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Well, I really thought we were doomed to watching the historic transit of Venus – last one for 105 years – on the web.

I had been ready to drive any where in the Northeast to see it, but the whole Northeast was socked in tight. I saw some hope in the few hours before it when this cloud pattern appeared.

This was the local cloud pattern about an hour before the transit was slated to start.

That gave me a slight ray of hope, but half an hour before it was to start I went outside and we were 100% overcast, so I settled down to watching the web cast from NASA, though the car was loaded with scopes for a quick trip to Gooseberry should things improve. The web cast  was slated to start at 5:45pm EDT.  I picked it up and we slowly moved towards the start of the transit a few minutes after 6. Right about  6 I decided to check on the weather satellite once more and darned if it didn’t show a hole over us – something I would have seen if I had looked out! Bren and I rushed out and I set up the TV85 and little Ha solar scope on a dual mount at the end of the driveway, unpacking it from the car. ( I had been planning to go to Gooseberry.) I hastily sent out an email telling folks I would be observing here.

And we did! Bren and I got a wonderful view right at the start of the transit and off and on for the next 45 minutes. I also had put one of the cheap solar filters I had bought for binoculars over the Rebel’s 300mm lens and I took several shots with it. What I got wasn’t anything to write home about, but hell, it was a picture and pretty much captured what we had seen. What struck us both was the size of Venus – larger than expected – the crispness of the little dot, and the blackness of it – much blacker than the array of sunspots easily visible below it.

This one was taken at 6:22:38 pm EDT using the 300mm – ISO 200, shutter speed 100 F5.6.

This second shot was taken at 6:27:13 pm EDT at ISO 200, 1/300th second and F5.6. I took many shots between these two trying different shutter speed and tweeking the focus because I could not be sure when I had a sharp image.

Karen Davis came over with Mason from next door and they both got a good look at the event.  Then some guy came by in a car, saw us, and stopped. He was using apiece of smoked glass that he seemed to have confidence in and said he could see it with the naked eye. Judy Beavan showed up as well, the only one on my email list besides Karen. And a little later another newcomer – Susan Czernicka. Susan wrote me immediately upon getting home:

I’m your excited neighbor from 1414 down the road who is feeling fortunate beyond words to have happened upon you out on the road.  I can’t thank you enough for enabling me to see the the transit.  Please add me to your email list.

So all in all, it was a nice event.  John Nanson saw it through breaks in the clouds from Oregon, and Dom and Daphne got great views – again through holes – with telescopes at the Sydney Observatory. Checked in on some of the Web coverage from time to time as well. Here’s a typical screen shot.

Meanwhile, real science was done during this transit by observing light reflected from the Moon and getting a reading on that which will help with studying extra-solar planets. Plans are being made for similar observations of the transit as seen from Jupiter and from Saturn later this year when the alignment for those planets is correct.  For details, see this article. 

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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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, , , 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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Comet McNaught is on schedule zipping past Almach, Jupiter does look a lot whiter than I remember, and Uranus is indeed close to it – that I can confirm because the skies cleared this morning and gave me a good view of these three and more from Allens Pond Wildlife Sanctuary.

Jupiter winked in and out, competing with a nearby 24-day crescent Moon, as I crossed the Rt.88 bridge near Horseneck at about 2 am. Obviously there were some clouds about still. but the skies were basically clear. The moon really was quite beautiful, but I wasn’t sure how it would impact the comet. And Jupiter seemed brilliant.  I suspect it’s actually gotten a little brighter without its south equatorial band, but I’m sure that change wasn’t detectable by me. I just haven’t seen it for many months and so it seemed especially dazzling.

When I got to the parking lot just north of East Beach the first thing I did was look for Comet McNaught (C/2009 R1) with my 12X36IS binoculars and it took me about 30 seconds to locate second magnitude Almach and the comet  northeast of it by a couple degrees, but in the same field of view. That will change, of course, as the comet makes quite good progress to the northeast over the next several days, cutting right between Mirfak and Algol by Saturday morning.  I was both pleased and disappointed with what I saw – pleased that it was so easy to see, so it’s brightness is in tune with predictions. However, disappointed in that I saw no hint of a tail.

I took a few minutes to set up the 20X80 binoculars on a p-mount and my  60mm Unitron and examined McNaught in both. My conclusion? It looks a heck of a lot like M13 does in these instruments  – right at about magnitude 6, maybe a tad brighter, and covering perhaps 10 minutes of arc with its nucleus and coma. The nucleus was either quite large – or if there’s a separate, bbright one it was beyond the instruments I was using and the seeing conditions. I could not detect McNaught with my naked eye, though the skies were incredibly transparent – and the seeing incredibly poor, aggravated by wind gusts that shook the telescope and made it feel a lot colder than the 59 degrees my car thermometer said it was. (Yes, I had on two sweat shirts and a winter jacket – still felt cold!)

Using the 60mm and a 17mmPlossl ( 53X) I compared McNaught with a triangle of 7th magnitude stars in the fov which I put out of focus to simulate the coma. It was definitely brighter. Then using the 20X80s I compared it with M31, the Andromeda Galaxy. It was much smaller and significantly dimmer.  The Moon was about 40 degree away – much closer to M31 – yet I could easily make out the outer regions of M31, but saw no signs of a comet tail. So if it has a tail – and I haven’t checked other observing reports online yet – it needs more than 80mm binoculars to show.  With the naked eye I could see all the stars in the Little Dipper easily and the summer Milky Way was fabulous, reaching down through the Teapot before diving into the ocean past the Scorpion’s tail.  In fact, the Milky Way was worth the trip in itself.

And a good thing.

Seeing was so horrible that  I could only get glimpses of the North Equatorial band on Jupiter and with the 60mm that should have been easy, even with Jupiter just 12 degrees above the horizon. I was left with a general impression of the southern half being much whiter than I remember, so I would say the south equatorial band is still missing. But the view was disappointing because of the poor seeing.

Trying to establish the magnitude of a comet is a very subjective business, but I felt in  both magnitude and size it appeared inthe 12X36IS binoculars a tad dimmer than M13 and probably not so big, but definitely brighter – and larger – than M92. But these are guestimates. Both these globulars were high in the sky and well away from the Moon, so direct comparisons were difficult. But M92 is magnitude 6.5 and M13 5.8 – or 5.3 if you accept  Stephen O’Meara’s estimate. In any event, all I would claim is that Comet McNaught is in this ball park and looks a lot like a globular. I probably should have compared it with M3. That was lower in the sky and at somewhere between 5.9-6.3 magnitude sounds just about right.

At one point the motion sensitive security spotlights for the Audubon office came on, yet even with these beaming down on the white shell parking area  and blasting my night vision, I could step behind the car, look up, and see to magnitude 5 easily. And while some cloud scudded past, theymoved quickly and I observed for at least an hour, so that wasn’t the issue.

So what’s this mean for the future? Well, tomorrow morning is supposed to be clear, so I hope to get a look at McNaught in something with more light grasp – probably an 8-inch SCT. And who knows, in a few days its going to get lower, but closer to the Sun and so it still could develop a nice tail.  S&T’s predictions were for the best view  at mid-month.  And in the final analysis, with comets we never can be sure what to expect. (For a chart showing McNaught path over the next 10 days see my post here: http://wp.me/porOR-t2)

Meanwhile, I certainluy hope for better seeing.  I did manage to check out a couple of wide doubles with the 60mm – Almach and Cor Caroli. With Cor Caroli I followed the advice in  “Turn Left at Orion.” That is, I put it in the center of the fov and then waited a couple minutes – sure enough, right on schedule here came a fainter, but nice double, Struve 1702 into the field.

Cool! That means the Earth’s still turning.  😆

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Shivered on Gooseberry with a small group of mostly new observers as the clouds gave us just enough of a gap to catch Venus, a slither of a Moon a mere 1.4 days old, and Mercury beside it shortly after sunset.

I really didn’t think this one was going to work. The CSC forecast yesterday was for clouds at sunset today. The forecast this morning was for it to be clear – but by noon  the forecast had changed back again to cloudy. At 5 pm  the satellite showed clouds moving in from the northwest, but many were drying up as they got here – but more and thicker ones were on the way.

I sent out an email to those interested advising that it really did not look promising. But I said I would be there on the off chance we got a lucky break. I really didn’t expect anyone to join me. Well, folks got the email and decided to come anyway, so there were seven of us there and as the sun ducked into a bank of clouds about 10 minutes before setting it really did not seem good. But there was some blue above the clouds and about 15 minutes after sunset Venus popped out in it – and and almost at the same time the crescent moon was easily visible in binoculars and could be picked up with your naked eye as well – but no Mercury, though it was a bit less than a degree from the Moon.

However, when I turned the 80mm refractor on the Moon, there was Mercury, right where it should be, so every one got a chance to take a look. It was a mere dot, mind you, but clearly visible. But no amount of coaxing could bring it out of the haze enough to see in binoculars, let alone with the naked eye. Eventually it was joined by Mars ( almost overhead)  and Saturn (high to the southeast), so we had four of the five naked eye planets forming a nice arc across the sky and giving everyone a good sense of where the ecliptic is.

But cold! i was really unprepared – having cautioned others to dress warmer than they thought they should, I didn’t.  There was a wicked  southeast wind down there that was cold as the dickens, so I wasn’t too disappointed when the encroaching clouds made it impractical to stay too late.  😆  Still, I counted it a minor, but fun piece of outreach. (In March we had a similar view – but much clearer skies and a Moon just 24 hours old.)

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