Zermelo

A long time ago I read an account by someone - I think it was Isaac Asimov - who as a child had gained a sudden interest in astronomy. He went to his local library and asked the librarian for "a book about the stars". He was dismayed to be given a volume about Hollywood.

Do not exceed the Chandrasockar limit

Some possible anwers: (1) Theistic design, which won't be discussed here. (2) There may be some (as yet undiscovered) underlying reason for the physical constants being what they are. (3) The Anthropic Principle, as mentioned above. (4) We're living in a simulation, or allied explanation. Our discomfort lies in the apparent unlikelihood of the realty we experience, but probabilistic reasoning about single events can be tricky. Or is "our" reality just one of many universes with varying properties? It gets metaphysical very quickly.

Now, that's provoked a thought that I won't be able to suppress until I do something about it. I'm in the habit of leaving lots of spares, like biros, tissues, pain killers and bags of loose change, in various places like car glove compartments and rucksack pockets, just in case I get caught without when I'm out. So, should I buy a spare "emergency" budget zoom eyepiece, at least for the car I would use for transporting to outreach or dark sites, on the off chance that I forget to take the eyepiece case? It's probably one of the less plausible excuses ever dreamt up.

Ah, it was you! I clicked through and it had already gone.

The further you travel to a dark site, the more likely it will be that you forgot to bring an item that will prove essential.

Loving the nuts on the accessory tray.

I started too late to catch Jupiter and Venus with the Mak, though they did look impressive naked eye. I found the seeing to be average, not as good as the jet stream forecast would have suggested. New doubles were HR 1442, 15 Mon and HD 47888, plus old favourites Beta Mon, Almach, Mesarthim, and 19 Lyn. Finished with the moon, and the mountains around Sinus Iridum were showing very well on the terminator. Promontorium Laplace at the end of the Jura Mountains was throwing a lovely shadow onto the bay.

Thanks - it's the first time I've attempted a "proper" review, but I think they can all be useful, if the reviewer is clear about their observing experience (and perhaps their physical condition! ) Yes, I think the eye relief will be a problem if you need eye glasses. Of course, with the short focal lengths of this zoom, it's likely that the exit pupil will be fairly small, so milder astigmatism may not need correction.

The number ranges also used to map onto a list of astronomical objects, of increasing spectacularity. They disappeared at some point.

I'm also going to have to give a non-definitive answer. I use goto most of the time, even now that I know the sky better. I value it because it speeds up target acquisition and maximises the observations in the available clear spells. If I lived in the Atacama, I might do more hopping. But it's only the pointing function I really need, push-to would do me as well (and I often use the mount that way now). However, I also value the tracking, in particular because I often share sessions. So overall, it makes sense to have goto+tracking.

Plenty on here for new starters. To anticipate what a small scope might show, you might also want to have a look here:

Hello, and welcome to SGL. Here are some links you might find useful: https://stargazerslounge.com/topic/365881-buying-my-daughter-her-first-telescope/ https://stargazerslounge.com/topic/365324-1st-scope-for-child/ https://stargazerslounge.com/topic/387476-first-telescope-advice-and-recommendations/ https://www.firstlightoptics.com/beginner-telescopes.html https://gostargazing.co.uk/which-telescope-is-best-for-beginners/ https://britastro.org/node/15810 https://lovethenightsky.com/best-telescope/for-kids/ https://uk.telescope.com/assets/articles/content-popups/whats-the-best-telescope-for-kids.html

I always start and finish with a few minutes just with naked eye, and wandering about the garden to see the bits that are hidden from my observing spot. But I am sometimes guilty of getting completely absorbed in the object under investigation, or in making notes, or in checking what's up next from the list. And then I'll suddenly look up and find that the sky has become marvelous while I've had my head down. Then I'll feel like the parent at the nativity play who's so busy filming it that they didn't actually experience it fully. I suppose one reason is that we get relatively few good nights in the UK, and the temptation is to make every minute count.

I would go with the Nirvanas, unless you are prepared to spend significantly more than £100 per EP. If you really like the ES 82 design, but aren't fussed about the name on the side, you can save a bit here: https://www.opticstar.com/Opticstar-Ultra-Wide-Angle-XL-Eyepieces.html

For people of a certain age, the ultimate agent's case will always be this one:

Astronomy meets Tetris.

I agree that the 10mm is superior. I've had several evenings when I've seen more detail on Jupiter in the 10mm than I have with any other EP, even if the disc is smaller. It renders subtle colours well, has great contrast and is very sharp. There will be times when you want more magnification, but if you're trying to decide between the BCO 10mm and 6mm, I'd go for the 10mm and pick up a Barlow later on.

If it's a diffuse, symmetrical and stationary glow around the planet, it's likely scattered light. Quite what's causing it isn't always easy to tell. The level of polish and quality of eyepiece coatings make a difference, and bright objects are the most challenging. If your Baader 6mm is the BCO, then my experience is that it is sharp, but gives more scatter than, for example, the 10mm BCO. I've not used TMBs, but I have read that there are several makes of the same TMB design, of varying quality. And it might not be down to the optical surfaces at all; moisture in the atmosphere can cause the same effect, as can very small amounts of dew that are not obvious. Try different eyepieces over multiple evenings and look for differences. There's some discussion here: https://www.cloudynights.com/topic/569554-reflections-ghosting-glare-scatter-eofb/

A mathematician might answer that the marble can be chopped up and reassembled so that it's just as large as the sun, with the help of an (apparently innocuous) assumption, and a very subtle knife. https://en.wikipedia.org/wiki/Banach–Tarski_paradox

Yes, my Hyperflex hasn't had much use recently, but doing the comparisons reminded me how sharp it is. As you know, the downside is that the AFOV falls off quite a bit at the long end. But still good value at £85. The BCOs are even better value, I've not used a sharper eyepiece than the 10mm.

I've never used Hyperions. There's a consensus that they're not at their best in fast scopes (below F/6), but they should work well in the Skymax. You'll get a wider field, and good build quality, coatings, etc., but they're over twice the price of the Starguiders, in the UK at least. I don't think you'll get better performance than the Starguiders at their price, and they would also perform well in a faster scope, if you decide to get one later on. If you do want to spend more to get a wider field, I'd look at the OVL Nirvanas, which are good value in their class (and there is a 10mm). From within the EU, I believe these are identical, but others may know more.

Confused. That CN thread, and Ernest's bench review, says 5 elements/3 groups, consistent with an Erfle variant. But the Bresser web page says 8 elements/5 groups, more like the UFF (9 elements/5 groups). But Bresser quote the same weight as Ernest (within a couple of grams), so is that a cut-and-paste error by Bresser?

I'd be surprised if there really were any difference in eye relief. The view on here has always been that they are just different badging of the same generic eyepieces (and I think there are others). More likely is that some of the companies have been more accurate than others in their sales literature. It's quite common.

I use a dew shield every time. Even if there's no dew, it helps to stop stray light entering the top. You can get resistive heaters that are shaped to fit specific secondary ovals, but it's not difficult to glue some ordinary resistors on the back, of an appropriate resistance and rating. As for the heat transfer, you could use some of the stuff they use for mounting heat sinks onto CPUs. It's available in small tubes.