Highburymark

11 hours ago, Paz said:

If you want a really solid connection to the scope,  a t2 to 2" adapter is good, and if you want to be able to swing the eyepiece to the side easily a heavy duty t2 quick changer and bayonet would do that.

I don't really use 1.25" into the scope these days, only 2" or 2" to t2 for the solidity.

Snap - this is what I do on all my scopes, with T2-2” adapters in the focuser, T2 Baader diagonals and heavy duty changers, and either 1.25” or 2” clicklock EP holders. They make undercuts irrelevant, and the whole system is extremely strong (and flexible, if you need to rotate a binoviewer or eyepiece for example). Adding T2 spacers is easy to vary barlow powers, and it’s surprising how few 2” eyepieces vignette with a T2 diagonal. Finally, it’s light and offers a short light path. 

Nice report on a clearly excellent eyepiece. I haven’t experienced any of the flat field line yet, but the 30mm in particular seems to get universally praised. Great to bag so many targets in one session - thought I detected the influence of Starsense.

2 hours ago, Don Pensack said:

My advice is to achieve the longer f/ratio with a 25-26mm Plössl and a 2X Barlow instead.

You will still have a 45-50° apparent field instead of a 28° apparent field (55mm 1.25" Plössl)

The problem is to achieve the very lowest magnification possible through a binoviewer, through this frankly ridiculous optical path:

ERF - 120mm refractor - 2x extender - solar filter incorporating 3x barlow - binoviewer - eyepieces.

Even 40mm plossls are too much. If some enterprising designer could make a pair of 1.25”, 100mm lightweight eyepieces, with 15mm eye relief, a decent AFOV, and minimum glass, that would be perfect…… It’s a question for another thread, or perhaps another universe.

2 hours ago, John said:

No problem Mark  - interesting challenge🙂

In the 1.25 inch fitting, 40mm plus focal length eyepieces are scarce. Vixen used to have a 45mm version of their "silvertop" range but they are quite hard to find singly, let alone as a pair. There was a Celestron 42mm Ultima (old, Japanese series) but that might not be long enough for your needs. 

 

Very interesting - didn’t know about the Vixen 45mm. Suspect as you say it might take a few decades to track down a pair

On 22/04/2023 at 20:08, John said:

Talking of eyepiece regrets, one that sticks in my mind was the 55mm plossl that I bought from I R Poyser. I've nothing but admiration for what I R Poyser do regarding traditional refractors etc but I really should have realised that a plossl eyepiece in the 1.25 inch format using 55mm focal length ex-military optical components was never going to be a good idea for me 🙄

The finished eyepiece had no eye guard and the field stop was provided by the bottom end of the 1.25 inch barrel. The eye relief was probably about 40mm so I had to "float" my eye that far off the top lens of the eyepiece. I don't think any of the lens elements were coated either. I thought that a 55mm would give me a "massive" true field of view with any scope that I felt like using it in but soon found out that holding the exit pupil that far off the top of the eyepiece was very difficult and the true field was (of course I now know) no larger than a 32mm or 40mm plossl in that format could give. 

All in all a disappointing and frustrating experience in my early days of telescope use and observing. I think I did learn a thing or two from it though 😉

Some of the components of that eyepiece are still rolling around in the bottom of my "bits" box I think, just in case I could think of something better to do with them 🙄 

I R Poyser have also come along way since then and produce some mouth watering scopes:

  Brass Telescopes | IR Poyser – Telescope Makers

This is exactly what I need now - a pair of 1.25” 50/55mm plossls, though I have the excellent TV40s. Why? Because I have a solar Ha filter that needs as slow a light beam as possible to show surface detail well - so ideally I’d stick a 2x extender in front of the 3x barlow/extender built into the filter. Trouble is, that would still give me far too much magnification with my TV40s in a binoviewer. A pair of 55mms would be perfect - though not even I am demented enough to try two TV55s in a 2” binoviewer. 
Yet there may be a solution. I believe Russell Optics in Vermont does a 50mm 1.25” plossl. But I’m sure they would be extremely challenging with eye relief. Don’t know if Louis or Don have any experience with Russell, or even more unlikely, with such an unlikely eyepiece?

Apols for diverting the thread anyway….. I liked your story John

13 hours ago, Alan White said:

Yes, just collected it today. See the Postman thread for images etc.
Quick peak in WL with the 1.25 Lunt wedge,was quick as far too small a heat dissipation for the scope size,
Its stunning, so the 2” wedge should sing.

Nice Alan! First view I ever had through a Herschel wedge was with a 152mm F/5.9 - Altair I think. It should really shine in early morning and late evening, when atmosphere is steadiest, and lets you go above 200x. 

Personally I wouldn’t risk anything in the hold. You could end up without anything to enjoy those dark skies.  
The scopes I’ve taken as hand luggage are:    
4” Maksutov - really not the right scope for DSOs, and as a fellow city dweller, it was an unsatisfying travel scope.   
80ED Equinox - excellent all rounder. 
100mm Apo, minus the focuser and dew shield to fit into hand luggage - pretty much a dream set up.    
85mm Apo - my current set up. This is the one I’ll stick with. There is so much to see travelling when you’re not used to dark skies that the slightly small aperture isn’t really an issue. 
If you’re determined to take a larger scope, I do like the idea of a C5 though - and you wouldn’t need to risk it in the hold - it would easily fit into hand luggage. 

My problem is that I can’t sell things, even though I don’t really need them. This is a luxury that will come to an abrupt end when I retire in five years, (or when my current job finishes me off before I retire, which right now looks fairly likely.)     
I have three pairs of exceptional Zeiss and Leica 25mm microscope eyepieces - even after a year’s testing, I still find it impossible to split them. I have an excellent full set of Kasai orthos that I don’t use very much. And I have a Delite 4mm that is outshone by the TOE 4mm, but I haven’t yet summoned up the courage to sell.     
Of the eyepieces I’ve sold that I remember with nostalgia, I’d include Delos 10, Ethos 13, and Panoptic 35 (all too heavy when I downsized), Nagler T6 11mm (I had Delite and plossl 11mm, so couldn’t justify the Nagler too, though it was superb), and finally Celestron Ultima 30mms, a wonderful binoviewing pair (which I only sold because Steve/Saganite - who had originally sold them to me - wrote me a very nice note a year or two later saying if ever I thought of sellling them again, to please bear him in mind….).    
I had a pair of TV 32mm Plossls covering that focal length…… though the Ultimas were just as good…… couldn’t justify both pairs, so how could I resist Steve’s plea?

I’ve had a couple of problems with Baader recently too Stu. They set such high standards it’s surprising when anything falls short.  
I raised an eyebrow at the extra charge for the polarising filter too. Whatever happened to white light being the cheap way into solar astronomy? Still - should be a great piece of kit when it’s sorted.

On 18/04/2023 at 15:20, Stu said:

My second pair of Baader Maxbrights…. No picture as you know what they look like. I will have matched sets for WL and Ha now, perfect.

I’m waiting for my Mark II CoolWedge to come back as it had to be returned, will post about that elsewhere. Should be able to do a comparison with the mark I.

Look forward to hearing about the new wedge Stu, particularly if any visible benefit to the narrower Continuum, though I can imagine it won’t be easy to compare with the old one.
Are you still using the MkIV for white light - or moved to the MBII? 

Fantastic - what a great story Mike. Thanks for posting.

Chroma 3nm Ha is the best filter I’ve got for night vision nebulae from London. It also proved a good investment. About two months after I’d bought the 2”, prices doubled over night. This was even before COVID.

For night vision stars, globs and galaxies, Baader 685nm IR pass.

Baader Continuum and polarisers for white light. Occasionally Astronomik UHC, Lumicon O III, if I’m travelling.   
And biggest of all, a 120mm Baader ERF for solar Ha.

Even though he had a great sense of humour, I loved how Sir Patrick would get deadly serious whenever the subject of astronomy or telescopes came up. This photo captures that perfectly. 

In 2007 I eventually got to play with it during our stay at Patrick's. It was at that time in need of some TLC. Of course it has since been renovated. I wonder where it is now?

Would like to hear more about this Mike

Looks as though it might even lift off. That would be spectacular.

It’s been developing for a while, so not ‘hot off the press’ news, but this magnificent prom is well worth a look right now.

Yep - the build quality of Lunts is remarkable. Very solid pieces of kit. A joy to own and use. The only thing letting the old LS60 down was that so-so focuser.

12 hours ago, Louis D said:

So what's keeping the 40+ countries in Europe from designing and selling their own high spec NV sensors?

They already do - my night vision tube is made by a European company called Photonis. They are freely available - not just to military buyers. But they tend to be pricier than their US counterparts, and use slightly different technology. But very good quality.

1 hour ago, mikeDnight said:

It makes me glad I'm a visual only observer. I'm happy with 15 minutes here, 30 minutes there. Many times I've waited patiently under seemingly blanket cloud, when suddenly the sky has cleared for an hour with perfect seeing, or brief spells of observing through sucker holes. I can manage some quality observing in just one hour!

I agree Mike! I’m more frustrated by poor seeing than cloud, which I just accept as inevitable, but I still enjoy every moment I spend observing. 

5 minutes ago, John said:

Is the availability of high spec NV sensors still impacted by technology export restrictions, primarily in the USA, or have things moved on from there now ?

 

It’s still the same as far as I know John.

Well let’s face it, night vision has been a huge flop in this country. It needs to be said. 
If ever there was a solution to light pollution (apart from an energy crisis forcing bills up by thousands of pounds - that would certainly encourage people to turn off pointless lighting 🤬) night vision was it.
Yes, it’s expensive, but no more than many people spend on a top notch dob or refractor, or even a relatively small solar Ha scope. Yet, rather than become mainstream, it remains the pastime of a few oddballs, misfits and weirdos. Like me 🧐.    
I’m surprised how few people have embraced it, but I completely respect and understand why. I think, on the whole, the amateur astronomy market is a pretty conservative one (with a small c that is). And that’s why the answer to the OP’s question is probably, there won’t be much change over the next decade or two, beyond what we’ve seen in the past decade. More imaging/faster scopes/harmonic mounts etc.

3 hours ago, Saganite said:

Hi Mark,

The FT 3" is on the 6" APM at the back.  The Vixen has the 2.5" FT 2525 HD focuser.  This can be bought with the adapter ring shown. The problem is it has a 88.5mmx 1.0mm pitch thread. It was this adapter that I sent to Mark along with the Vixen focuser shown.  The Vixen tube is threaded 88mm x1mm pitch, so it would not fit, but I knew that a competent machinist could 'chase ' the thread and make it fit, which is what Mark did, superbly well.

Thanks - I  wasn’t aware they even did a 2.5” range. What a great option for your Vixen. Though FT focusers are not easy to get hold of these days, new or used. Starlight seems to have a long waiting list.

On 06/11/2022 at 09:17, Saganite said:

My lovely Vixen ED103s has appeared on here before, but not looking as  beautiful as now.  The Feathertouch focuser shown was never meant for the Vixen because they do not offer an adapter to fit this model.   When this appeared for sale I immediately wanted it because of its 95mm of travel.  The adapter thread was 88.5mm x 1mm pitch, whereas it is 88mm x 1mm pitch on the Vixen OTA, but I knew it would be a simple job for Mark at Moonraker to chase the thread and that is what he did for me, in short order ....top man .

Until this year I had never used a Feathertouch focuser, and now I could never go back, they are sublime.

 

Which Feathertouch model is that Steve? Looks like one of the 3” range - and looks wonderful. Didn’t realise Moonraker provided bespoke adapters.

On 15/04/2023 at 02:15, Sunshine said:

Good point about trying higher power with these new ED doublets, i tried out my 5mm XO  (85x) while focusing on one particularly bright prom and even though the sun was only half an hour to setting I was impressed with the sharpness.

I have an XO5 too - haven’t thought about using it for solar as I mostly binoview, but I shall give it a go next time the clouds part - so around July 2030 then……

They look very nice indeed.
I see Lunt has just replaced it’s (wrong!! - why does spellcheck keep changing its to it’s for the possessive? A real bugbear of mine) old solar eyepiece range with the flat fields. They must be a contender for the most badged-engineered eyepieces on the market. Good value though. 

4 hours ago, Don Pensack said:

Especially the 6mm Ethos, which is one astounding eyepiece.

The specs:

Tele Vue, Ethos

6

100.7

<2

3.5

5(7)

diffr.

diffr.

diffr?

 

The first three figures after the 100.7° measured apparent field are the spot size at f/4 in center, mid field, and edge of field.

The last 3 figures are the spot size at f/10

The parenthesis on the f/4 edge of field is the actual length, radially, of the star image.  What we see is the smaller figure.

Anything less that 10 is seen by the eye as perfect.  Diffr. means limited only by the diffraction in the scope.

In seeing that allowed me to go to 3.7mm, the 6mm was as sharp as any planetary eyepiece I've ever seen.

If 6mm yields a high enough power, the 6mm Ethos is excellent.  For any use.

 

 

How do those figures compare with the shorter focal lengths in the Ethos range Don?