Zermelo

https://xkcd.com/2844/

If they can do it, why can't we? https://www.space.com/chile-new-standards-fight-light-pollution

Snap. The 1.25" prism is also my only piece of Tak, and likely will remain so.

Aperture fever strikes again. It sounds like a marvellous experience, Rob. Did you see much colour in the dobs?

No, you're not:

Yes, to clarify my previous comment, I fitted a 2" visual back to my Skymax, but not a new focuser.

You might want to start a new thread. I can't remember if it was a Skymax you were talking about. If so, there will be some vignetting (dimming at the outer edge) if you use some eyepieces, though I've not noticed with mine. You might be interested in: https://stargazerslounge.com/topic/336529-sky-watcher-mak-127-visual-back/#comment-3662339 https://stargazerslounge.com/topic/356717-sw-127-mak-ota-with-2-focuser/

True, it has "only" five elements. Svbony did market the more complex 15mm and 18mm too, though I haven't seen them for sale recently.

I'm not sure if Svbony market two different zooms with almost the same range? The 7.2-21.6mm looks almost identical to the OVL Hyperflex and others (but quite a bit cheaper): But then there also seems to be a 7-21mm that looks different:

Another eyepiece for me today. The SV190 is Svbony's version of the 10mm UFF. I'd noticed the price creeping gradually downwards over recent weeks, but hadn't been tempted as I already own the Celestron version (Ultima Edge). And that one has been a bit squeezed out by my 10mm BCO and 9mm Morpheus. Then last week I saw it offered on eBay for £16 posted, and thought it might be worth a punt, to see if perhaps I could use it with the Ultima as a binoviewer pair. It even came with a frameless IR/UV cut filter, though that will go straight into the bits and bobs drawer until I think of something to do with it. And here it is with the Celestron. Only their mother could tell them apart?

I'll be interested in your findings. It's the one I need for the set, too.

An excellent writeup, what a great evening.

Well, for once the forecast held: and so I managed a short session this evening. As well as a new moon, one of my neighbours was away too 😀

Just a couple of hours with the Mak tonight. It was noticeably colder than of late, but not uncomfortable so. Transparency was good, apart from the occasional cloud. With no moon, it was about as dark as it gets here. Seeing good/average. I was still interested to see how my cheap Svbony 9-27mm zoom compared with its more expensive companions. It did well again. At 9mm, it showed the double Gamma2 Delphini crisply, though not quite as tight as the Morpheus 9mm. However, the yellow/blue contrast was noticeably more distinct in the Svbony, while scatter was the same in both. On the rather dim globular M72, I was surprised to find it, showing obviously (though faint) in the Svbony at 27mm, despite the background being light with the large exit pupil. The Morpheus at higher magnification did manage to show some granularity, which the Svbony at 9mm could not. The more accessible glob M15 showed some stars flicking in and out with both the Svbony and Morph 9mm. The view in the latter was better, though not dramatically so. Saturn showed well in a Morpheus 6.5mm, with a clear northern belt, Cassini division just visible at the extremities, and satellites Titan and Rhea. The view in the Svbony at 9mm showed good contrast, and - surprise - Tethys was also visible with averted vision. It was also seen in the 9mm Morpheus, but there was little to choose between them. Jupiter was a bit disappointing by comparison; NEB and SEB were obvious, and two further bands very faintly seen, but no real detail in any EP.

LIDL have one on sale from this weekend, as part of a space-themed offering. No idea what it's like, other than the pictures in the listing. https://www.lidl.co.uk/p/space-themed-projector/p10008138

It's already been done... https://tardis.fandom.com/wiki/Voga

I heard that article too. At the rate that AI is coming on, there's a chance of some decent nowcasts before my eyesight or joints gives out.

A few sucker holes, more than likely.

I don't gamble, but I know there are online betting sites where you can "cash out" your bet on the result of a match in advance of the final whistle. Very useful if you've bet against Man Utd at home, for example. I want the same facility implemented on Clear Outside. I usually ignore any good news that's more than 24 hours ahead, as it almost always disappears in the interim, but it would be very handy to "cash out" on my current forecast for Saturday night:

It can be difficult to get the position right, and some eyepieces are more "fussy" than others. I have failed miserably, even using one of the (cheaper) phone holders. Others have reported favourably on this version, which is more expensive but gives you fine control in three axes.

Very interesting. I felt the Svbony generally outperformed the 4mm Nirvana when I compared them across a number of sessions. I also find my 16mm Nirvana does better than the 4mm, though I know others think the reverse. Can you recall using your 16mm for comparison?

Evidently CO is telling me to take up solar ...

If you want to try one, you could consider the 10mm BCO. It performs very well for its price, and the eye relief isn't too bad (not good enough for glasses though).

That's very impressive (and expensive). When I was at school, the Farad seemed to be a hopelessly optimistic unit. 100μF was a big capacitor! Most were measured in nF, or even pF.

I have this one from childhood, it's out of print now but comes up frequently second-hand: ISBN 0 600 00893 2, published 1969 with several reprintings. It's a nicely presented small format book, but shows stars down to mag 5 only, plus selected DSOs. Good for general browsing, but much less detailed than Norton, S&T Pocket Atlas, etc.