JOC

Jupiter is very low on the horizon at the moment and you are looking through a lot of atmosphere before you get there. I would continue without the Barlow - more magnification isn't always good for Jupiter, many people find 'smaller' is often clearer and often better. Also it is not a solid rock like the moon (it is a fuzzy gaseous mass) and so will never have crisp edges as the moon does. If you get a cool, clear evening after the rain has washed out the dust from the atmosphere and the earth is bunging up loads of thermals you might find the image becomes much clearer. With the depth of field remember how much closer (in miles!) the centre of the moon is to you than the outside - it then seems reasonable that it isn't all possible to be in focus at the same time. Some EP's have less good properties at their edges than in their centres too which might not help.

I know someone whose eye surgery went wrong. The anaesethitic was injected into wrong part of the eye and she never fully recovered. I would love to have my contacts back full time, but having worn old fashioned thick contacts for too long when I grew up I now have to keep them for high days and holidays. I live in blue blooded fear of hospitals and procedures at places like the dentist. I don't like not being in control of my own outcomes. Consequently even if the success rate was 100% I doubt I would voluntarily have corrective surgery even though I loathe my specs with a passion. I wouldn't be able to sit through it. If I start to lose my vision through cataracts then I guess I might have to get my head around it.

Sound like a great trip and chapter and verse on the subject - nothing beats first hand knowledge!

You can, but I can assure you there is no value or pleasure, just absolute fear to be gained from skiing when it's that foggy you can't see your feet!!

Why not? It's no different to throwing hundreds of pounds into horse riding and just doing it for pleasure, or spending thousands doing up an antique car just for the pleasure of driving it, or spending thousands decorating a house just for the pleasure of living in attractive surroundings, or spending £xxx on golf clubs just to take a walk chasing a little white ball, or spending hundreds on bird watching kit just to see the birds, or the equivalent on any other hobby archery, fencing, skiing, rock climbing, scuba diving etc. None of it needs to make any money the enjoyment/thrill gained is seen to be worth the amount invested without any other monetary recompense. Most of them finance their hobby by having other jobs or sources of income that in many cases won't be related to astronomy at all.

This was the direction my thoughts went in - large strong tubes may present the possibility to be re-purposed into urban missile launchers - I've got a vague notion of seeing something banned in the media along these lines many, many years ago

Great thread and answers many thanks. There was me sitting on the fence this morning thinking - 'shall I post the thread - they'll laugh me off the forum for not knowing the difference'. Instead it looks an interesting subject

So we are talking about the physical shape of the mirrors - is a spherical one then as though you have sliced the edge off of a perfect sphere where as a 'parabolic' one being one with either less or more curvature than the side of a perfect sphere would have? I must admit when I peer into the back of my reflector I am not altogether aware that the mirror I look at is even curved - to the naked eye it looks, well....., flat!

I've just read a thread where a newcomer asked what to get and in the course of the discussion two different mirror types, spherical and parabolic, were mentioned without any firm indication of how they are different, why one might be preferred over the other and for what reason this might be. Yes, I could go off and 'Google' it, but it occurred to me that to run a thread might provide some information in the beginners area that might be to someone's advantage.

I must get my telescope out of the porch and have a session - there have been a couple of nights recently when conditions have looked great and I have just been too busy or tired to be bothered, but have noted both Jupiter and Venus pominent in the sky by eye. I don't know if anyone else has noticed, but on the occasions last year that I did see Jupy it is almost easier to see the details on it before it gets really dark - I think because it seems less bright against the lighter sky.

My telescope is from a similar stable, just a bit bigger and F6. I have a 8mm BST and it works well for my setup. However, strange though it may sound looking at the list of lovely EP's in signature what I have certain liking for is my 14mm Meade 4000 in my x2 SW Barlow. By rights amd in theory I have far better single EPs to use, but it just seems to work well for me, so sometimes it isn't about the best sounding EP. The other thing to remember is that Jupiter doesn't have solid edges like the moon, it isn't a 'chunk of rock' and so will never look solidly 'crisp' around the edges no matter how good the EP.

The alternative is a brother, a workshop, a lathe and chunk of aluminium from ebay for about £4 and you can miraculously become the owner of one these oversized focus knobs, isn't it smart?!:

A birthday card I recently received. Two penguins lying flat on the ice looking at a starry sky. Penguin 1: "What do those stars in the sky mean to you Eric?" Eric: "They mean someone's nicked the ruddy igloo" Ah, found the cartoon here: https://www.calendarclub.co.uk/humour/comics-and-cartoons/eric-the-penguin-easel-calendar-2018-r201682

FWIW I plumped for the 8" flextube rather than the one you are selling, having seen its ease of use and storage I'd never consider the purchase of a solid tube version if I upgraded in the future.

Well done Stu. As a relative newbie to SGL your enormous contribution is already something that I see, it takes a special wisdom to moderate an online forum. You must be an allroung good egg methinks