Highburymark

Very nice - the ultimate easy way to stargaze. 

I always use an artificial star for my testing. Pretty much all doublets at F/7.5 and faster will show CA out of focus - even those using fluorite. My FC-100DC had a clear purple ring out of focus. In focus, it was mostly CA-free, but on the brightest objects, a bit of false colour could be seen. This is perfectly normal. My TV85 is the same. I think sometimes “CA-free in focus” gives the impression that no false colour can be provoked even on the most difficult targets, when this is normal for medium fast doublets. Far more important is control of spherical aberration, in my view. If you’re only seeing tiny bits of CA at high powers, I’d ignore it and just enjoy the scope. The only star test I’ve done with no false colour in or out of focus is with a triplet, though maybe slower fluorite doublets might also fit into this category?

I’m a confirmed refractor man. Here are most of my refractors, past and present. Equinox 80ED, couple of Lunts, FC-100DC, TV85, TSA-120 and Tecnosky 60ED.

1 hour ago, DirkSteele said:

Technically I was the postman as I picked these bad boys up at AstroFest yesterday. Looking forward to trying them out.

Very nice Matthew. Similarly inspired, I picked up these two in the past week.

18 minutes ago, F15Rules said:

...and the winner is....

David (@dweller25)!!!🤩

May I introduce "Superfox" 🦊🐺🦊🐺, a stunningly beautiful, and as new Vixen Japan SD115S, courtesy of Mr Tim Lumb, a real gentleman and all round top notch fellow..

And accompanied by an as new, almost complete set of Vixen LVW eyepieces..a full set minus the 3.5mm which my good friend Steve is now looking after.

I will post more details and photos shortly (after supper!) on a new thread in the Scopes forum.

I am thrilled.

Dave

 

 

Congratulations Dave - a superb replacement. Look forward to your impressions when you’ve spent a bit of time with the new scope. Particularly interested in practical issues - weight, ease of mounting, focuser, ergonomics. 

On 02/02/2024 at 21:00, Nigella Bryant said:

Hi Peter, to get high resolution of granulation, etc it depends on a number of factors including seeing. However the G-Band will enhance these with any size scope. I do use a 127mm achromatic scope at the mo stopped down to 100mm. The images I took above were taken with this along with a 3x barlow. You don't need an expensive refractor because you're only in one bandwidth. So a cheap refractor will suffice. My 127mm was just £250.

Fantastic image Nigella. Incredible detail.

1 hour ago, JeremyS said:

Didn’t you find it too bright there, Mark? 🤔

It’s the London light outside Kensington Town Hall I struggle with Jeremy. 

It was very busy today. Lot more people than I was expecting. Good to meet up with the night vision contingent and discuss all things image intensified. 

Without doubt people’s individual eyesight affects their ability to see differences between eyepieces. You need to tick several variables to get the best out of eyepieces: obviously seeing, position of target in the sky, type of target, collimation etc. But good eyesight is one of those variables - not only to appreciate sharpness, but colour and contrast too. 
But it’s worth repeating that, on axis, the differences between 95% of eyepieces on the market are very slim. With most expensive EPs, you’re paying for better edge performance and wider views in faster telescopes. 
A very small number of exceptional planetary eyepieces will show more detail on axis, using a combination of better glass, coatings and polish - but even then you need excellent seeing (and good eyesight) to really appreciate the benefits.
For many observers, the easiest way to ensure a step change in views - particularly of solar system objects - is to use both eyes and get a binoviewer. 

Though I’m now a confirmed refractor man, I started off with a superb Mak, and so retain a huge regard for them as planetary and double star scopes. I wonder if your impressions would have been closer if you’d used the same diagonal for both scopes throughout. That alone could have skewed the results towards the Tak - depending on the quality of the SW mirror? If it was the 2” dielectric though, it should be pretty good.

The problem I’m having is with small birds like warblers, trying to work out what bird you’ve seen fleetingly, with age and sex making things doubly difficult. But I doubt that even a £4k piece of kit like this would provide conclusive answers. 

On 18/01/2024 at 22:18, Sunshine said:

Oh my gosh, i was curious and looked on FLO’s website, the Lunt 60 configuration I purchased here in Canada is nearly double the price in UK when considering the exchange back to Canadian dollars, outrageous!

£4,000 for a single stack 60 with a B1200 blocker, which you really need for binoviewing. Goodness knows what the Feathertouch version costs now. What puzzles me is these dedicated Lunt scopes use smaller internal etalons, which is where all the cost is located. Yet the double stack 60mm etalon - a full 60mm aperture - is £1200 cheaper. Doesn’t make sense. It’s a real shame because they are lovely scopes, priced sensibly in some markets, but not in the UK.

Is already upsetting some birding purists. Like go-to mounts, night vision and smart scopes in astronomy, it rather hands things on a plate to the observer. I’ve reached a stage in birdwatching where many of the species I’ve yet to see are incredibly difficult to positively identify, so I say, bring them on. Brilliant technology, and if it helps people appreciate nature, then all’s good. But £4k!! I’ll wait for the SVBony version.

Excellent job Dave. Nice collection of eyepieces covering all needs. 

I don’t have any experience with table top dobs, but I’d have thought they’d be ideal for such a trip.
I’ve taken scopes in cabin baggage many times. I started with a 105mm Mak - it was great but not ideal for DSOs. Since then it’s always been refractors between 80mm and 100mm. I’ve settled now on a TV85 which is ideal, but (for example) an 80mm ED is almost as good. They really deliver - and provide the wide views that are so impressive in dark skies. The only drawback? Objects like globular clusters aren’t resolvable with just 80mm aperture. A Heritage or C5 might be a better choice for globs and galaxies.

They are not really designed for fast scopes unfortunately. On axis views would be great, but expect to see fuzzy stars around the field stop - even though the AFOV is relatively narrow.
I do like the idea of minimum glass eyepieces at lower powers though. Widefields tend to dominate at that end of the market, yet if you don’t mind a narrower fov, top quality minimum glass eyepieces (including the best microscope EPs) can improve transmission and contrast of DSOs - for example squeezing out more detail of galaxies and nebulae. 

I agree John - and the ‘several hundred £s’ is now rather more for all but the very cheapest dedicated scopes. Have a look at current new prices for the Lunt 60, and you’ll see that even this modest aperture scope, with a small internal etalon (cheaper to produce than the better performing, full aperture external etalons) is many thousands new. Double stacked is almost double the price. 

5 hours ago, Sunshine said:

This would indicate to me that you use a Quark? I say this because they have been known for inconsistency in their filter quality, but if you happen to score a good one I hear the views are second to none.

I’ve had various set ups - a Quark which was poor, two Lunts which were great double stacked but both (one in particular) underwhelming single stacked. A couple of Baader/Solar Spectrum Sundancers which were basically nice etalons, but with other (significant) problems, and a double stacked Solarscope 70mm, which is wonderful - though once again, nothing particularly special single stacked. I’ve learned enough to show that all brands are highly variable in both quality and bandwidth, but Quarks/Solar Scouts and Coronado are more variable than the others - a view backed up by specialist forums like Solarchat. But these are mostly cheaper, entry level products. Interestingly, the real Rolls-Royce etalons were produced many years ago by Solarscope and pre-Meade Coronado. Though if you dig into the history of commercial solar Ha filters, all four brands share a common ancestry. 
One thing’s for certain - Stu’s route is a very cost effective route to wide-aperture observing. But the Beast will require good seeing to really shine!

14 hours ago, Sunshine said:

I would agree that looking through H-alpha during solar minimum when the sun looks like an orange ball with a few dark spots can be underwhelming. There are those days (a lot recently) where there are no less than five proms, some are enormous. Those days are amazing, the beauty of an H alpha scope lies in it’s portability and ease of use, a scope small enough to keep right next to a door ready for a quick peek. One quickly finds that an H-alpha scope no matter how small it is, it will become a most used scope and one which will be greatly missed if sold. One more thing about HA scopes which is wonderful is outreach, it is much easier to draw a curious crowd on a walkway, park, or anywhere than night observing where less people are up and about. Curious folks are always blown away by the fact they are looking at the sun, almost everyone expects telescope to be for nighttime use but when passersby see me looking into the sun they cannot resist asking for a look, and the reaction is always the same “omg this is the sun? I see fire coming out!” this is great, I absolutely love solar outreach.

I’d agree on the reaction of the public - many are disbelieving of what can be seen in Ha if they haven’t looked through a solar scope before. 
Last year I was fortunate to catch an X-class flare develop and diminish in real time - it was without doubt the most spectacular thing I’ve witnessed since starting astronomy. Even after (I’d estimate) a thousand observing sessions over a decade, it’s still thrilling to be able to study our own star in such detail. The drawbacks are cost of course, and variability of filter quality, but Stu has shown it is possible to do things reasonably affordably. 

Brilliant Stu - it sounds incredible. Early morning/early evening solar sessions for the rest of 2024 I reckon. Particularly impressive that you’re getting such good surface detail. Kudos to Peter - an amazing scope.

Sorry to hear this and hope they are indeed ok. It’s why some eyepieces have undercuts! I’ve had a couple of scares with rotating binoviewers over the years, and undercuts have saved the day.

This is a specialist binoviewer - primarily designed for those who can’t reach focus with traditional BVs. The complex optics aren’t quite up to the quality of simpler binoviewers, and yes, it only offers a relatively narrow field of view. Certainly not ideal for DSOs. I’d only recommend it if you can’t use other units. At that price you could possibly get a Baader Maxbright II - with nice wide views, and excellent quality. Or the cheaper Chinese BVs (WO, OVL, TS, Celestron etc) are pretty good - narrower prisms though.

Then there was that bizarre Vixen 1.25” 100mm finder eyepiece, which I thought was an April fool when first pictured

On 02/01/2024 at 23:47, John said:

Celestron used to market the Japanese made Ultima eyepieces in long focal lengths. This was a 5 element modified plossl design I think. Here are the 45mm, 60mm and 80mm from that range, all in the 2 inch fitting:

 

Didn’t know about the 80mm - certainly never seen anything of that focal length here in Europe, apart from the 3” Masuyama 80mm. But that costs around twice an Ethos 21mm IIRC. I’m happy with the 67mm TeleVue which I use most nights with night vision. Did try it in a C8 once without night vision and it was pretty decent.

I would ask on solar chat - they’ll know about this filter. 
But have you tried the standard Lunt kit? I didn’t think the double stack 50 was dim at all. But you’ll be limited to powers up to about 70x - that’s more to do with the lack of resolution than brightness. For visual it’s critical that you cover your head and block out any external light. Then high power views are much more impressive.