Binoviewing Saturn and Jupiter (19-20th August)

[Davesellars]

Last night I managed to get my binoviewers in to action with my new pair of 18mm BCOs together with a barlow effect of 3x power meant an effective eyepiece FL of 6mm and thus 119x with my 102ED. I'd put the scope out to cool and actually the temperature was dropping fairly rapidly but it was very dry with zero dew.

Saturn first at around 11pm.... I'd aligned first with the 25mm Plossls in the binoviewer and for some reason I was getting a double image with the BVs.. after reseating the plossls however this seemed to be fixed - I suspect that they are quite bit more picky with having undercuts. After ensuring this I swapped out for the 18mm BCOs and a touch of fiddling was required loosening a touch one of the eyepiece holders which then presented a perfectly merged image. The seeing was a bit iffy with the planet being so low however being able to just stand there looking into the BVs for minutes on end rather than seconds mono-viewing meant I was able to take full advantage of the brief moments when the seeing stabilised sufficiently. The brighter cream central region was very clear as was the Cassini division in the moments of stability. At 119x, the planet is still quite bright and I felt that it would be beneficial with more power applied to tease out more detail in the bright rings especially. Actually, I was actually quite surprised at how large the planet seemed for only 119x power - it seems to be an illusion from using two eyes instead of one? I spent a good hour with Saturn marvelling at the sight which only seemed to get better with time.

After a bit of a break from Saturn I waited for Jupiter to rise sufficiently and indeed at approx 00:45. My first sight of Jupiter with the BVs nearly knocked my socks off! The seeing was considerably better with the additional altitude with much longer periods of stability.

There was immediately a considerable amount of detail of the planet's surface and extended periods of time at the eyepiece I was just able to soak it all up without looking away. The GRS was just almost central in its transition, the full structure around the GRS itself was very clear with the central core of the storm showing a nice orange hue which seemed to change with the change in stability of the air - sometimes it would lose the colour altogether and other times quite a bit more intense orange. The South Equatorial belt was sharply defined by the cream/white South Tropical Zone to much lighter South Tropical Belt. Very faint markings in the surface of the SEB could be easily drawn out. The NEB was even more intense with a vivid orange/brown hue that again changed depending on the air stability. Very dark/black smudges were very distinct in the NEB belt along with a mass of shapes and lines that could again be drawn out with extended time at BV. The Northern region also showed very delicate detail of further belts and regions but this was quite indistinct around the polar region.

Ganymede then popped up from behind the planet - the satellite rising from the surface as a tiny point of light - It was quite fascinating to watch the moonrise and see it relatively quickly reach the point of separation from Jupiter itself.

Jupiter to me looked absolutely huge in the BVs with an excellent level of contrast and detail at 119x - I am not overly sure that more power would be required or beneficial - If so then it would by a light touch perhaps to around 150x.

The only issue I found later on was the eyepiece seemed to start fogging up a touch after 20 seconds with my eyes to them - The eyepieces were quite cold to the touch now. I think perhaps with the colder nights it may require the use of dew straps wrapped around to just to keep the eyepieces at slightly raised temperature to avoid this issue.

The Moon was rising now, but it would be good while until it was visible from my position so I packed up happy with BVs and their performance with the BCOs which seem to be a superb purchase.

[Knighty2112]

Nice report. Yeah, Jupiter was the best I’d seen it all year at around 00:45 after it came into view from behind my house from where I was observing in the back garden. Using my Celestron Omni 120mm ‘frac with Celestron Duo 5mm to view through Jupiter was excellent, with belts and GRS easily visible, with very steady seeing. The moons also looked like moons too rather than the normal specks of light. Best night of the year so far for me for observing.

Edited August 20, 2022 by Knighty2112

[Franklin]

Baader BCO 18mm are awesome bino eyepieces, I've got the set and the 10mm are superb as well, no need for barlow with them but I use a 1.7x GPC to get focus. The 6mm is good if the seeing allows, mainly for luna but the eye relief gets pretty tight. The 32mm BCP gives a bright low power but with a little vignetting, my binos have about 22mm clear aperture.

Saturn and Jupiter looked etched last night through my binos with a 3" refractor using the same eyepieces as you use 👍.