John

I suppose that is the challenge. Imaging centered sessions might be of limited interest to observational astronomers and observation centered sessions may well not attract the imagers. Would mixed content sessions work - something for all ? I reckon imaging is the dominant sector of amateur astronomy and probably this forum currently, in which case I can understand why topics relating to that will be the mainstay of these sessions. Perhaps "Stargazers Lounge" needs to be re-titled ?

I got 8 craterlets last night. The "big four" and the "little four". My best is 11 with this scope. Useful guide to them here: https://www.cloudynights.com/topic/34841-guide-to-plato-craterlets/

Very good report and comparison Steve

I know I can only go so far in terms of detail when taking snap shots of the moon with my old mobile phone at the eyepiece of my scope and I reckon I've more or less reached the limit here. I wanted to try and capture the Hadley Rille and the Apollo 15 landing site that was showing so crisply though the eyepiece of my 12 inch dob. This is the best that I could do. I've put an old NASA map extract of the landing site area next to it with the point at which the Lunar Module landed marked with a red arrow on each image. Considering this was taken at about 400x magnification with an undriven dob and a cheap camera bracket I'm actually quite pleased with it. The eyepiece view was a lot crisper than this - probably one of the best views of this area of the lunar surface that I've had for a while. For scale, the crater that sits on the Rille below the landing site (in the pictures) is Hadley C with a diameter of 6km. I guess I'll need to upgrade the mobile phone if I want to do better !

Just a quick post to mark the superb seeing on the moon this evening. Plato craterlets, Vallis Alpes central rille, Catena Davy craterlet chain, it's all up there and steady at 300x - 400x with the 12 inch dob right now

You can't compare them - totally different strengths and weaknesses. If DSO's are more interesting then a larger dobsonian is both much less expensive than your budget and will do the job better on DSO's and will do a decent job on the moon and planets as well.

I've owned the Mk III and Mk II Hyperion zooms. Not used the barlow though. They are probably one of the best zooms around unless you pay big bucks for something like the Leica ASPH zoom. Pretty close to the optical quality of fixed focal length eyepieces such as the BST Starguider, Hyperion non-zooms, Celestron X-Cell LX's etc. The instantly variable focal length is very useful. The true field is a bit narrow at the 24mm end so I would want a wide field 26mm - 30mm eyepiece to go with it.

Good for deep sky but not so good for planetary use due to CA. But I sure you realise that given the advice that has been provided Also heavy as Stu says. I think you need to think things through more carefully. You seem to be all over the place with your choices at the moment ?

I agree very much with the above post. A 6mm and a 5mm, without a barlow would be useful eyepieces to have but the very high magnifications just won't deliver. With the barlow lens, your zoom should be more than enough. If I was going to add an eyepiece it would be at the other end - perhaps a good quality 26mm - 30mm wide field to offset the zooms rather narrow angle of view at the 24mm end ?

It is a popular focal ratio (F/7.5) with an ED 80mm scope because it's suitable for imaging as well as visual. You do realise that your 150mm newtonian will out perform such a scope on practically everything though ? An 80mm ED is a nice "grab and go" alternative though.

Still pretty light here but the scope is in action on the Moon anyway The 5mm Pentax XW gives 318x with this scope and really, really sharp views this evening

Anyone remember reviews which commented on scopes that "snapped to sharp focus" ?. I suspect the reason was that the scope was fast so the depth of sharp focus was shallow.

It looks more Questar than Meade now. That is a compliment

I'd be amazed if todays manufacturers could not produce very good quality small aperture long focal length achromatic doublets. If these are anything other than extremely good performers, something has gone rather awry.

I would need a few - it seems to be more or less permanent these days

I saw Saturn and Jupiter visually at around 3:00 am a few nights ago. They are still very, very low down from here Having observed them often over the years when they were high in the sky I'm having trouble getting motivated to get a scope setup because the views are likely to be not as satisfying If you have not seen them before I can understand why it is worth making the effort though

Another good but older (out of production) refractor is the Vixen 102mm F/9.8 achromat. Japanese made and fine optics often for quite a low price if you can find one on the used market.

There is the confusion, right there ! Can both assertions be correct ??????

When I was a kid and sci-fi / space mad, I painted the walls of my bedroom and most of the furniture matt black and then painted star fields all over them. To the brighter stars I added a set of diffraction spikes even though at that age I had never looked through a telescope. I just thought that was how stars were supposed to look ! When I moved out my Dad complained that re-decorating that room was the hardest DIY job that they had ever done All so that I could listen to Hawkwind more "immersively"

Well I am confused now Probably was before as well, so no change there

These crazy refractor people ! You can't rely on what they say of course - they are smitten after all Of course I have not fallen into their trap - I only have 5 refractors ........

Do refractor / SCT / mak imagers use processing to add in those spikes to their images do you think ?

Thanks for the answers to my question. My assumption about airy disk sizes did assume that the magnification used was consistent. I ought to have said that. I also thought (probably incorrectly) that the reason that a larger aperture scope can potentially (important P word) resolve closer pairs of stars than a smaller aperture one was because the airy disk in the larger aperture was smaller ? I didn't realise that focal ratio affected the airy disk size. I can test this I suppose by setting up my 102mm F/6.5 and my F/9 100mm refractors, using them at the same magnifications and seeing if I can see differences in the airy disk size

Aperture and dark skies are the best tools for observing DSO's. The planets and double stars are more the refractor strong points. The newtonian can do those as well though but the crispness of a refractor image is particularly nice for splitting double stars.

With the aperture the same, the airy disk should be the same apparent diameter in both scopes. Have I got that right ? So if the F/7.5 has a similar figuring accuracy to the F/15 and care is taken to achieve accurate focus, I would have thought that the actual resolving power would be pretty much the same ? Or are other factors at work here ?