Now that everything has been straightened out with the binoviewer I finally got around to turning it on to Jupiter. I spent a little time earlier in the evening with Saturn, and it was immediately clear that the night was not going to be as good as last Thursday. The planet swam in the field, and I wasn’t able to bring in the Powermate 5x and the binoviewer 1.6x together – the field was just too unstable. I backed off to the 5x by itself and the view was adequate, but Cassini’s division was not visible with any certainty, and there was little hint of structure in the rings. The shadow of the planet upon the rings was clear, as was the shadow of the rings upon the planet. Banding was visible on the planet but was not particularly strong. No moons other than Titan were visible, but it’s possible they were in the field but too dim, or too far away from the planet to be obvious satellites. I find it difficult to recognise Saturn’s moons without a guide – the inclination of the orbital plane is such that the moons are fairly spread out in the sky around Saturn, so unless you have been following them over a few days you need assistance to pick them out.

On to Jupiter. The moons here are immediately clear, at least for the four Galilean satellites. They were plainly visible and easy to pick out. The planet was less clear – two cloud belts were obvious, and there were indications of others in both the northern and southern hemispheres, but no structure could be seen, just lines across the body of the planet. Going in deep with the 5x Powermate gave no better views – I wasn’t able to achieve a pin-point focus. At the limit of perception it was possible to make out a faint star close to the planet, and Starry Night showed it as HIP73032, a ninth-magnitude star. The fact that this was barely visible in a 110-mm scope is an indication of the sky condition (hint:it ain’t good). For the record, the sky brightness reading was 17.79, which corresponds to a Bortle Class 8 sky (“City Sky”).

To close the night off – workday tomorrow – I returned to Saturn and was immediately struck by how small the planet looks in comparison with Jupiter. This time around the Cassini division in the rings was occasionally visible, so there was some improvement in seeing over the course of the evening.

It was difficult to express the anger and frustration I felt on Saturday night. I returned the William Optics binoviewer with missing set screws to Khan Scope Centre on Saturday. In exchange I received another binoviewer with a slightly different finish – still William Optics, but white instead of beige. I returned home as a happy camper. On Saturday I tried to set up to observe Jupiter through the binoviewer, and inserted the barrel of the binoviewer into the eyepiece adapter of the diagonal. It did not fit – just a tad too tight. It was cool outside though, and the binoviewer had been inside the house, so I reasoned that the binoviewer barrel was a little larger than normal due to the difference in temperature. I pushed a little, and the binoviewer barrel slipped a little further into the eyepiece adapter, and then stopped. It would go no further in, and worse, would come no further out. It was completely stuck, and I could use neither the binoviewer nor the diagonal. After an hour of pulling and jiggling back and forth I managed to remove the binoviewer from the adapter. The binoviewer was completely useless to me because of the misfit. To add insult to injury, all components are from William Optics.

A micrometer reading gave a diameter of 1.252 inches, while the eyepiece adapter had an inside diameter of 1.250 inches. That’s plus or minus 0.002 for each measurement, so nominally they both were within spec of each other. I suspect that the beautiful black finish applied to both the binoviewer barrel and the adapter was responsible for the misconnect. In any case, the long and short of things was that I had to trundle back to Khan’s once more and see how they felt about my second coming.

So… I trudged back to Khan’s on Monday and showed Eric the problem. We swapped out the barrel for the one on another binoviewer, so for me personally the probem was resolved, leaving Eric to contact William Optics to see about the old barrel. I tried the oversize barrel on three 1.25 adapters, two from WO and one from the Orion Express. One of the WO adapters worked, but the other failed, as did the Orion Express. All my eyepieces work on any of the adapters, so it was the binoviewer which was the odd one out.

I have to confess, though, that I’ve seen this problem before with another eyepiece, though it was also a different adapter. The solution for me was the same – exchanging the eyepiece for another whose barrel fit the adapter better, leaving the retailer with the problem of replacing the original eyepiece. So in both situations the retailer stepped up to the plate and resolved the issue, but it shouldn’t be happening in the first place. Do we need to loosen our tolerances to ensure interchangeability?

I bought a William Optics binoviewer yesterday at Khan’s, and tonight was my first opportunity to try it out (since I wound up pullng a 16 1/2 hour shift last night instead of observing). Transparency is currently in the toilet – considerable cloud cover, and the most obvious objects are the only objects – Moon, planets and first magnitude stars. However, the air is very steady, so despite the clouds Saturn is a very fine sight in the binoviewer – FLT 110 – 1.6 barlow, 20 mm Swan eyepieces which are stock with the binoviewer, and a +5 Powermate. I make it about 286x and still stable. The only difficulties are in achieving focus with the old R&P focuser – I’m still thinking about a very pricey upgrade – and the fact the binoviewer is missing setscrews for both eyepieces. I didn’t notice when I picked the binoviewer up, and Khan’s is closed on Good Friday, so I’ll have to wait for a few days before reporting this as a problem.

I did a cold boot on the mount and synch’d on Mars (unfortunately a small and dull presentation at the moment). A slew to Saturn with the high power set up put the planet just on the edge of the field – not bad for a cold start!

I’m hoping the cloud cover will thin out before big Jupe shows up in a couple of hours – there may be more to say later.

[OK, no joy - the clouds rolled in to stay shortly after 9.30, and the Clear Sky clock says there'll be no improvement 'till tomorrow. This time I did get a Sky Quality Meter reading - 16.81 while a couple of stars were still visible]