John

You could put a 1.25 inch par-focalisation ring on the eyepiece barrel. This would lift it up a few mm and then it would clear that screw on the diagonal. For a solution that would help all eyepieces you could simply change the screws used on the diagonal for slimmer / longer ones ?

Sorry to hear of your accident @Mr Spock 😟

I hope you are feeling better soon.

If it is any small consolation, this happens to professional astronomers as well. I spotted this at the Lowell Observatory when I visited a few years ago. It is part of the mounting that holds the astrograph that Clyde Tombaugh used to discover Pluto. Clearly more than one person had suffered a "bump in the night" 🤪

When I bought and sold my TMB Supermono 5mm the used prices were around £100. Now they go for 4x-5x as much. 

@mikeDnight actually had and sold one of those many years back - for £90 I seem to recall !

I think now I'll stick with my Nagler 2-4mm zoom, XW 3.5mm and 5mm and Ethos 4.7mm I think. I did have a phase when I chased those ultra sharp, ultra low scatter eyepieces regardless of AFoV and eye relief but not nowadays 🙂

Interesting discussion 🙂

The only eyepiece in this sort of league that I've owned and used was the TMB Supermono 5mm. Superb performer but the tiny AFoV (~30 degrees), miniscule eye lens and very short eye relief became tiresome quite quickly whatever the quality of the view though it.

Which is the best option for those who need or like longer eye relief these days ?

These "top tier" performers as discussed here are superb I'm sure but I think they all have 12mm or shorter eye relief as I recall ?

I guess the TV DeLite might be the next best thing but with the additional eye relief for those who like that ? (I've not used a Delite I ought to add)

Excellent report and sketches 🙂

I agree 100% that globular clusters benefit hugely from additional aperture, perhaps more than any other type of deep sky object. The views with 10 and 12 inch scopes of the brighter GC's really do start to resemble images taken of them. I observed two of the targets you mention (M51 and M13) quite a few years back with a 20 inch dob from a dark site and the views were simply jaw dropping - I can clearly recall them even now. 

With M13, it is worth backing off the magnification slightly and trying to spot the magnitude 12 galaxy NGC 6207 which should be in the same field of view at lower powers. NGC 6207 lies around 1 degree to the NE of M13 and at a distance of 30 million light years.

Getting those 35mm eyepieces to reach focus can be a challenge even without a binoviewer - I used to have the Celestron Ultima version but could not get it to reach focus even without a BV in place when used with the TAL 100 RT that I had back then. 

The 35mm's of that design need more inwards focuser movement than any other eyepiece that I've used. This is because the field stop of the eyepiece is positioned well above the shoulder of the eyepiece (which is where the chrome barrel meets the black eyepiece body). Most eyepieces have their field stop more or less at the shoulder or a little below it. With these 35mm's the field stop is so wide that it cannot be accommodated within the constraints of the 1.25 inch barrel so they moved it upwards and consequently they need that much more inwards focuser movement.

They are lovely eyepieces when you do get them to reach focus and I'm pleased that you have found a way to use them with your new BV's 🙂

Whatever our feelings, to me it is rather sad that an experienced member of this community is left feeling so bitter after taking the trouble to post a comparison report on the forum 🙁

I can recall a time when, at SGL star parties, we used to take the mickey out of the "Takahashi Alley" brigade that was found at major star parties, mostly on the grounds that they could be rather condescending to those who chose and used other brands. The brand does seem to have come to dominate a number of parts of the forum now. Perhaps SGL is becoming the new "Takahashi Alley" ?

It is also disturbing that this is continuing in other threads and the mickey being taken of other peoples views repeatedly. Not really in the spirit of what SGL is about, or was about at least.

I own a scope of the brand in question and can tell you that all this swaggering stuff is making me rather embarrassed about owning it and posting about it, rather than increasing my enjoyment. 

I'm not at all surprised that @Mr Spock (Michael) feels the need to step away for a while. I did, for a year, and have found it quite difficult to get back into the forum - it seems to have changed and, sadly, is creeping away from the things that we said set it apart from other forums. 

I have no way of knowing but I wonder if there are quite a few members who feel similarly ?

The scope that I feel most affection for is my Vixen ED102SS. I've owned it for 16 years and it is a very versatile workhorse being able to show 4 degrees of sky and also perform sharply at over 200x magnification. It also sits happily on a lightweight mount such as a Porta, AZ-4 or even the AZ-3.

It is not my best performing scope but that's not the point of this thread as I see it, the Vixen always puts a smile on my face when I look though it and having done lots of outreach sessions with this scope, more people other than myself have got to look through it, which I feel is important as well 🙂 

Interesting reading about these top tier planetary type eyepieces 🙂

As @Deadlake says, with the seeing excellent tonight it is a good opportunity to press on the power. 

I don't have eyepieces in the league of the Vixen HR's or TOE's but I have taken the opportunity to compare my Nagler 2-4mm zoom with a Fujiyama HD 4mm ortho that I have had knocking around for quite a while. I was pleased to see that the Nagler zoom produced entirely comparable lunar and double star views both in terms of sharpness and contrast. Given the eye relief 10 degrees additional AFoV and zoom ability, that is quite a fine achievement from the Tele Vue folks. IMHO.

The scope was my LZOS 130 F/9.2.

It seems crazy that most of my observing tonight has been done at 300x plus but it's been that sort of night 🙂 

And, yes, I used 2mm as well at times 😄

Now it's dark, the 130mm with that "pesky moon" as an imaging friend of mine calls it 😄

22 minutes ago, Captain Scarlet said:

I only started observing when Jupiter was down at the start of its “low years”. Now it’s going to be higher and higher over the next 2-3 years I cannot wait, especially as I now have that much more experience and equipment. I am one of those who has still not had anything near a startling view of the planet. I have properly just about discerned the GRS and its colour only once.

Your lovely new 140mm refractor will really be able to "strut it's stuff" on the planets soon Magnus 👍

4 minutes ago, Alan White said:

You are in luck John,
your conditions must be far better than I fared,
enjoy.  🙂

 

I think the east of the UK might have been more affected by the Jetstream tonight ?

I hope you enjoyed what you saw all the same Alan 👍

Moon now clear of the conifers and looking really good. I'm "cruising" at 343x just now taking in various sights. The lava-filled crater Wargentin close to the larger Schickard is well illuminated tonight. The crater floor looks clearly higher than the surrounding landscape and there is a subtle raised "Y" shaped ridge-type feature (Charles  A Wood calls it a birds foot) extending across almost from rim to rim.

6 minutes ago, JeremyS said:

I was shocked by the colour in Jupiter’s bands when I first turned my M210 to him.

When Jupiter was higher in the sky in past years I've had a similar shock observing with my 12 inch F/5.3 dobsonian. Especially when there was still plenty of light left in the sky - the colours seemed even more startling then.  

3 minutes ago, Littleguy80 said:

Nice! Interesting that he’s using a larger Newtonian without a filter. My instinct was that it would be quite bright and hard to make out detail. Definitely planning a go with the 10” dob now  

I remember observing Mercury at one of the SGL Star Parties with my 12 inch dob. It was low down but well worth doing. The phase was clear. I didn't see any detail on the disk but then I'm not that experienced as a planetary observer.

30 minutes ago, John said:

Just out to the 130mm refractor after supper and an episode of "Fringe". The seeing seems better tonight. First target is Tegmine / Zeta Cancri. Straight in with the Nagler 2mm-4mm zoom. At 4mm (300x) the image of the triple star is super sharp and it stays looking that way to 600x when I run out of eyepieces unless I want to add a barlow to the zoom 😲

Looking forward to the moon with seeing like this 👍

I got to 900x (3mm zoom plus 2.5x barlow) and the stars in the trio are starting to look a little fuzzy around the edges. So it's not quite 1000x seeing tonight 🙄

Dropping back to 400x and everything is really crisply defined again. It's a bit crazy really 🤩

Moon is taking ages to clear the conifers tonight - I guess I'm a bit impatient !

Just out to the 130mm refractor after supper and an episode of "Fringe". The seeing seems better tonight. First target is Tegmine / Zeta Cancri. Straight in with the Nagler 2mm-4mm zoom. At 4mm (300x) the image of the triple star is super sharp and it stays looking that way to 600x when I run out of eyepieces unless I want to add a barlow to the zoom 😲

Looking forward to the moon with seeing like this 👍

4 minutes ago, Alan White said:

Who needs one, when you can have the super ED and now SD scopes.

And super achromats apparently - much debate elsewhere on what constitutes one of those, as you can imagine !

Gassendi was the centre of my attention last night, with it's network of rilles. The Apollo 16 crew took this oblique angle photo of the crater nearly 51 years ago:

I'm all set up with the 130mm refractor this evening so hopefully more lunar marvels 🙂

Not dark yet but we have a cloudless sky here this early evening so I've popped my 130mm refractor out to cool down 🙂

13 minutes ago, jetstream said:

I think but dont know that the term diffraction limited is a description of an optics ability with regard to angular resolution which may not describe everything we see on the moon and planets....

 

That is a good point. Many features are more about contrast differences rather than angular resolution. I think this is where Modulation Transfer Function (MTF) comes into play but it is also where my knowledge peters out so I can't "shed any light" on MTF really 😄

My understanding of the term "diffraction limited" is that, seeing conditions allowing, the optical quality is sufficient for the instrument to perform to the theoretical limits of the aperture. 

There seems to be a view that seeing conditions, much of the time, determine the effective limit above a certain scope aperture but there is much less agreement, probably understandably, on what that aperture limit is. My guess is that it varies widely.

The actual optical accuracy tolerances to achieve "diffraction limited" in a scope seem relatively relaxed compared to many of the strehl / PV / RMS statistics that we often discuss these days but I don't know if an optical system can actually exceed the theoretical limits for it's aperture and therefore be "diffraction exceeding" ? It sounds doubtful to me but you never know 🙂

I suspect it's more likely that the better optical quality shows itself in being able to "see" to the theoretical limits a little more easily and under a wider range of seeing conditions ?

Perhaps not quite the same question but I have noticed that with eyepieces and scopes, good to excellent seeing conditions helps the better optical quality to stand out a little more.

During more ordinary or lesser quality seeing the performance gap seems (to me) to be narrower or even non-existent.

I have also noticed that smaller aperture scopes (refractors in my case) seem to make more of whatever the seeing conditions are than larger aperture ones although the larger apertures show their additional potential under good to excellent seeing. Likewise when observing targets that are not far above the horizon.

Not sure how those observations help, but that is what I have experienced 🙄

11 minutes ago, Franklin said:

@Mr Spock started a great thread comparing a couple of fine refractors. I've just returned to read on and tbh I'm a little lost, which is the best scope again? The Starfield or the Tak?😁

Very nearly a dead heat. 

Until some bright spark DPAC tests a Starfield and shows that it can't be 😜

3 hours ago, JeremyS said:

Don’t think that’s relevant John, or fair, considering this well documented, and unfortunate, saga.

His results clearly showed that SV methods were erroneous as they optimised lens performance in red, not in green - or even across a range of colours. Seems even SV admit that. The question that remains is whether this has affected smaller apertures than the one tested. Evidence from users is that they are fine.

Well it certainly is well documented 🙂