wulfrun

Sharpness would depend on the quality of the optics, correct collimation, how well cooled the scope is and the state of the atmosphere. I think you can discount the first factor at 65x but I'd think about the others. Have you checked collimation? Was the scope cooled for long enough? The last factor, atmosphere, you can do nothing about but how did it look visually? Your scope should be able to go to a 2.5mm (260x), in theory anyway, so the atmosphere is probably the limiting factor. Even so, I'd have though you'd notice if conditions were bad enough to limit you to 65x. Last night I used 70x with a smaller scope and got a sharp view. EDIT: I forgot to say sharpness also depends on not over-magnifying but as explained, that should not be a factor in this case.

Gone very hazy here now, 9pm ish but earlier it was clear enough for an hour and a half's "playtime". Came back in due to a combination of the cold, skies hazing over and a dewed-up finder making aiming at anything largely guesswork.

I think it's worth pointing out that the number of objective lenses doesn't correspond to the number of wavelengths correctly brought to focus. A doublet doesn't bring two wavelengths to correct focus and a triplet three. Worth reading up: https://en.wikipedia.org/wiki/Chromatic_aberration Can't answer your actual question though.

Visually there'd be precious little difference on the Moon. They have the same focal length so the same eyepieces would give the same magnification. The 250 would just give a slightly brighter view since it gathers 56% more light. Visually that won't appear half as bright again. If your eyes (and the conditions) permit, technically there's a higher level of detail (resolution). Photos could be taken at a slightly higher shutter speed for a given exposure using the 250.

SteveWolves' post above didn't, so who knows? I think I should ask him to bless me with clear skies though, when he said it was going to be clear - it was!

As long as you're ok with the extra bulk and weight of the 250, you probably won't regret waiting a bit for extra glass. Aperture is rarely a disadvantage as long as the weight & bulk aren't. For your budget, you could just about squeeze a decent short-focal length eyepiece or a zoom, like the OVL Hyperflex 7.2-21.5mm and still get the 250. The supplied 25mm eyepiece is OK-ish but the 10mm isn't very good, so either of the options I just mentioned would get you set for a while. Something to think about.

I passed on since it was damned cold and I didn't think I'd stand it for long enough to be worthwhile. As it happens, it was the right judgement because later on there was a distinctly heavy haze, bordering on freezing fog.

Worth a peruse of this site, certainly helped me choose a pair and the website is run by a member on here: http://www.binocularsky.com/?awc=11005_1599756095_2dd405fa6dca11102a441acfe1e04829&dcmp=afc-489797-na-na-longtail&dclid=CKHEmO-D3-sCFQrmuwgdSdYD6A

Yes, I was pleasantly surprised by the Hyperflex. I haven't had much chance to play around yet so I never got the chance to try what you suggest, although it makes good sense. I also have the SVbony 7-21mm so I want to try them head-to-head at some point, when conditions permit. Only looking at Mars, I just wound the Hyperflex up to the shortest FL & hoped. To be honest, I suspect that the LP here may be bad enough that a filter won't make a worthwhile improvement - but no doubt one day I'll try it. Fingers crossed on the forecast, we do seem to have been cursed for unduly long.

You could do with fleshing out some of the things behind wanting a scope. Such as: Do you live in a dark-sky area, where you can use it at home and not have take it anywhere (far)? Can you store it in (say) a shed or will it have to be taken out of the house each time (any stairs involved)? Are you ok with moving something heavy and bulky or not? Do you want it to find objects for you (Go-to) or are you happy to learn your way around the night sky and find things yourself (with charts/guides etc)? Any ideas what sort of things you want to see? * Worth noting that no one telescope suits all purposes or all people, compromises are probably needed. What suits me quite possibly would not suit you. * you said "stars and planets" but planets usually require higher magnification and stars (loosely speaking) don't.

Well if that doesn't jinx it... 😉

Well, I've been chomping at the bit for the last couple of weeks. Santa's left me a SW114P Virtuoso to play with and my birthday, 5 days later, saw me in posession of an ES68 20mm eyepiece to go with it. Needless to say, it's been cold, snowy, rainy and overcast ever since (and before, for that matter). However, last night there were fast-moving couds with some sizeable gaps and intervals and I was determined to have a go, no matter what. The stars looked a bit twinkly but that didn't stop me - I want to see something up there! And the moon wasn't up either, which could help as long as I don't want to see it. I managed to get a reasonable view of the Pleiades first, first time "proper" view in a scope. I'm sure everyone says it but yes, "wow" is appropriate. Unfortunately, it didn't last long as the next bank of cloud obscured it but the Orion nebula was still on show. Swung around to that and got an OK look. I think the LP here isn't helping and the conditions weren't the best, it was ok and interesting but a bit underwhelming. Also short-lived thanks to cloud but Mars was shining brightly. Popped the Hyperflex in for that and wound it up to "full-throttle". Not expecting much at 70x but it was enough to say it was a tiny, red disk and no star. A few minutes later it disappeared thanks to yet more clouds, hey ho. A visual look around at that point revealed more cloud than sky by a large margin, so I made the mistake of switching the mount off for a while to wait and see if things cleared. On switching back on a bit later, newbie mistake of not aligning it north, first. Back for a last look at the Pleiades and wondering why it won't stay in view for long - ah yes, that'll be why then - make mental note to re-align or leave it on in future. Oh well, it's looking very cloudy and not much prospect of improvement so I hauled the stuff back indoors - for me and the gear to thaw out! It was bloomin' cold out there, especially on the digits. Not exactly an exciting start but actually it was really worthwhile. Looks like the ES68 was a good choice and I was surprised that the Hyperflex did much better than I thought it might in a fast scope, especially at its longer end. Views to the edge were actually quite usable, although the ES obviously outdid it for FOV. A good starter pair of EPs I think - I forgot to take the bundled EPs out so I never got to compare. EDIT: thanks to those who advised me on the EPs a while back, I forgot to say.

The thing to remember, we're all learners in a sense, I certainly am. No-one knows it all. The difference I guess is how far away we are from "total newbie". It seems to me that all astronomers (or nearly so) have at least one pair of binoculars, so it's probably fair to say you wouldn't regret buying a pair. They're the ultimate in portability and always handy for nipping out to peek between clouds or whenever conditions or time don't merit setting up a scope. Plus you can use them for birdwatching/sports/planespotting or whatever other interests you may have. While you're waiting for your scope, there's a wealth of information to absorb in books and on websites. Also handy for the inevitable cloud-obscured conditions!

A barlow is an additional lens that goes (usually) in the focuser before putting the eyepiece in. Optically it effectively multiplies the focal length (FL) of the telescope by the factor it's sold as (2x, 3x etc). The magnification of an eyepiece is calculated as the telescope's FL divided by the eyepiece's FL. So, for a given eyepiece/telescope combination a 2x barlow will double the magnification, a 3x will triple it and so on. They come with a penalty (no free lunch) - there's a slight loss of optical quality due to the extra glass. That could be trivial or severe, depending on quality and various things - a barlow can also result in over-magnifying, for instance. Some barlows come with removable lens elements that can be screwed directly to the filter threads of an eyepiece to give a different factor - such as 1.5x when used this way and 2x when used separately in the "normal" fashion. I would suggest not rushing out to buy one until you think you need one. P.S. welcome to SGL, you'll get heaps of good advice from the friendly folk here - and remember, no question is too daft to ask.

Don't think of it as your dreams being crushed, just think of it as a challenge and think how good it'll feel when you do find things. The balcony may have a limited view but remember that as the Earth turns, it brings a constantly-changing new view in front of you. There may be things you can't get to see if there's light pollution and you may have to wait and pick your time for your chosen target for many things. However, the universe has a fascinating wealth of "stuff" to be seen by anyone with an open mind and some patience.

What Tiny Clanger said. Plus have a read of this thread. Yes it's fairly heavy going at first but it's important stuff to understand if you want to get the best from your setup:

Most people don't advise buying sets like that. You'll end up with stuff you don't want and will never use and the eyepieces probably won't be the best quality. It's usually considered better to buy individual items because you feel the need for them. I'm no expert but an EQ mounted scope on a balcony might not be the wisest choice for a beginner either, I'll leave it to others to advise more on that idea.

Sticking to a zoom, educated guess based on magnification/exit pupil says somewhere around a 7-21mm. Barlow it for times when conditions are good/exceptional. You haven't said what your budget is but there's an SVbony 7-21mm for around £45 or the OVL Hyperflex 7.2-21.5mm around £70. Both are well thought of. I'm sure others can offer other choices and the Hyperion 8-24mm has already been mentioned.

Too much magnification. In the 4SE it gives x220-x440, unlikely to be used often in the UK. Even higher for the 8SE, so even less usable.

Hi Joe, It'd be helpful if you say what telescope you are planning on using it in, what you're interested in looking at/for and how much you're willing to spend. There's quite a range to choose from.

It's fair to say they compare favourably with anything I've ever come across on t'internet. I'm assuming you're "only" an amateur but I'd easily have believed they originated from a professional outfit! I think stunning is the only appropriate word. Worth pointing out that the thread title's meaning could be construed as relating to eyesight but 20/20 vision is actually average, contrary to popular belief. These are not "average" images!

Jupiter doesn't broadcast on exactly 20.1MHz and you'll need an antenna dish pointed at it to receive radio waves from it, if you don't want to pick up everything else (mostly man-made). I'm fairly confident the answer is no, a simple SW radio won't work like that. I used to trawl the SW bands in the days when they were busier and never noticed any particular Jovian interference. Nowadays there's a lot less commercial use on SW but I still doubt it'll be so simple. There is a section on radio astronomy on here, you might get a better answer there? EDIT: according to Wikipedia, decametric Jovian radio bursts were first picked up in 1955 on 22.2MHz

I have no personal experience of that model, I'm quite a newbie myself but I've been doing the homework, like yourself. The base of a Dob doesn't have to be levelled perfectly but purely for stability you wouldn't want to be too far off. Some people put them on a wheeled base or add castors and such like. Equatorial is better for tracking things but it's a more complicated system for a beginner and a stable mount for a large reflector will be heavy and expensive. Aperture is always king, all other things being equal. Of course, the problem is all other things are never equal. Any scope involves a compromise somewhere. Hope that's helpful.

Sounds like a perfect location for a large-ish Dobsonian scope, you won't need to lug it around so the size & weight won't be a problem. Fully-manual would suit the "old-school" idea. As for eyepieces, it depends what scope and what your interests are. Pick a scope and there will be plenty of advice on offer. In regards to exit-pupil, think of it as a shaft of light exiting the eypiece and entering your eye through your pupil. If that shaft is too thin, it falls only on the very centre of your retina, making it somewhat dim. If it's too fat to fit through your eye-pupil, some is just wasted. There's a range of useful exit-pupils and as your eyes age the maximum pupil shrinks. Again, pick your scope and the sensible options can be advised. EDIT: some idea of your budget would be helpful too.

That's modern "Elf and safety" for you. In my day, the chemistry lab ceiling bore many a scar to testify that things went wrong. We cheerfully set fire to magnesium, allowed sodium or lithium to dry out and made picric acid to play with. And, of course, we put lit tapers to measuring jars of stoichiometrically-measured hydrogen and oxygen mixtures. Some of us got burns when we weren't careful enough - which quickly teaches you to pay attention. Oh and bunsen burners are far more fun when connected to the water-tap than a gas-tap.