John

The field stop of the 55mm TV plossl is close to the end of the chrome barrel to avoid vignetting. It therefore needs a lot more outward focus travel than most other eyepieces.

On terrestrial targets even more outward focuser movement is required to reach focus so that compounds the problem. A focuser extension tube or an eyepiece barrel extender (a better option) will sort the issue out.

The Tele Vue instructions explain this:

https://www.televue.com/pdf/literature/55mm Plossl and 41mm Panoptic.pdf

9 hours ago, Stu said:

Occultations are great. I love the way stars just blink out in an instant behind the dark limb of the Moon, it really shows they are point sources, vs a planet which takes time to go behind the limb....

 

Reminds me a little of the old fishing saying "the only thing more attractive than the appearance of a fishing float is it's disappearance"

Some observers in the USA who observe faint and far off objects with big scopes under dark skies came to the conclusion that the Zeiss ZAO orthos go the "deepest" followed by the Baader 10mm Classic Ortho, the 10mm Delos and the 10mm Ethos. All these eyepieces were deemed to be very good indeed and the differences slight, possibly only perceptible by the experienced observer with a big scope under dark skies observing challenging targets ?

Given the price of the Baader Classic Orthos it's quite a refreshing finding all the same

Yep, I agree with those points. I've found a set of scopes that are easy and quick to setup, can be moved around to get the best views, don't need cables, power etc and are quick to tear down and put away. It took me a while to realise what worked for me and what didn't and there were a few "bloopers" along the way which seemed a good idea at the time () but I learned from those and that helped make a better choice next time.

I'm lucky that the above can include a 12 inch scope so going reasonably faint and deep is practical. I do sometimes yearn for a larger aperture and have had to resist the temptation to acquire a 14, 16 or even larger scope a few times but I just know now that it would be a mistake in my current circumstances. Nothing sadder than a scope with huge potential that is not getting used.

Better than Ozzy Ozborne but not as good as AC / DC

6 minutes ago, Pixies said:

The Moon and Mars are in the same field of view in my 10x50 binoculars. The Moon is about to occult the star Mebsuta (Epsilon Geminorium) in a few minutes, too.

Nice !

I got some good views earlier and of Mercury.

A quick session on the nova and the heavens have opened and it's pouring down. Just as well my scope / mount were under the eves of the house !

1 hour ago, JAC51 said:

They are indeed excellent telescopes. I have aTMB 130/1200LW version from 2005, lens number 005. It has a draw tube and 2" Feather light focusser which I think is to make it bino friendly....

 

 

 

Welcome to the forum John

I have the same scope. Mine is #20 from 2006. Very fine scope optically and very nicely put together as well. Top drawer in my opinion.

I understand that the LZOS OK4 glass is somewhere between Ohara FPL-53 and FPL-52 in properties. A bit ahead of FPL-51. The key thing with LZOS is that they make both the OK4 glass and the bespoke mating element glass so the match and colour correction are excellent. Their figuring and polishing is done to very high standards as well so the resulting objective lenses are up there with the best.

This is what Professor Ian Morrison has to say:

http://www.ianmorison.com/everything-about-refractors-part-1-their-objective-lenses/

I managed to get some observations of the nova through cloud gaps using a 100mm refractor.

Comparing the brightness with stars in the same field, the nova seems not far off the same brightness as the star HIP 115691 which is listed as magnitude 6.6. I think I'd estimate the nova at magnitude 6.3 perhaps ?. So the nova might have dropped a magnitude since I last observed it on Monday 10th May.

I'll be interested to see if anyone else who sees it tonight concurs or differs with my estimate ?

(I'm not that experienced in making such estimates )

Still clear here and I have the 100mm frac out so I'll take a look in a few minutes.

I've had some nice views of Mercury this evening.

From our house I need to use an upstairs bedroom which has a nice western facing panorama of the river Severn estuary.

Following an imaginary line down from the crescent moon to where the Sun (and Venus) had recently set behind a cloud bank, I first found Mercury with my 11x70 binoculars looking quite bright and still reasonably high above the horizon.

I went to the trouble of carrying my 100mm refractor and a mount upstairs and was rewarded with some decent views of the 7.7 arc second desk and the fat crescent phase of the 40% illuminated Mercury at 125x through the double glazed window (not ideal ).

As the sky gradually darkened I could see Mercury clearly with the naked eye as well. Lovely sight with the crescent moon hanging up there.

As the skies were forecast to be cloudy tonight, it has been a nice bonus being able to unexpectedly view this little world

Just got to lug the scope and mount back downstairs now !

53 minutes ago, bish said:

So annoyed that at the weather.  Hoping for a break in the clouds,

Rather amazingly it's quite clear here at the moment. Very much against what is forecast though so I doubt it will last

19 minutes ago, DesertSky said:

I have read controversial posts about the quality of LZOS glass. Some say they are overrated because they are technically equivalent to FPL51 but not FPL53 or FCD100. Any comments about that?    

Welcome to the forum

I find the Baader twist lock 1.25 inch system deals with undercuts of all types / brands somewhat more effectively than the Takahashi compression system.

The Baader system uses lateral rods pressing against the length of the barrel whereas the Takahashi system uses quite a narrow compression collar.

4 minutes ago, jetstream said:

Heres one of the OP's questions- and I dont think there can be much debate over what it takes to see galaxies and DSO- its aperture. Or we can tell the member to drive to very dark skies with his 100mm, or better yet drive to very dark skies with a 10"-12" dob.

Good idea to re-visit the original questions Gerry

One of the things that has always impressed me about the Ethos eyepieces is the way that aberrations / distortions are controlled in the outer parts of the field of view. Quite frequently I have enjoyed observing a double star or maybe Saturn with the 6mm or 8mm Ethos and let the target drift right across the field of view until it is obscured by the field stop edge. I've been constantly surprised how a tight double star stays nicely split right up to the field stop and equally how fine details such as the Cassini Division remain sharp right across the field of view. 

Obviously Tele Vue will have accepted some form of optical distortion in order to obtain the very wide and sharp field of view with low levels of astigmatism even in relatively fast scopes but whatever choices they made seem to be the right ones as far as my observing eye is concerned at least. Whether my wallet is so keen on them is another matter entirely

That sounds about right.

I used to have a Meade Lightbridge 12 which weighed around 37kg in total.

My 12 inch Orion Optics is a lot lighter - around 27kg in total. No GOTO / motors of course.

I found the Lightbridge 12 too heavy for my liking. I could move it around in two parts but once it was set up it had to more or less stay put for the session. With my current dob I can move the whole thing (carefully) a short distance (ie: a few feet) to get the best views of the sky.

I'll bet there is still more of this stuff laying around in Gloucestershire fields:

https://www.bbc.co.uk/news/science-environment-57099789

The estimated retail price seems to have edged much closer to $400 now according to the vendors section of the CN forum.

If the optical performance is in the Pentax XW / Baader Morpheus ball park then that would be good value.

The views of the bright globular clusters with my refractors (100mm to 130mm) are nice, sometimes very nice. The views with my 12 inch dob can be jaw dropping.

I have owned a few 6 inch refractors as well but again, no competition for the 12 inch dob on deep sky objects from them.

While I do observe deep sky objects with my refractors, the dob is by far my preferred instrument for such visual astronomy.

I guess newcomers reading this thread might wonder why our experiences and preferences vary - the lack of consensus must make reaching a decision on instrument choice challenging 

It's just how it is with such discussions though. Once we can have star parties and outreach events again, the best thing is to get along to one and find out for yourself what floats your boat

Solid cloud and rain all day here

7 minutes ago, DesertSky said:

I would wait for some reviews to be published.

So would I.

Welcome to the forum

1 hour ago, Louis D said:

... Effective AFOV (eAFOV) is about 90 degrees for both variations on 100 degrees.

It's a pity that they have 100 degrees AFOV printed on them in big white letters.

Keeps the marketing people happy I guess.

39 minutes ago, Cyril said:

Any change in the countty's circumstances has always been followed by price rises,  today I found out that our local builders merchant's prices have risen by 40%.

 

https://www.theguardian.com/business/2021/may/08/cost-of-building-work-on-uk-homes-to-rise-as-price-of-materials-soars

1 hour ago, Louis D said:

If you are referring to the Meade MWA 15mm, they're actually not all that new.  In fact, they've been discontinued by Meade and are sold out at most retailers.

Here's a review of them under the Omegon Panorama II brand name.

I think those fall short of the full claimed AFoV as well:

https://www.cloudynights.com/topic/595495-omegon-panorama-ii/

Hello and welcome to the forum.

They are reported to be good eyepieces but their apparent field of view falls a little short of 100 degrees I believe. They seem to be measured at around 88 degrees.

Is this the one you have ?

https://www.cloudynights.com/topic/486454-15mm-meade-mwa-is-in/?p=6368899