvious fat star with with crumbling edges among much “cleaner” ones.

This one's too easy - just draw line between Cor Caroli and Arcturus and you'll find M3 a bit closer to Arcturus and with a magnitude 6 star right next to it. (Click image for larger version - prepared from Starry Nights Pro screen shot.)

But I was  interested in bigger – and much more distant – game.  First up was M81/82, the famous pair up behind the bigBear’s ears.  I say that. I don’t know howmany times I’ve seen them – certainly more than a hundred. But I always get lost looking for them despite some obvious clues. I think it was Sue French who said something like the “Big Bear has ear mites.”  That helps. It also helps to draw a line between two of the bow stars in the Big Dipper. But in the typical finder and these small binoculars they can be too faint to readily jump out at you. You need something more and I think I have it – three radily distinguishable asterims in a row 0 a bold triangle, a ragged “L’ and a 7.   The pair of galaxes we want is right off the end of the L as indicated inthe chart. To get in the right area, scratch around behind the Bear’s ears – or use the two bowl stars to make an arrow pointing the way.

I use the two indicated stars to cut across the Dipper's Bowl and get me in the right general vicinity. Then I look for the asterism in the next chart. (Click image for larger version - prepared from Starry Nights Pro screen shot.)

Sigma is actually a wide (19') optical double of fifth magnitude stars and forms a bold triangle with another star of similar brightness. The ragged "L" leads you to the two galaxies and if you see the "7" you know you've gone too far. The galaxies are fainter than the bright stars int hese asterisms, but keep in mind you are looking at objects about 10 million light years away shinning with the combined light of billions of stars.(Click image for larger version - prepared from Starry Nights Pro screen shot.)

OK – traveling 10 million light years or so with objects I can easilyhold inmy hand is a real trip – but I wanted to go deeper and M51 provided thenext step. Seeing the famous “Whirlpool” galaxy takes you  out  about 23 million light years  and it’s a much easier trip – from a star hopping perspective – though the galaxies are a bit fianter and, of course, mushed together – quite different from the M81-82 pair.

Start with Alkaid, the last star in the handle of the Dipper, and head in the general direction of Cor Caroli. We really have two triangles here, as shown, the second consisting of magnitude 7 stars. Since all this fits in the same binocular field as Alkaid it's apiece of cake - that is, assuming your binoculars have a field of 4 degrees or more. The 10X30s I'm using have a 6 degree fov as indicated y the circle.

That encouraged me to take a look at the lion’s hip – Leo was rising in the east and he carries with him a slew of galaxiws, the brightest being M65 and M66 – and they’re also just plain simple to find.  These are my “J” galaxies – that is, I find them because of a pair of “Js” in the sky near them. In fact, the brighter J sort of hooks them.  Here’s what I mean.

Finding the Leo Triplet of galaxies starts with identifying th ebright triangle of stars that represents the Lions rear haunches. One of those is Thea and if oyu get it in your binoculars the two "J" asterisms should jump out at you. The fainter, larger one is there just to fool you - and I've been fooled by it sometimes, especially in a finder that reverses the image. But the smaller, brighter one is actually easier to spot and from there it's clear where the galaxies are. (Click image for larger version - prepared from Starry Nights Pro screen shot.)

Now don’t get me wrong. I didn’t “see” these galaxies. I “detected ” them. Tome there’s a difference. “Seeing” means you can discern shape, texture, and form. “Detecting” means you know the object is there – that this tiny patch of sky is different in brightness from its surroundings, but where you to draw a picture of what you detected it would be an indistinct smudge. So what you see is a ghostly presence at best in such small binoculars, but I felt confident with M66, a little less so with M65 – and I might have seen the third member of this famous triplet, NGC 3628.

This all defies somewhat the common warnings you here about viewing extended objects. M66, which I certainly found easier to detect,  is listed as magnitude 9.7  and M65 a bit dimmer at magnitude 10.1. But in terms of surface brightness – taking into account how spread out their light is – they are both listed close to magnitude 12.5. Now given that I have a darned hard time seeing magnitude 9.5 stars with these binoculars, you would be justified in assuming that I am either crazy, or a liar, if I say I can see a galaxy with a surface brightness of 12.5.

But all that really illustrates is how puzzling this phenomena of sight and faint objects is.  Stephen James O’Meara, observer and writer par excellence, syas in his book “The Messier Objects,” that all three of these galaxies can be seen with 7X35 binoculars! (He wrote that before the time of image stabilization and I am sure he is not using amount for those.)  If that’s the case, then it certainly isn’t ridiculous for me to claim I’m seeing them with 10X30 image stabilized binoculars. So I have confidence that I am seeing what I think I am seeing.  It is also interesting that O’Meara finds M65 brighter and I find M66 brighter – and again, I have some confidence in what I saw because O”Meara also notes that other observers disagree with him and find M66 brighter.

This whole business of what you can see with what is variable at best and the role of magnification and field size and steadiness all complicate the question, not to mention light pollution and the atmospheres transparency at the moment.  So you really have to try these things for yourself. For me, I count it as great fun that with these tiny glasses I easily hold in my hands I have travelled 38 million light years out into the universe to pluck ancient photons from billions of stars. That’s awesome.


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OK – I’ve decided this before, but I have to learn a lesson at least three times before it takes hold: Binoviewing is not for me. Oh – and the Denkmeir “Big Easy” is big, but it’s not easy.

Alright, in fairness to Denk, when they said “Big Easy” I think what they meant is that we’ll sell a beginner package that will come to focus in all the major types of scopes – no need to break out the hack saw and shorten the tube 0f that 100mm APO.  And they did – and it does. But it’s not easy.  As you use this package and attempt to change powers using the various attachments you may find, as I did, that fumbling with these various screw-in thingees in the dark and the cold isn’t that much fun. What’s more, achieving focus isn’t all that straight forward and may call for really major adjustments.

For example, in switching to high power mode in a refractor – 2.5X normal power –  I had to back the focus way out and when I did that – given the weight of the binoviewer – the scope went out of balance so I had to change its position in the clamshell. So changing power in this case meant:

  • removing two eyepieces and replacing them with two others
  • removing the binoviewer from the diagonal and replacing the “nosepiece” with a different, screw-in “nosepiece”
  • loosening the clamshell, sliding the scope forward, tightening the clamshell (repeat until it balances)

Right – and in mono mode you would simply swap one eyepiece for another.

Just call me Cyclopian!

That’s a big price in what Pooh would call “bother” to pay for being able to use two eyes instead of one.  Makes me feel a lot more comfortable with the habitual, one-eye approach.

But what if I limit the use? What if I say I’ll just use this one with the TV85 at  relatively low power and treat the combination like a super sharp binocular? In this mode I simply go with the low power view using the 25mm Plossls.

Well, the field’s pretty small for a binocular, but I can live with that and if I really like this idea, I could put a couple 24mm Pans in there for another $200 or so. That would give me a wider field – but . . .

What about the old business reported by many that the binoviewer cuts the light in half? You know what? It does!  OK – I know this is controversial, so breathe through your nose all you binoviewer fans. I can’t speak for anyone else, but I spent a whole lot of time this evening with the Pleiades – particularly a little segment between Alcyone and the center of the cluster – well – that little arrow asterism near the center.  Right here:

Click image for larger version - prepare from SkySafari screen grab.

There’s a triangle of  twelth magnitude stars near there and guess what – I could see them while in binoviewer mode with the TV85.  (M45 was near the meridian and transparency was average – maybe a bit better.) That’s good – except, I could see them just as easily with the 60mm Unitron set up next to it!  (I could not see the 13.57 star noted in either scope.) Bottom line – as near as I could tell there wasn’t any difference in the light reach of the 60mm  Unitron and the 85mm Televue.

This, by the way, is exactly what the math shows. Figure the area of the 85mm lens. (Just square the radius – you don’t need to throw pi in there.)  Now divide by two and take the square root of your answer. That give you the radius of an objective that would produce half the light gathering area of the 85. Or in math-speak: 42.5 squared is 1,806 – divided by two is 903 and the square root of that is 30.05 – times two and you have a 60mm objective. Don’t you love it when the geeky math actually shows you the same thing as your eyes and common sense!

Downsizing the TV 85

So by putting binoviewers on my TV85 I was turning it into a TV60 – as far as light grasp goes. I should hasten to add – and this was obvious on Jupiter – that the added resolution of the 85mm is still there despite the binoviewer, so Jupiter certainly looks better in binoviewer mode in the TV85 than it does in the Unitron at a similar power. Which is why the common wisdom is that binoviewers are really great on the Moon and planets, giving you a sense of 3D even though at astronomical distances that really isn’t the case.

So – why not just limit binoviewing to the Moon and bright planets – and bright doubles?

Maybe. It’s tempting. The binoviewers do a good job on bright objects – but I did run into some unexpected CA problems which I can only attribute to the binoviewer – or maybe my difficulty in reaching precise focus with them. I must admit, at high power I actually had to ease the binoviewer out of the  diagonal a bit, then clamp it tight, in order to reach focus  in the TV85. Different eyepieces might have solved this problem. But that’s really no way to hold the system together and I had no remaining outfocus, so let’s ignore that CA business.  It wasn’t there, for example, with the 25mm Plossls – just with the 17mm Plossls.  But whatever the cause it was irritating.  And by that time my patience was wearing thin. See, when it’s clear I like to observe – not screw with equipment.

And really – I am neither a planetary or lunar observer. I look from time to time and enjoy both activities, but I don’t think that is reason enough to have $400-plus  invested in binoviewer and eyepieces.

Oh – a few other notes from this observing session – which was really three sessions starting at  about 9 and ending after 2 am with significant breaks between as clouds came through.

  • I could not split  Polaris with the 60mm Unitron or the TV85 in high-powered binoviewer mode. I could split it with the TV85 in cyclops mode.
  • I could not split Mintaka – frustrating – with the 10X30IS Canons, or the 15X70 Celestrons handheld. (The mount for the Celestrons was in a shed 100 feet away and I was too tired at that point to go get it.)
  • I could split Mintaka with a 50mm F4 and a 50mm F12 on a double mount – but what I was really trying to do was to get a handle on the linear size of the star image   – something that the optical experts says is controlled strictly by the focal ratio of the telescope.  But I had a brain freeze about this time – it really w as time to go to bed – and I just couldn’t make good sense of what I was seeing or even remember what I thought I saw when I went to making notes.
  • Still, the last thing I did was a quick tour of familiar sights with the 10X30IS binos – I do like them – and I meandered long enough to get some idea of their lingering magnitude -in the neighborhood of 9. I was checking what I think of as the “house” in the Hyades – what Daphene calls the “bell.”  Here are the test stars.

Screenshot from SkySafari on my Ipad showing the 8th and 9th magnitude stars I was able to note with the 10X30IS binoculars. Less tired and more patient I'm sure I could go deeper with these. Click image for larger view.

Actually the number I’m getting are pretty fantastic – enought o make me wonder about whether SkySfari is giving me the right magnitudes. Of course,t here are various opeinions on limiting magnitudes for different size instruments. Here’s what respected observer Clay serrod has to say about it on his web site:


There are formulae available in all the books that I will not bore you with; from that formulae, I have prepared a MEAN value, an average of sorts, of all of them and offer the list below. My 32 years in astronomy has shown me that this list is, indeed, VERY close to actual performance.

Under the darkest conditions (see below)

            HUMAN EYE             - 6.5            5.0"         - 12.8
            2.5"                 - 10.5            6.0"         - 13.2          
            3.5"                 - 11.4            7.0"         - 13.6
            4.0"                 - 11.7            8.0"         - 13.9

Hmmm . . . 30mm is about 1.2 inches and if 10.5 is the limiting magnitude for 2.5-inches  I have to think 8.7 is a respectable figure for 1.2 inch binoculars. Of course there are two of them, so let’s multiply 30mm by 1.3 – that gives me 39mm – more like 1.5 inches. well, 8.7 is good there too.  (That 1.3 multiplier is another compromise – binoculars increase the light grasp over a single scope by a factor of 1.2-1.4 accoridng to conventional wisdom.)

What I’m more surprised at is my 60mm (and the 85 inmbinoviewer mode) delivering a magnitude 12 star when Dr. Sherrod’s compromise chart above would set the limit at more like 10.5 – that’s a huge difference.  And Starry Nights Pro has the same, or slightly lower magnitudes for those three stars.

So what’s going on? i think there’s just too many variables and so this limiting magnitude business is all over the charts. For example, according to another web site with a very sophisticated looking formula I should see significantly deeper – and yet another one has me seeing deeper than I  should.  None of which matters for what I was trying to learn with the binoviewers. The simple truth is they made the 85 perform like a 60 – no matter what the absolute values involved, this was a side-by-side test.



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, , , for example, I dressed as if it was going to be below freezing – way below freezing – and I stuck a pair of chemical handwarmers into an extra pair of gloves on my pockets – and the temperature went from 36 at  3:30 am to 39 at 5:45 am when I came in, which is just the opposite of what I expected. Good!

But my enthusiasm for binoviewers on the LT-8 in the observatory dininished, not because of the light loss – I had anticipated that and really, it just doesn’t seem that bad – but because of several things I didn’t anticipate, such as:

To change powers you screw in different nose pieces which is:

  • more time-consuming than changing eyepieces
  • more difficult to do with gloved hands than, say, changing eyepieces

In fact, removing, then placing back in the whole binoviewer is the equivalent of changing eyepieces, so the fooling with threaded nosepieces is all extra work. (This, I should add, is why Denkmeir sells a sliding switch that does the same thing in a no hassle way – but at a significant cost, of course.)

And perhaps as important, in the crowded, six-foot diameter space of the observatory, having 4-5 inches of binoviewer projecting from the diagonal really does cramp your style and just sits there as something begging to be bumped into with an elbow or shoulder.

Plus that added length in the diagonal does change the height of the eyepieces significantly. For exmaple, my first target was the Orion Nebula and it was just above my house at about 30-degrees altitude and that put the eyepieces  so high that I had to put a thick boat cushion on top of my pneumatic draftsman stool which was already raised to its highest level. Yet on a high altitude object – I went to M67 next – the stool was too high at its lowest setting and so I had to shove it aside – and there is not much “aside” room in this little space – and use the lower setting on a normal office chair.

This problem of space has haunted me since I built the observatory  twenty years ago. (Well, had it built – I designed it, though, so the space issue is on my shoulders.) It works OK with  an 8-inch SCT in alt-az mode. But that’s it. Nothing larger. I once had an 11-inch SCT in there – no way.  And I’ve tried all sorts of other scopes on all sorts of mounts and they just are too cumbersome with the exception of small refractors on the UA T-Mount – that tends to work.

Hmmm . . .  maybe I need to try the UA T-Mount with TV85 in binoviewer mode?

Oh – that reminds me  – I did try the TV85 straight through in binoviewer mode. Interesting, but not really successful.  Maybe I need to give it another chance. It just seemed unusually awkward.  I was using the T-Mount on the pier in the Observering Shellter. This was something suggested by the previous owner. You discard the diagonal and put the binoviewer in the scope with nothing but the hollow nosepiece on it – same as you do for medium power in the SCT. It couldn’t quite come to focus when I first tried it, so I switched to  a very low profile 1.25-inch adapter  and it worked fine.  But the views didn’t knock my socks off – probably because there was a lot of high clouds and nothing resenbling either average seeing or transparency – in fact both sucked to the point that when I started about the only thing visible to the naked eye was Jupiter with a haze halo around it.

Which reminds me – this experiment was done on Thanksgiving  night around 8:20-9 pm – six hours before the experiments in the Observatory with the LT-8. And before those I had been at Sarah’s house in Rochester and invited my granddaughter, Amanda, out to take a look at Jupiter through the 10X30 IS Canons. Great!  We both could easily see three of the Gallilean Moons using those little binoculars. Now I have seen them with binoculars of similar size, but none as small as 30mm and with the image stabilazation I saw them more clear than with any handheld binocular – and so did Amanda.  So that was an unmitigated success and once again speaks well for the little binos as a keeper.

But this straight through business with the TV85 needs a better trial, I think.  What I like is it gives me a nice step up in power, at least, from the 15X70 binos.  If you do the math the light grasp of the two instruments should come out very similar. That is, being a binocular the 15X70s should act like something closer to an 80mm scope. And given the light loss in the binoviewer the 85mm probably acts like something closer to a 75mm scope. But in term of power, when used straight through witht he 25mm Plossls the 85 is probably delivering about 25X – and doing so through a superb 85mm  lens, so it really should give me the best, high-power binocular view available.

Sidenote: Actually, if you do the math according to the way some figure, the 85 in binoviewer mode is equivalent to a 60mm scope. See, the binoviewer splits the light from 80mm lens in half. So if you take the area of the 80mm lens, divide it by two, then take the square root of that and multiply by two you come up with a 60mm objective.  Now I’m going to have to try it side by side with a 60mm to see if this is true.  It sure doesn’t seem like the light has been cut that much.  But. . . there’s another line of thought that says you are getting two eyes worth of light and your brain recombines this.  I like that idea – except – and this is a big except –  I’ve done some very casual testing where I close one eye and look through just one side of the binoviewer and the image doesn’t seem to dim.  So this really does need exploring.

Bottom line – I’ll experiment some more with it on that mount in daylight and see if I can get around the apprent awkwardness I found last night  – afterall I was tired, rushed, and conditions were terrible.

That said, this morning I was neither tired , nor rushed, and conditions were not so terrible – though transparency was poor and I couldn’t believe how dew attacked all glass surfaces the second they were exposed – even though they had been sitting in the cold of the observatory all night! Remove the lens caps and instant dew problems. That was unexpected and so my first problem was to remove the dew. And it kept coming back. For example, when I looked at Castor I was puzzled by the fact that I could barely see the third star in this easy triple. I took that as evidence that the binoviewer was eating up more light than I thought. Looked like a 60mm cyclops view, really. So I switched to cyclops mode using the same 25mm eyepiece. Oops – no third star this way – or a very faint one. Time to clean the dew off the objective again! Yep – there’s the third star – easily seen whether in cyclops or binoviewer mode.

Bottom line. I’ll give this some time. I’ll try it with different instruments. But last night and this morning things did not go as expected in binoviewer town, so stay tuned. And yes, I am not using them yet in the one area where I am sure they will shine – the Moon and bright planets.

Addendum: I fooled around in daylight this morning and after trying different mounts and chairs I came up with a configuration that works. Having done that, however, I’m now really thinking “so what?”  Why am I so bent on using this thing straight through when it is so much more comfortable to use in a diagonal?

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Also, a new observing routine: I have decided to halt my public programs and focus on my own observing projects – something i haven’t done for five years or more. As part of that change, I’ll try to keep a record here since I think it’s always good to reflect on what you’ve done.

True to the CSC, it cleared early this morning, though  just along the coast, and so I got out in freexing temps with terrible seeing at about 4 am.  I had two basic goals.

  1. Assess the performance of the new (used, of course) Canon 10X30IS binoculars.
  2. Make a preliminary estimate of the light loss caused by the new (used, of course) Denk Big Easy  binoviewers when using them on the Televue 85.

I met both goals in about 90 minutes and ended up with very cold hands despite several trips from the deck to a warm, red-lit library.

First, the 10X30.  I had just tried a pair of 10X42IS Canon’s and was unimpressed – that is, unimpressed in terms of their perforamnce relative to their price, so I owned them for less than a week.  The 10X30s are quite different, first in cost – used $245 vs. $770.  Second, in light grasp  42 vs 30 is 1,384 vs 706 square millimeters of light gathering lens – or put another way, using my 5mm dark-adapted pupil as a measure (19.6 sq. mm), that’s 71 eyes vs 36 eyes.  Of course I didn’t do a side-by-side test, but the bottom line is this – I didn’t miss the extra eyes, I didn’t miss the extra quality, and the dollar savings gave me enough to buy the Denks and a couple Plossls!

Truth is, Sky and Telescope binocular guru Gary Seronik says of the 10X30 IS : “I own a pair of these and find I use them more often than any other binocular in my collection. ”

Yep – I can understand why. First, the ergonomics are simply better – they feel right in your hand. Second, they don’t weigh nearly as much: 1.4 pouunds – nearly a pound less than the 10X42s.  Third, you need to hold the IS button continuously – a supposed disadvantage – but I found the placement of the button on the larger binoculars – it’s to one side – awkward and on the 10X30s (just in front of the center focus) intuitive.  With the bigger ones I did a lot of searching when wearing gloves for that button and then wasn’t sure I had hit it, so I would take the binoculars down from my eyes and look to see if the green light was on.  With the smaller ones it just worked naturally and I guess it’s a little noisier or more obvious when it kicks in because I always knew when it was on.

Of course, the big question I think most amateur astronomers have on their mind is can you see anything with the 10X30s? I mean, that’s barely more than an inch of objective – well , a bit more because it’s a binocular, but still darned little. And the answer is yes. Seronik describes it this way in his online review: ” the 10× magnification, image stabilization, and superb optics more than make up for the smaller aperture.”

To confirm this I did a very quick survey of some obvious binocular targets – the Pleiades (30 stars without any effort to see the faint stuff) ; Hyades – really beautiful and easily picking up stars of magnitude 9 and on the bright side of magnitude 10; the “enagement ring” around Polaris; Orion Nebula – really impressive; the three gorgeous clusters in  Auriga – M37, M36, and M38 with no sweat at all; M81 and M82 with no sweat; M51 (Whirpool Galazy) with a little sweat; M65 and M66 with a serious effort. (The cold was already getting to me, so no sweat there, but they weren’t easy 😉

What that means is I can easily use these to aid in star hppping and enjoy quick views and that’s all I expect of them – though I intend to also use them in a binocular double star program.

OK – what about my TV85 as a binocular?  This is interesting. Binoviewers cut the light in half, sending half to each eye. The brain does some recombining. And as near as I can tell no one knows quite what to make of this, nor is there agreement on anything except that there is some light loss – not sure how much.

Well, I really like the idea of observing with two eyes – it feels right and it makes sense. I did it before, but cut it out when I switched into public mode – some people have toruble getting the images together in abinoviewer and everyone  needs to adjust them for interpupilary distance and maybe make a diopeter adjustment as well, so they are too much of a hassle for public sessions. Private viewing is naother thing. the jury is still out, but I want to give them a serious try this time around. Afterall, we were born with two eyes and most of us are fortunate enough to be able to use both all the time. So why not use two eyes while observing? The answer is it’s either prohibitively expensive – though there are such things as binocular telescopes – or there are a host of quality-cutting compromises.

With typical binoculars the compromise comes in making two telescopes work together as one – to do that you need to make the two telescopes “fast” – that is with focal ratios in the neighborhood of F4 – and to sell them you need to make them cheap.  Fast and cheap just don’t go together, so binoculars invariably sacrific quality and can be used only at relatively low powers.  I have a devil of a time getting even moderately bright stars to be pinpoints with even the best binoculars I’ve used.  Use an inexpensive, achromatic, long focus telescope and it’s a piece of cake to get nice, sharp stars.  Use an inexpensive, short focal length binocular and you just can’t seem to get there from here – or I can’t.

Enter the binoviewer. You can use it on any telescope, but there are two big quibbles:

1. You introduce a lot of extra glass into the light path and that creates potential issues with reflections, collimation, and light loss.

2.  You are splitting the light beam in half sending 50 percent to each eye – so some feel you’re cutting the light grasp in half.

I can’t do anything about point one except to use quality binoviewers which the Denks are.  (They make a higher quality one than these which I haven’t yet felt compelled to get.)

I just don’t know what to make of the second point and in the final analysis I guess it comes down to the fact that there will be some light loss and you have to decide if that is important to your observing experience. There’s a trade off here – some light loss for the privledge of using two eyes. So my question is, how much light loss?

There’s actually a third problem I’ll deal with it after the light loss question.

To determine light loss I simply honed in on the Pleiades – they were just above my tree line in the west – and particularly on the stars around Alcyone. I didn’t care about actual magnitudes. All I wanted to do was to find some faint stars with the binoviewers, then examine them in cyclops mode at a similar power and with a similar quality eyepiece.  I was using 25mm plossls in the binoviewers, so my comparison eyepiece was a 17mm Plossl in cyclops mode. (That gave me 33X in the binoviewer and 35X in cyclops mode.)

I located a triangle of roughly 11th magnitude stars and my assessment was simple. I could see them in the binoviewer – though the faintest needed a little averted vision. I could see them more easily in cyclops mode. How much easier? I don’t have a clue. My rough guess is we’re dealing with no more than half a magnitude light loss and probably about half that – but that’s just guessing. Whatever the numbers, it wasn’t enough to disturb me. The view was still wonderful and using two eyes was relaxing.

Thatw as the only real test I did. I did look at M51 and enjoyed the view – but I did not do a comparison. Why? well, that’s the third issue. See  to get the binoviewer to come to focus in the TV85 you have to put another piece of glass in front of the diagonal. That means to go to cyclops mode you have to remove the binoviewers, remove the diagonal, take this piece out of the diagonal, return the diagonal, put in a single eyepiece, AND rebalance the scope – in this case slide it a bit forward on the mount.  Not a real big hassle but on a cold morning I wasn’t enthusiastic about doing that repeatedly.

But that leads to point three – in the TV 85 the binoviewer  delivers either 1.4X or 2.5X the normal magnification.  So a 25mm Plossl in cyclops mode will normally deliver  24X and thus a nearly two degree fov – very nice for the Pleiades, for example. In binoviewer mode that same eyepiece is delivering 33X and something closer to a 1.5-degree fov which really crowds the Pleiades. The guy who sold me this said I can use a 32mm or even 40mm Plossl with it and urged me to do so. I did try the single 32mm Plossl i have and it did give me a wider field. But there’s something bugging me where I thought the size of the prism in the binoviewer limited the low end of eyepieces – but it may not. I need to explore that.

But – if a 40mm Plossl works in it, it should deliver about 20X and a 2.1° true field.   That may be worth it. (The gain in true field isn’t as large as you might think because the apparent field of view on the 40mm Plossl is typically about 44° as opposed to 52° on most Plossls. )  In cylops mode I’m used to the 24mm Panoptic and a 2.8° field of view.  What i found this morning  is not having that extra field is important in finding stuff. The 24mm panoptic made finding things fairly easy – you could point the scope by intuition alone and usually find what you want in the eyepiece. Not so with the smaller fov in the binoviewers with the 25mm pair. So this is something I need to explore if I want to use the binoviewers seriously on the TV85.  And I may.  I was frustrated this morning because I have a red dot finder on that scope, but I almost never use it and it was way off and my fingers were getting too damned cold to fix it, though I tried for a while.

One last note on the TV85 – the guy I bought it from suggested trying it in straight through mode. I think I will – especially since I could put it on the  UA Tmount and use it while sitting down. Could be real cool.

So at this point I’m real happy with the 10X30 IS Canon binoculars – they’re a keeper.  And I feel I have a lot of experimenting to do with the TV85 and other scopes before I will be convinced to go the binoviewer route in a serious way. If I do go that route, then the changes it will generate will sort of travel through my equipment list as if they were dominoes and result in a lot of buying and selling – something I’m addicted to anyway, but I’m not convinced the addiction is healthy.

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Remember a summer evening when you were maybe 12 and you stayed out past sunset? And sunset faded into twilight which faded into night and you knew your Mom would be worried, but you just lay there on the grass, looking up, fascinated as the stars came out?

For me those evenings were filled with a mixture of wonder and confusion. They still are, but on a deeper basis. Last night was such an evening – only colder 😉

But I rediscovered for the umpteenth time the deep pleasure of simply looking up – and I enhanced this by adding a comfortable, swivel beach chair, a parallelogram mount, and a very nice pair of 10X50 binoculars – which in sum led me through a space walk in my new and much larger “backyard.”

It began close to home shortly after 8 pm with Saturn high in the southeast, Mars high in the south, and memories of Venus and Mercury, now well below the treeline, if not below the horizon to the northwest.  Together the four did a beautiful job of defining the ecliptic.  This is particularly true of Saturn and Mars, both just a tad north of it.  But Saturn also is a reminder these nights of where the southeast-to-northwest arc of the ecliptic crosses the more easily defined arc of  the celestial equator. Yes, I really do think about this stuff when I’m out there because I’m trying to develop an intuitive grasp of where we are in the universe  and this helps.

Suddenly it all fit together so nicely. The projection of earth’s equator is an easy one – but the ecliptic I usually find more elusive, but not last night. Then it  just seemed so obvious that these little dots of light – Saturn and Mars – were sitting on a disc – the same disc on which I was lounging in my beach chair in my little gem of a spaceship, Earth.  Here we were on the plane of our solar system where almost all the local action is. I wish I knew how to bottle that experience so I could take a sip of it whenever I wanted. Most of the time all this talk of planes and arcs and planets remains in an abstract world. I understand the words, but they have no meaning at the gut level – last night they did. Last night they they left the realm of mere words and  numbers and were real.

That’s the sort of thing I always seek – but too rarely find. But it didn’t end there. The night before I had enjoyed a brief tour with some 10X50 Pentax PCF WPII binoculars I had picked up recently on Astro-Mart. They give a crisp, five-degree field of view that stays sharp to near the edges. But I quickly tire of holding them up, so for tonight I had brought out the “Suntracker” swivel beach chair – my favorite for binocular use – and a rather battered parallelogram mount made to my specs by a guy in Tennessee  several years ago.  At the time I wanted something fairly short that didn’t crowd my observatory, but now I use it on an old Meade field tripod and in the open.

But what was important here was a new lesson in patience.  I not only was staying away from the DoubleStar mount which had scopes already to go, but I really took the time to get comfortable in my chair,  and get the binos well-balanced.  This is absolutely critical.  I want them to float in front of me and when looking straight up, they should not put any pressure on my face. Then I went out in space. It was a real trip!

My tiny backyard vanished – everything around me vanished – thanks to using both eyes – and I felt I owned the universe. It was my new backyard and I was just roaming around from one familiar spot to another –  M35, 37, 36 and 38 of course – then over to M44 and Mars spinning past, splitting the two donkeys – then down to ancient M67 and eventually over to the Leo Triplet where I settled down for a long look. Yes, I could see M65 and M66 in the 10X50s, but I had to pretty much imagine NGC 3628. Maybe others can pick it up with 50 mm? I feel good if I can see it with an 80mm scope.

And that’s where I eventually went – to the 80mm APO  which I gradually worked up from 16X to 37X. It was on the UA DoubleStar mount with a C8 and I switched to the bigger scope and I swear I saw these galaxies better than I ever had before and I think the reason was simple. No, it was not because transparency was excellent and seeing pretty darned good as well, though that certainly helped. It was because I had had the patience to get totally – and comfortably – immersed in the universe the way I know I should, but too seldom do.  I always seem to think I can cut corners.  What was important for me was to mentally and emotionally get the context down pat using naked eye and binocular, then slowly inch up on both power and light grasp, making each instrument deliver all it could before moving on. Delightful! When it works the way I think it should, this experience is way beyond my skill to express it.

In the final analysis I don’t think any of the equipment matters. What matters is simply learning how to relax.  I’m not talking meditation here – though that’s important to me – but learning to accept the fact that you’re going to take a beautiful night like this and really devote it to just a few objects. (Think of it as going to the Magic Kingdom and instead of hitting every ride in a marathon day, you just go through the Haunted Mansion – several times. [-)

And what was the best lesson of the night was learning – or maybe relearning – how to sit in a chair.  No kidding. I think lying back in the grass and looking up is the most natural approach to the night sky and I’m sure our species has been doing that for thousands of years.

But put binoculars in front of your eyes – binoculars held firmly in a very steady mount –  and it is still so easy to strain just a little and not even know you’re doing it. The position of the binoculars isn’t perfect, so you just raise your head a tiny bit and maybe twist it. The big mistake is you are, perhaps  subconsciously,  trying to bring your eyes to the binoculars  instead of bringing the binoculars to your eyes. Well – at least that’s been my problem in the past. I always thought that when I grew up I’d learn to be more patient. Maybe I’m growing up. 😉

In any event the evening session lasted a couple hours.  If I were younger I probably would have made a night of it. Conditions were terrific. But instead I came in and eventually got to sleep around midnight and didn’t get up again until 3 am. Still, this gave me a chance to repeat the process and extend my vision from the solar system to the galaxy. For once I was back on the observing deck and my eyes had reasonably dark adapted, the summer Milky Way was quite high overhead. The northern parts near Cassiopeia were lost in the light dome from New Bedford and North Dartmouth, but from Cygnus down through Scutum it was terrific. What really struck me was the varying intensity – the big rift you get between Cygnus and  Aquila, then the really bright clouds you find as you hit Scutum. My treeline blocked off the best parts that go down into Sagittarius towards the center of our galaxy, but what I could see was enough to give me a vision much akin to the one in the evening session where I could really see our planet sitting as a lonely speck on the great disc of our solar system with a few other lonely specs, Saturn and Mars.

Now the planets were mostly out of the picture, but that greater disc – this one much puffier, but better defined –  was obvious. And again I found it easy to envision our tiny star as one of millions in these clouds that spiral out from the galaxy core.  In a sense it was disc against disc – one in my memory from a few hours before and running across the sky from southeast to northwest – and a much puffier one now cutting across at a much different angle from northeast to south. Both these define our home – our place in the universe.

I spent more time in the chair not using the binoculars – just captivated by the naked eye vision.  But I at last did a little exploring of the familiar.   I looked for M57 but with 10X I could not decide which faint dot among several was a little blurry, so I swung on down to Albireo.  But  with 10X I could not split it. (Have others been able to with small binoculars?) It showed some gold, but no blue and nothing I could call two stars. So I kept moving eastward until I hit M27 which was certainly large enough to make an easy target.

Next I played with my own little piece of mythology – using the well-known Coat Hanger as a jumping off point. I think it was Bren who suggested that this belonged to the Fox, for the obscure constellation of Vulpecula is nearby – and we have always had fun thinking about this worn out little fox, returning to his den, a bit sweaty, but happy that he had once more eluded the hounds – and, of course, hanging up his red hunting coat on this starry coat hanger.  Having invented that – and I’m laughing at myself here because I am really not a big fan of constellation mythology – I can appreciate how ancient people, sitting on the ground at night, looked at the stars, connected the dots, and let their imaginations go wild.

From the Coat Hanger it was a short slide down past Altair to one of my favorite open clusters, M11. And with the first hints of dawn showing I moved quite quickly to the 80mm, got M11 in view, and then shifted to the C8. This fascinates me. At one moment it looks like a printed circuit board – at another, the streets of a well-planned city. There is something very regular, almost rigid, about the pattern of stars in this cluster that belies its nickname of “Wild Duck.”

The circuit board metaphor works for me, but this morning I liked the city one even better. The single bright star that dominates felt like the Empire State Building to me – and the dark lanes – a blotch really – that enter from the west could be a celestial version of Central Park – and at that point I have exhausted my very limited knowledge of the Big Apple.  But twilight was really taking over and I just had to check on the Double Double to see just how good the seeing really was.

Very good. So good that with the 24mm Panoptic in the C8 – 83X – I was getting a nice clean split of both stars. And they were perfect round dots at higher power in the 80 mm with as textbook clean a split as you can obtain.

Yep – and there’s more of this weather in the forecast for tonight! We’ve been building towards it gradually. Saturday gave clear skies for a while, but really horrendous seeing and not that good transparency. Each night since I’ve had  some hours that were better than Saturday, but none as good as last night. For me, it’s a few hours like these that define amateur astronomy. May we all have many of them!

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More gleanings from recent exchanges on the Club board and  observations made here:

You’re right, Bob – the UFO galaxy is a keeper. Thanks for calling my attention to it.  I followed your “staircase” tonight (Friday) – transparency left something to be desired and there was a tad of interference from the moon, but hey, it was nearly at the zenith, so quite easy.

I was using the 80/8 combo  on the Double Star mount with the 30mm Clearvue in the 80, so I had a 5-degree fov. This easily takes in the Beehive, my starting point, with it’s two asses. I used them as pointers and moved up a couple of fields to Iota Cancri and just to be sure I was on the right star, I switched to the 8-inch. Since it’s a beautiful double – the “winter Albireo” – it was easy to see i had the right star and  now it was just a matter of climbing your stair case for another 5 or 6 degrees and looking for a pair of stars the galaxy forms a triangle with. Bingo – found them and thought I saw the galaxy. When I switched to the 8-inch there was no doubt.  Jumps around on you some, though – seems to benefit a lot from averted vision and as I think you mentioned, has a chunk out of one side from a  dust cloud.  The almost north-south orientation was striking. I can’t say I would have spotted it as a flying saucer immediately, but with that image in my head already, that’s what it looked like. Light seemed pretty even – felt like a chalk smudge on a blackboard.

I switched to the 80mm and with slightly more power it was easy to see in that scope as well. When I really cranked up the power there to 96X it was very easy to see. There’s a little quadrangle of sorts of four 10th and 11th magnitude stars about 10 minutes south of it that I found were a handy marker.

So, while I could see this in the 80mm and it looked quite nice in the 8-inch, I have to admit that it would really shine int he 15-inch which I assume is what you were using. Maybe during the next spell of bad weather I’ll get it back together 😉

Bob commented on this, then added:

BTW, I’m surprised you were able to see both of the donkeys at the Beehive, since I swear that the ISS ran over poor Asellus Australis while I watched with my binos earlier in the evening!  😆  😆 A near-perfect hit!!! Very ethereal to be watching this bright blob of technology through the binoculars and suddenly see the much fainter Beehive racing past the field of view.[/quote]

You sure pulled a lot of stuff out of those murky skies, Bob. But yes, that was a great pass of the ISS – we watched it too thanks to the head’s up from Pete – but in the 80mm and 8-inch and I have to admit, I wasn’t even conscious of the Beehive! Funny – my little lesson of the night was on field of view and I was just too wrapped up in the tracking  – and probably using too narrow a field of view  😳 – to see the little ass get kicked in the – well tail 😆

I had a couple of the “star hoppers” out and I asked them to come a few minutes early just to see that pass. But my plan was to line up the ISS in the Telrad, then jump quickly to the 80mm with the 5-degree fov – then I would hold it in the center of that while the others took turns getting a good look at it in the 8-inch with a 24mm Panoptic – 83X. It worked perfectly and they both got good views, then I switched to the 8-inch – Wow! I could see four rectangles of light, the two outboard ones dimmer and kinda reddish. Best view of the ISS I’ve had so far.  But at that power it is sure moving fast. The DoubleStar mount is smooth, but I felt like I was using a pair of 40mm Bofors and was holding off fighter attacks 😆

Assellus Australis must have had a good laugh, though – let’s see, I think the Space Shuttle missed it by about 136.18 light years – give or take a few fractions of a light second  🙄

I noticed the high clouds you mentioned as we watched the ISS go over. Some of them were thick enough to totally block stuff  – but we still had fun with my visitors learning to track down the two Christmas Trees – M103 and what I think of as the real one over at the tip of the Unicorn.(http://www.wired.com/wiredscience/2008/12/xmastreecluster/ ) Also on the agenda for Rose was ET. Joe wanted to track down M67 – and did – and Rose wanted to go after that obscure little cluster in front of the Hyades – NGC1647  –  and did.

Well not so little – it’s about 30 minutes across -but It really doesn’t make a good first impression! It’s interesting for all its doubles when seen with enough power. But it was also a good illustration of how difficult it is for someone just learning the sky to even know they’ve found an object when they’ve found it. It just doesn’t look much like a cluster. Especially in the 80mm at 15X. It easily sits in the same field as Aldebaran (with the 30mm eyepiece)  and with a dab of moonlight plus the deceptively murky skies she stared at that area for quite a while, looking directly at NGC1647 and not realizing that she was on the cluster.  However, putting the few stars you do see that way in the center of the 80mm and then switching to the 8-inch does reveal it’s true nature.

It drives me a bit crazy, then, to read what O’Meara has to say about this cluster in [i]Hidden Treasures.[/i] He had never seen it either – until his wife, standing in their driveway halfway up Mauna Kea, thinks she has discovered a comet with her 7X35 binoculars! What she saw turns out to be NGC1647. Oh for skies like that! With really transparent one here it would look a little more cluster like in binoculars I guess, but O’Meara calls it an easy naked eye object. Not here!

Hope folks get out tonight and watch the Moon’s close encounter with the Pleiades. It’s going to be murky again, but still should be a nice binocular sight  and I think this is the last such event for several years???  According to Starry Nights software, the view from here should have it just clipping the bottom off that wonderful chain of 7th and 8th magnitude stars that trails down from Alcyone. That should happen between 9:30 and 10 when the Moon will be pretty low in the west. Of course you’ll probably need  a telescope to see those stars so close to the Moon, but it leads with its dark edge. If the weather gives me a break – and the CSC is ambiguous on this one – I’ll be watching.

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