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Archive for December, 2011

I guess most people wouldn’t consider it  a good thing to go to bed at 11 pm and wake up at 2 am in a totally dark house – the power out.

I did last night – well,this morning really. (OK – it was yesterday morning. Took me a while to finish editing this 😉

I couldn’t wait to see if the skies had cleared after several days of clouds and half-hearted rain.  They had ! And no lights anywhere to interfere!  So I rushed to get some clothes on and get out on the deck with the 10X30 IS Canon binoculars – my grab-and-go instrument of choice these nights.

Silent Night, Holy Night

And when I did two things hit me right away – first, the brightness of the stars with the Great Bear rising in the Northeast, his tail pointing to Arcturus which pointed to Spica which in turn was joined by Saturn. And second, the silence. Now this is weird because I can’t hear much anyways and I hadn’t been aware of the night being noisy. But standing on the deck a in this total darkness, the silence was almost Biblical and immediately, I thought if we had our wits about us we would declare two hours of total darkness straddling midnight on Christmas Eve. A sort of “the Day the Earth Stood Still” in miniature.  Then maybe people would experience the universe as did the shepherds who “watched their flocks by night.” It is truly wonder full and awesome.

Well – those were first impressions. To the naked eye everything looked brighter, plain and simple, but the truth is there was still a lot of water vapor in the air and once my eyes had dark adapted I found I couldn’t get much below magnitude 5 which is where I get on any good night without a moon. But that was enough. And as a bonus it was an incredibly balmy 53 degrees! Quite a contrast from my last outing which was cut short because this old body just doesn’t handle 18-degree temperatures very well for very long.

At the moment I was operating on a photon deficit and needed to gulp down some of those ancient wanderers. But first I wanted to continue my tests of binoculars and this business of exit pupil and how it relates to astigmatism. So after checking Mizar to see if I could detect the double – I couldn’t – with the 10X30s I went in and got my observing chair and the 15X70s which I had stopped down to about 40mm to give them a smaller exit pupil. (The smaller the exit pupil, the less a problem astigmatism is. See this post for more info.)

Could I split  Mizar with them? No. Not even with them on the parallelogram mount.  Frustrating. I went in and got the 20X60s and tried Mizar again – maybe the seeing was really bad. Nope. I got a split.  But here’s the thing. If I want a real nice split I have to back off as much as an inch away from the eyepieces and hold my head  at a funny angle and all of a sudden stuff settles down and I can clearly see two stars where there was only a single, flaring, dancer before.  Hmmmm… I got to try  the 15X70s again. And I did. And the result was inconclusive. And then I removed the  stops so they were truely 15X70s once more and darned  – I was suddenly able to get the split I sought. Not quite as nice as in the 20X60s, but it was clearly there.

So on a whim  I went over to Cor Caroli – the Heart of Charles. This is a favorite but I could not remember the PA, nor did I know how much separation there was. Was it possible to split it with binoculars? I did remember it to be a very easy double in a scope. Wow! There was this little violet dot, clearly separated by the 15X70s. I noted the PA as roughly southwest. Then I went in and quickly checked. Here are the facts from our Star Splitters blog:

Magnitudes: 2.9, 5.5   Separation: 19″   Poaition Angle: 229°

Now that’s what I would call a perfect binocular double!  That 2.6 magnitudes difference in brightness makes it a bit challenging, but the separation of 19″ makes it easier than Mizar.  The facts for Mizar are:

Magnitudes:   2.2 ,  3.9  Separation: 14.3″  Position Angle:    153°

I think what makes Mizar a bit harder for me is not only the fact that the separation is less, but the brightness of the primary. At 2.2 it simply is more likely to dance for me, rather than settle down.  In any event, I found Cor Caroli easier this morning.

The position of my head is different with the 15X70s than with the 20X60s. If they were both the same I would assume the problem is with my eyes,  But with the 20X60s I seem to have to get above what I would consider the optical axis and  with the 15X70s I’m closer to right on, or a little below.  Go figure.

So what conclusion can I draw from all this? That there’s a knack to getting the most out of binoculars as double star instruments.  You need patience and you have to keep trying. As time went on it all seemed to get easier for me and I don’t think it was because the seeing was improving – actually it was going down hill.

But long before it did, I did a quick galaxy survey, first with the 10X30s, then with the 15X70s. My first stop was M81/82.  For years finding this pair has always been a headache for me – but with my new system of clearly identified guide posts I found them instantly – well, M81 instantly – it took a little while for the image to settle down and M82 pop into view.  I had no trouble with my other two tests as well – M51, the Whirlpool, and M65/66 in the hook of the “J” in Leo.

I then retraced this ground with the 15X70 Celestrons and was reminded how this cheap – I got them for $45 used – pair of big binoculars can do a wonderful job on locating deep sky objects. With them there was no wiating for M82 to pop in view – both of these galaxies were instantly obvious – and so it was with M51 and 65/66.

Time to get a scope out on the deck and give the cheapy ($170) Orion binoviewers another work out.  I choose the Televue 85 because it was already on the LXD55 mount and was closest to the door. But when I put the binoviewer in I couldn’t reach focus. Darn. Forgot that it will not focus in that scope with the 2-inch diagonal. It only reaches focus with a 1.25-inch diagonal. So back to the house – and into the light – to find a proper diagonal.

Once I had that in place I had no trouble with the binoviewers, but the battery on the  red dot finder was dead. I wasn’t about to change it. I just did my best to point the scope at Algieba (Gamma Leonis) and see what this favorite double was doing tonight. Found it right away too!  I was using 25mm Orion Sirius Plossls in the binoviewer – but these were acting like 12.5mm ones since the only way I could reach focus was with the “nosepiece” that comes with the binoviewer and doubles the power – in this case bringing it to 48X and thus about a one degree fov.

It wasn’t splitting at that point, so I switched to the pair of 13mm Plossls that had just winged their way here – par avion – from Canada.  These were untested Televue eyepieces from the 1980s – Circle NJ.  One had trouble being seated in the binoviewer, but I finally managed to press it into place – later I would have a heck of time getting it out. But right now the sight was simply beautiful.  there was Algieba showing just a hint of tint – orange for the primary and greenish for the secondary. Love it!

And I hadn’t even turned on the drive. Oh there was some fooling around with interpupilary distance and some adjusting to get both eyepieces  sharply focused. A bit of a  bother, but worth it. Then I flipped the switch, skipped all that annoying stuff about date and time and went straight to “targets astronomical” – pressed “enter” and I was in business. the drive grabbed immediately. Of course I could have done a better job of aligning with the North Star, but I hadn’t so I needed to make an occasional adjustment in declination, but mostly this was time to be rapt in awe and I thoroughly enjoyed it.  This is really the most fun I’ve had observing in ages. This two-eye business takes some getting used to and a little more hassle, but it’s worth it.

I can’t explain it entirely, but it gives me a much more of a sense of being there than the ultra-expensive , ultra widefield “space walk” eyepices do. Maybe it’s simply that this is natural – blending two images is what our brains are used to doing.

In any event, I finally tore myself away from  Algieba long enough to get a good look at  M65/66 this way – this time using the 20mm Plossls.  Once more a big wow! Once more, two eyes are better than one.

Yes, the binoviewer diminishes the light gathered by the scope, but not enough to matter to me.And here I had a galaxy for each eye and photons that had been travelling for 35 million years. This is what it’s all about. Can’t wait for the new, more sophisticated binoviewing equipment to arrive. Yeah – I’ve been on an Astromart tear lately selling all sorts of things so I could buy all sorts of new things. More on that in another post.

Oh – and the lights did come on. In fact, in a three hour observing session I only had about half an hour of total darkness. But hey – usually when we have a power outage we’re in the middle of a storm. This was a rare opportunity. Clear skies. warm air – and complete darkness. Delight full!

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Oh boy! Been having a discussion on Cloudy Nights about astigmatism, etc. and the last post.  What was bothering me was, among other things, how to separate the impact of power increase from the impact of exit pupil change.

See, in my last experiment, detailed here, what I did was take a 50mm objective and repeatedly change the power.  This resulted in  a smaller exit pupil – good for negating the impact of astigmatism in my eyes – but also a higher power which, of course, makes it easier to split doubles. So the experiment is interesting, but inconclusive. Someone on Cloudy Nights suggested that what I needed to change, of course, was the aperture – not the eyepiece. Keeping the eyepiece – and thus the power – the same, and cutting down the aperture would give me a shrinking exit pupil and a better guide – at least with bright stars – as to the impact of the smaller exit pupil.

So off I went immediately to make a 40mm mask for the 20X60 Pentax binoculars – which I did and the skies cooperated by giving me a cloudless early evening – something that wasn’t predicted, but I was delighted to take.

I used the masked 20X60 Pentax  as is and stopped down to 40mm, first on Albireo, then the Pleiades, Jupiter, M34, and the Rams Eyes. Very interesting – and I’m a happy camper because at last I’m seeing pinpoint stars with binoculars! (You can’t imagine how many excellent pair of binoculars I’ve owned and sold because they did not deliver this – and they all had fairly large (4-5mm) exit pupils!) But there are still a combination of factors involved, the most important one being the relatively small exit pupil which seems to overcome my astigmatism and the second most important, finding the correct head position. I did play some with IPD, but couldn’t see that as an issue.

The most surprising situation came after spending about 20 minutes trying to get a really good view of Albireo. That wasn’t a matter of splitting it, but one of trying to come up with clean, refractor-like stars – bright, round little bullet holes in the night sky – and in this case, showing lots of color.

As I settled on Albireo I kept fooling with head position – the binos were on a p-mount, of course – and focus and just couldn’t get the primary to settle down completely. Then suddenly I accidentally moved the image off center – about half way to the top of the field, and bingo! There were my two perfect stars, bright orange (not gold, as I usually see it) and blue.

This blew my mind and I kept repeating it – bringing the image back to the middle of the field where there was still significant flare on the primary, then moving it up and when I did so, having it clear. I can’t explain this. I don’t think it had anything to do with the binocular. I think it had something to do with my head position. When I moved everything around and went after the stuff in the east later I could not repeat this in any form – in fact, as time went on I was getting good crisp stars throughout the field of view, so it just didn’t matter.

Could it be the binocular cooling down? I doubt that very much for I had left it out for at least an hour before going out to observe.

The stopping down produced obvious and predictable results in all the tests. I got a little less light, but I got sharper star images with it stopped down to 40mm and thus yielding a 2mm exit pupil. I did try 15X70 glasses as a test case and while I could split Albireo with them, the split was very, very sloppy and there was no way I could get it to even remotely look like what I was seeing in the 20X60/40.

Binocular doubles in the Pleiades - modified from SkySafri screen shot.

The Pleiades provided a terrific experience. I’m planning a post on binocular doubles in the Pleiades for the double star blog I share with John Nanson, so I was real pleased to go over several doubles, some of which I had split before – they’re ridiculously easy – and some of which I had never split with binoculars. One thing that revealed itself nicely is that triangle near Alcyone towards the center of the cluster. (See the inset in the above image.) It’s easy enough to get the 6th mag star there, but the other two are fainter and I hadn’t seen them before because of the glare from Alcyone. I could just detect them with the 60mm stopped to 40mm and could see them clearly when using it unmasked. This was the clearest indicator of how much light I was losing by going from 60 to 40mm objective.

But most satisfying was the whole cluster of sharp stars.

Jupiter was certainly better when I stopped down to 40mm. That way I could just pick out Europa which had recently transited and was still quite close to the planet. Ganymede and Callisto were obvious and Io was in eclipse.

Being in the neighborhood I decided to give the Ram’s Eyes a try. There the split is 7.5-seconds and I just couldn’t do it, though with the 40mm masks on I did have a distinctive figure eight that was oriented in the correct north/south direction. Maybe with more practice and a better night . . .

With M36 I could pick up two or three of the pairs that make the body of what I think of as a Klingon War Cruiser.

Bottom line – many thanks to Ed Zarenski for telling me about astigmatism and exit pupil and others here on CN who joined the discussion and have helped me work through this to the point where I can now enjoy binocular astronomy a lot more. It’s good to see sharp stars and it’s good to have some rationale for why low power views have never worked well for me with binoculars or telescopes.

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Ok, Mars in the binoviewers just blew me away this morning – not to mention Saturn.  I just could not get over the impression of Mars as the eyeball of a gargoyle – an impression that seemed enhanced by the binoviewer’s  faux-3D effect.

But that all came after I did some serious experimenting to try to pin down this business of exit pupil and the apparent astimatism in my eyes. Essentially, exit pupil is the diameter of the cone of light that leaves the eyepiece and enters your eye. I have always been conscious of it in terms of low power in that if it is too large, you’re just wasting the light from your telescope or binoculars. Thus, for example, the typical 7X50 binoculars which are great for daytime use where gathering a lot of light doesn’t matter – are producing a 7mm exit pupil.  For most of us, as we get older our eye just don’t open that wide – 5mm is more the norm.  So that means you may be wasting half the light the binoculars gather – something that is very important for night-time astronomy viewing.

But now I discover from Ed Zarenski – and various astronomy texts I had ignored – that even a moderate exit pupil of 4mm will make it impossible for you to bring bright stars to a sharp focus IF you have astigmatism.  And since I can’t get bright stars to come to a sharp focus in any binocular of any quality that I have ever used, I began to suspect I have astigmatism. And when I did a modest, self-administered test, it does indeed appear that I have it.

50mm Sparow Haek on LXD55 mount.

So I decided to attempt to confirm this from another direction – using a small scope at  various powers to see how small the exit pupil has to be for my astigmatism not to matter. Exit pupil can be calculated by dividing the power of  an eyepiece into the objective diameter of the telescope. In this case I choose a 50mm telescope that happened to be very “fast” – F4 – so it was very much like half a binocular.

I then systematically increased the power by changing eyepieces while the scope was pointed at Mizar, a bright star with a reasonably bright companion separated by 14 arc seconds – something even small binoculars should be able to handle.  But I have never been able to split Mizar with binoculars in the past.

Bottom line – I’m loving using two eyes, but I’m also learning that the only way I’ll see sharp stars with binoculars is to lower the exit pupil, or use glasses that correct for my astigmatism.

I found that with steady skies and Mizar nearly over head I could get a wonderful split – nice and clean – with the 20X60 Pentax I had just bought at Ed’s suggestion.  IF I was very careful about my head position. Not having my head correctly aligned and held steady, the image deteriorates. But this was very encouraging. The exit pupil on these was 3mm – quite small. The image wasn’t perfect, but darned good. Much better than anything I had seen before when using binoculars that gave as much magnification, but also a larger exit pupil – such as the popular 20X80 binoculars.

That’s when I brought out the  50mm F4 refractor, so very much akin to a binocular. I mounted it on the LXD55 (way overkill, but it was handy) and aimed it at Mizar.

I started with a 32mm Plossl. That creates a ridiculously large  7.8mm exit pupil – way wider than my pupil can open, so light is lost – but the fov is wide making it easy to find things. In any event, with a nearly full Moon in the west I could not even see the third star that forms a triangle with Mizar and Alcor. But I at least found the target. No prayer of splitting it, though.

Switching to a 20mm Plossl – 10X – and a 4mm exit pupil and I could not see a split. But from there it  got better as I increased the power. A 17mm gave me 12X,  and a 4.2mm exit pupil and I felt I could see a split, but it was very sloppy with lots of light spikes flaring off the primary and ghostly double images interfering with the view.

A 12mm Ortho gave me my first really good split. This was 16.6X and yielded a 3.1mm exit pupil – very similar to the 20X60 binoculars, so a 3mm exit pupil seems to be the starting point at where my  astigmatism is not as much of a bother.

But the view continued to get better with each increase in power and subsequent diminishing of exit pupil – the 10 was real nice – 20X and a 2.5 exit pupil. With a 7.5mm Plossl I had “refractor like” images – that is the kind I would expect with a long focal ratio refractor – an F12 or F15.  That yielded 26X and 1.8mm exit pupil – so down below 2mm is real good.

And the best images came with a 6mm ortho – 33x and a 1.5mm exit pupil. This gave the kind of performance I expect out of a real nice refractor when skies are steady, as these were.

So where does that  leave me? Well, the binoviewers are no issue at the powers I’m using. For example, on the 8-inch SCT (200mm) I’m using a minimum of 100X and that’s a 2mm exit pupil – so that explains why the binoviewer images are sharp.  Interestingly, though, if I could obtain lower powers I would increase the exit pupil and could run into problems.

Of course, I can get corrective glasses, but wearing glasses while observing is a pain, so if I can avoid that, I would prefer to – and by carefully choosing what I view with I may be able to avoid it. For example, the 18X50 IS Canons would give me an exit pupil of 2.7mm and probably result in a pretty satisfactory image – about like the 20X60 Pentax. But a better choice for me might be the 70mm right angle binoculars that Garrett Optical offers. I could put 13mm eyepieces in those and get a 2mm exit pupil at about 34X. If those are Naglers, then my field of view would be about 2.4 degrees – very respectable. What this boils down to is the 10X30IS are real nice for wide fields. The 20X60 ae great for a lot of binocular double star work. I could get nice, wide field, low power views with the  Garrett 70mm and Nagler eyepieces.  And from there the binoviewers would take over.  In other words, i can see a way to always use two eyes.

20X60 Pentax binoculars mounted on a Parallelogram mount are a good fit for me now.

But, I want to move into this slowly.  So I’ll first continue to experiment and use the Orion binoviewers with  the eyepieces I have. But I am finding it is simply hard to tear myself  away from the binocular view and when I returned to the 20X60 binoculars I discovered how critical head position was, for I could get near perfect images with those as well – if I held my head just right.

This was easiest to do if I actually was a little farther away from the eyepieces than the extended eyecups called for. Going down to the observatory, I put the scope on Mars – keeping in mind that I was in twilight by now, as well as fighting a nearly full Moon. And Mars – small as it is – was spectacular in the binoviewers – I went to two hundred power and feasted on a cosmic eyeball – a ghoulish cosmic eyeball  with orange and greens in it, but the startling white polar cap appearing to distort it and give it the eyeball feeling Saturn was high in the trees to the south, pretending to be one of the Heavenly Twins , paired up with Spica. I had to do a double take when I first saw them, for I knew Gemini was not in that section of sky. The two-eyed view was  simply mesmerizing. For the first time in along time I really wanted to just sit there – not change anything.

bottom line – this was a very enjoyable and productive morning. And yes, I need to explore this business of head position more, and I need to get tot he eye doctor .

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Ok, I’ll eat my words.

When was it? Last week, perhaps, or the week before? That I tried binoviewing once more and swore that would be my last trip down that road?

See, I have ventured into binoviewing a total of five times now over several years. My most successful experience was with an early Denkmeir and they worked best for me on the 8-inch SCT I had at the time. That was about six or seven years ago. I’m not sure why I stopped using them. Perhaps just too much of a bother to change powers – and they were rather big and awkward and subject to getting knocked about.

Since then I’ve tried the closely related Earthwins and had to return them because – as with the Denks –  found them too large, and awkward, and complicated to use – especially for the kind of public outreach I was doing then. You can’t have people line up for a view and then spend half the  time adjusting the binoviewers for each person. Too bad, because the view can be absolutely stupendous as I found last night when I approached a new, inexpensive pair with an entirely different attitude.

Yes, your approach and expectations matter. In this case I made up my mind that I would treat the binoviewers as if they were a pair of binoculars with fixed eyepieces and that’s all I would use for that observing session. That’s much different  than  the mind-set you have when viewing in cyclops mode and frequently popping in one eyepiece or another with little to do but make a slight focus adjustment.  That approach can’t be taken with binoviewers where they can:

  • radically change the scope balance on a mount
  • the interpupillary distance may need to be changed
  • the focus will change considerably – I mean considerably – from a single eyepiece to a binoviewer
  • the changing focus can mean with a SCT  enough image shift to actually lose sight of your target, or at least require recentering
  • the individual eyepieces may need to be adjusted so they show they both are in focus
  • and, depending on design, you may have to pull the binoviewer out of the diagonal and screw on a barlow lens just to get them to come to focus in a refractor – hey, in my case I also had to change from  a 2-inch diagonal to a 1.25-inch one

Bottom line, that’s a lot of screwing around. Denk, Earthwin – and perhaps others – get around some of these issues by adding lenses that slide in and out in a patented mechanism, thus giving you two or three different powers with minimum hassle – but also adding bulk and weight to the whole set up.

So, my solution? First, i changed my mind set and expectations and it turned out to be a real lesson in how expectations relate to perceived outcomes.  As i say, i decided to treat the binoviewer/scope combination as if it were a fixed-power binocular – with the bonus that with some hassle I really could change powers, but it would be more involved than with a single eyepiece and I shouldn’t do it casually.  This mindset actually complements my observing philosophy where I think too often that I tend to flit around too much and not stay on target long enough.

Second, I bought – new for $179 – a pair of the Chinese imports from Orion – simple, light weight binoviewers, and as it turns out, quite effective in terms of my lower expectations. In these I settled on a pair of 20mm TV Plossls and I decided to use them primarily in the observatory with an 8-inch Meade SCT – a typical alt-az “go to” set up where most of the time I ignore the “go to” part, but take advantage of the tracking. Tracking also encourages time on target and makes using the binoviewer less stressful.

And I loved my initial experience despite really crappy conditions – a nearly full Moon, way too much dew, and high clouds frequently interfering, not to mention abysmal seeing.

The detail on Jupiter was terrific even through a dew-covered corrector plate. The Great Red Spot just jumped out at me – despite the moon being right next door.  And I know it’s just our mind playing tricks on us, but damn, Jupiter looked like a sphere rather than a disc! And the Moon? Hey, it was like taking a helicopter ride over a landscape that was fascinating even though mostly flatly lit. Almach, a favorite double, was pretty darned good as well – and I was transfigured by my view of what I regard as a Klingon Warship – the brighter stars of the open cluster M34.  That cluster has a fascinating set of pairs as well and even though the Moon was washing it out and the binoviewers stealing some of the light the 8-inch mirror was gulping down, I was transfixed. I even liked the view of M31/32, but by this time I was struggling with clouds and quickly gave  up trying to spot M110 in the moonlight and mist – and yes, I did put the 2X nosepiece on and it did give a nice view of Jupiter and the Moon, but I need  more time with it.

So I came in, jotted some notes, then decided there were enough sucker holes to give this thing a try on the TV85 – at least find out if it would come to focus. So I put the LXD75 on the deck, didn’t bother with a battery – just slapped the TV85 on and pointed it manually at the Moon – big blob. Uh huh.  Put on the 2X Barlow – and Orion does warn you that you may need this to reach focus in a refractor. Nope – didn’t do the trick. So I took out the 2-inch diagonal, put in a 1.25-inch diagonal and tried again. This time I could reach focus as long as I used the 2X Barlow. Eh – not bad, but I would have to have real good reason to change things around that much. Binoviewing is nice, but for now I think I;’ll consider that the TV 85 is a clyclops scope – and I really don’t want to try the binoviewer on anything smaller both because  of light loss and weight.

The Orion isn’t the weight of the Denk, but it’s not light. The Denk in the old Big Easy package I had most recently used – no special switches or anything – weights 20 ounces. The Orion is an ounce or two lighter. But add the switching mechanism to the Denk and it really bulks up and the price is much more.  I guess price was a major factor here. I could accept the idea of the binoviewer/scope as a fixed-power binocular at the $170 price of the Orion – not at the $500 price of the Denk Big Easy.

Truth is, the Orion binoviewer, even with an extra Plossl eyepiece counted in is roughly the equivalent of one my Naglers on the used market – so this is a binoviewer I can treat as another eyepiece. Again – frame of mind – it means a lot. 😉

Anyway, somewhere I had read – I think it was in the Denk literature – that you shouldn’t use the binoviewer with a focal reducer on the SCT. Hmmm. I wanted to give the  C6 SCT a turn with the binoviewer through the next sucker hole and there was a focal reducer on it. Certainly would give me a wider field and make finding things easier. Hell – I left it on. And guess what – no obvious problems. I need to investigate this more, but my first impression was” “I love it.” There was the Moon again, looking like a 3D globe with some space around it – 47X in a six inch by my calculations. Now that’s a nice step up from my 20X60 binoculars. Yeah! Lot’s of possibilities there.

I went back in, put up a “wanted” ad for a pair of 15mm TV Plossls and quickly ended up with an offer for some 13mm of the old  Circle “NJ” type. I like those, so I bought them. I also think the 13mm a better choice in terms of powers with the  C6  or the eight inch than the 15mm. SO given the   focal reducer, this is what the two sets of eyepieces – 20 and 13mm Plossls, plus 2X Barlow – wo;; offer me.

In the 8-inch I will then have 100X, 154X, 200X and a mostly unusable 308X – on the C6 with focal reducer the range will be more reasonable:

47X, 73X, 94X, and 146X

Take out the focal reducer and the C6 goes from 75X, 115X, 150X, and 230X – not too shabby.

But, of course, I need to return to my mindset of fixed binocular. Switching this stuff around won’t be that easy. In fact, the only relatively east   switch will be to just change to the Barlow. See, changing the eyepieces means refocusing each eyepiece individually. Something that goes smoothly enough, but. . .. well, I need experience with the system with both sets of eyepieces and I won’t have that second set for about a week. It’s on its way now from Canada.  Then , given the price, maybe I should get another Orion and put the 13mm eyepieces in it, then treat the two binoviewer as if they were individual eyepieces, putting one or the other in the diagonal. Don’t laugh.  If the convenience factor is important enough and I continue to really enjoy binoviewing – and I do like using both eyes – afterall, it’s what most people are born with, so . . . stay tuned.

Oh, and about those new binoculars . .. .

Yeah, there was more going on than binoviewing this evening. I was also putting Ed Zarenski’s advice to the test and finding out that I probably do have some astigmatism and this is what has frustrated me with low power binocular use – especially when trying to split doubles.

The binoviewers arrived yesterday just a few hours after UPS delivered a new pair of Pentax 20X60 binoculars. I put them on the P-mount and in darkening twilight – and a whole lot of moonlight – was able to see all four moons of Jupiter with ease. With the 1030IS I could see three moons – two were close enough together to blend as one. OK – that’s inconclusive. I was also able to split Albireo. That was more encouraging, though it was hard to judge because seeing was so poor.

But later the trees moved enough to give me a quick shot in yet another sucker hole at Mintaka. With the 10X30s I could detect the secondary – with the 20X60 mounted I could see it just as plain as could be.  That’s encouraging. But the important note here is that I have tried repeatedly to see Mintaka with the 15X70s mounted and can’t. Now that might relate to objective quality, but I suspect what it relates to is exit pupil and an undiagnosed problem I think I have with astigmatism. The 15X70s have an exit pupil o f 4.6mm. The larger the exit pupil, as Ed pointed out, the more problem you will have if astigmatism is an issue.  The exit pupil with the 10X30s and 20X60s is the same – 3mm. And with both those binos the primary settles down enough to allow me to see the secondary. The extra power and light grasp of the 20X60s just makes it easier than with the 10X30IS.

Don’t get me wrong. I still love IS and I still want the Canon 18X50IS at some point. The exit pupil would be even smaller – BUT, their cost is prohibitive right now. Maybe after  I sell a few more things 😉

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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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