John

1 minute ago, jetstream said:

Got to get you frac guys on the right track!

I'd miss my 12 inch dob more than any of my other scopes if I no longer had it

13 minutes ago, Stu said:

Wow, sounds amazing John. I knew Dartmoor was dark, but perhaps did not appreciate it was THAT dark. So glad you had three clear nights to make the most of it. It’s not so far for me now, so I’ll have to try to get up the sometime soon.

I can tell you Stu that my jaw nearly hit the ground when I stepped outside on the first of the clear nights

I've experienced a couple of dark nights at the SGL star parties but nothing like this.

I think the location of the cottage quite high up (for Devon) but in a valley and rather remote from other houses was a contributory factor.

8 minutes ago, Stu said:

 

Tee hee, both wrong I’m afraid, though Martin is along the right lines with larger aperture…

Got to have something worthwhile to use that Ethos 21mm in

I've just returned from a week under very dark skies indeed, the darkest that I've experienced as far as I can recall.

We stayed in a remote cottage deep in a valley on Dartmoor. No WiFi or mobile signal which is why I've not been on the forum for a week !

We had 3 nights of totally clear skies and they were fabulously dark. There are no street lights in the valley and only a handful of scattered cottages. When the lights of our cottage were turned off there was literally no man-made light around at all.

No moon intruding either so I had these wonderful late summer skies to myself and my 11x70 binoculars

Using the naked eye, the milky way was really obvious and bright from Cassiopeia through to Altair. It could easily be traced much further than that reaching down through Perseus on one side of the sky and down into Scutum on the other. The great dark rift in Cygnus was stark with the bright, dense star fields of our galaxy flowing like rivers either side of it.

Deep sky objects such as the double cluster in Perseus and Messier 31, the Andromeda galaxy were really prominent and easy to see even for my wife who usually struggles with anything faint. As my eyes adjusted to the darkness I found that I could see objects such as the North American nebula and, the bright globular clusters Messier 13 and 92 in Hercules without any optical aid at all. The last mentioned was not at the zenith and is magnitude 6.3 so I reckon the naked eye limit towards the zenith was around magnitude 7, possibly even better.

As Triangulum rose higher in the sky the misty patch of Messier 33 could be identified with averted vision and on and off, directly. That's not something that I've experienced before.

Using the 11x70 binoculars (hand held) was a further revelation. The sheer volume of stars, even in parts of the sky which I though were relatively barren from home, was overwhelming. Messier 31 showed not only it's bright core but the extended nebulosity of it's spiral arms extending well beyond the edges of the 4 degree true field of view of the binoculars. Added to that, Messier 32 and Messier 110 were very clear accompanying the Great Andromeda Galaxy.

Messier 33 was very prominent and took on an "S" on it's side form from the spiral arms.

In Ursa Major, Messiers 81 and 82 were very notable and both showing their distinctive shapes normally only seen with scope. U. Major's other notable galaxes such as M51 (two dim eyes) and the often elusive M101 were also straightforward binocular targets under these conditions.

Looking towards the zenith, Cygnus dominated the sky but the famous Lyra and Vulpecula planetary nebulae of Messier 57 (the Ring) and Messier 27 (the Dumbbell) were clear even at a paltry and hand held 11x. The highlights within the mighty Swan were the North America and Pelican Nebulae (NGC 7000 and IC 5070 / 5067) with their full forms and relative locations very distinct and to cap it all the whole of the Veil Nebula, the delicate feathery curl of the Eastern segment, the twisted spike of the Western and the very delicate tapering haze of Pickering's Wisp. Marvelous sights and truly memorable

The only astronomical equipment that I had on the trip were my eyes and my 70mm binoculars but under those skies they provided more than enough memorable sights. No filters needed, even for the nebulae.

Needless to say I will be pressing for a return to Dartmoor and it's skies soon !

I use both - the knobs with shorter telescopes and the cables with longer ones.

Sorry for the delayed response but I've been away under very dark skies but with no WiFi or mobile signal

Many congratulations on acquiring the 130mm F/6 APM/LZOS @Stu

I hope you enjoy it as much as I do my TMB/LZOS F/9.2 version

1 minute ago, Alan White said:

I think the flourescent ornage will suit Arcturus well.
Shows Steve's fine taste 😉
Oh and be very 1970's Celestron as well

My old Konus branded 150mm F/8 was not far off !

4 minutes ago, F15Rules said:

Yes, he didn't like Apo scopes, and later on seemed not to like refractors at all - despite having written a book about choosing and using a refractor telescope! 🥴

Yep - he was "converted" from traditional achromat refractors, initially by a mak-cassegrain 180mm and then by a Skywatcher 200P dob.

1 minute ago, F15Rules said:

Oh dear.. - white tube, but as for the other colours..and no rings at all!!..

Wrong glass as well - it's a "Poodle" as Neil English would have said !

3 minutes ago, Kon said:

Based on @jetstream and others suggestion on this forum, i bought this one:

https://www.firstlightoptics.com/televue-filters/tele-vue-bandmate-oiii-filter.html

yes it is pricy but once you see the Veil, North America, Pacman and many more it makes up its money; Veil alone was sufficient for me to justify its price. I am at bortle 3/4 skies using an 8" Dob. Have a look at some of the observing reports I have done using OIII and which other targets have benefitted.

Several discussions on OIII if you have a search at the forums.

 

Yep, that's what I would get if buying from scratch again.

Important to get the Bandmate Type 2 though. The Type 1's are still out there but are not as effective. Tele Vue switched manufacturer and spec for the Type 2 and that has really paid off.

37 minutes ago, dweller25 said:

OK, so as the OP is refusing to give teasers out 🙂 why don’t we just for fun and whilst our scopes are cooling down have a guess at what colour it will be ?
I will suggest a classic creamy white 😁

If it's not a white tube with black and / or brass fittings, it's plain WRONG !!!!!

1 hour ago, RobertI said:

One thing I have never got to the bottom of is the “Lanthanum glass” - much advertised with the TS and Tecnosky versions but not mentioned on the AA version - what is it (a coating, a type of glass, a process) and is it a “premium” feature or not? There seem to be a LOT of discussion on CN about this, some people even claiming it’s actually a way of reducing cost of making glass, so does not necessarily equate to high quality glass. Perhaps this is not the place for a long discussion on this, but would be interested if anyone has a definitive answer?  
 

I posed the question to AA and got a resounding silence.....

The most expensive glass will be the ED element - in the case of the ED 102R this is FPL-53 from Ohara. What matters about the 2nd element (the mating element) is that it is a good match for the ED element in terms of it's optical characteristics. To me this is more important than whether or not it is a lanthanum glass or not.

With the cost of using FPL-53 for the ED element it seems unlikely to me that a manufacturer would use anything other than a well matched glass for the mating element. In 2017 FPL-53 glass cost 18 times as much as the BK7 crown glass which would be used in an achromat objective.

So, personally, I think the lanthanum thing might be a bit of a "red herring".

3 hours ago, Voyager 3 said:

If you will be getting both , then get the UHC first . It is more universal and will give a huge boost for the more famous nebulae like M8 , M17 , M42 , M16 etc . 

 

The  get the OIII for use with some supernova remnants , wolf -rayet excitation nebulae , large planetary nebulae etc . 

The O-III is worth having for the Veil Nebula complex alone. There really is so much to see there

A UHC will show it but an O-III is has much more impact.

40 minutes ago, Alan White said:

Nice to read and confirms what many of us with ED100mm scopes think,
A great prtable sized and very capable scope size.

Tempted to try a 120-130 ED now?
 

Trouble is, it's really nice to have a 100/102mm AND a 120/130mm

Nice summary of the joys of a fine 4 inch refractor Rob

The run of focal lengths that I use with my 900mm focal length refractors (100mm and 120mm aperture) is:

24mm - 17.3mm - 14mm - 10mm - 7mm - 5mm - 4mm-2mm zoom

To be honest I tend to skip the 17.3mm very often and move straight from the 24mm to the 14mm. 

Don't know if that helps

1 hour ago, Nyctimene said:

Your report, John, prompted me to give Triton a try with my newly acquired 12" f/5 Dobson. Conditions were not great - NELM 5.0 (UMi); SQM-L 20.92; M 31 near zenith barely to make out. Seeing average. After warming up with Jupiter - prominent NEB, four moons (but no transits, no GRS); I started from Phi Aqr with Rigel and SkySafari, and found Neptune after five minutes of star-hopping with 58x mag. The blueish colour was not as obvious as I expected, and the tiny disc needed the magnification of 333x (9 mmf UWA+2x Abbe Barlow) for revealing. Careful observing the field for several minutes and using averted vision, I finally spotted the 13.6 mag Triton, popping in and out of view (as you described it) at the correct position in SkySafari. Later, I found out, that I had observed this moon almost at it's maximum separation from Neptune (which is 17") in 16.3" distance. This was the first time in five decades of observing, that I've seen Triton - admittedly, the first real try. Studying afterwards the article by Phil Harrington in "Cosmic Challenges" (no. 156), I learned, that Triton is the only (larger) moon in the solar system, that circles it's home planet  in a "backwards" way against the direction of Neptune's rotation ( indicating an origin of Triton perhaps in the Kuiper Belt, and a capture later in the gravity field of Neptune). The albedo is extremely high (0.75; our moon is just 0.12).

I had a short look at M 33 with 58x - no structure visible, but at least NGC 604 easily with direct vision. M 81/M 82 ended the session after 75 min at 01.30 CEST. Very pleased with the optical quality of the 12" and with the view of an extraordinary celestial target; and so to bed.

Thanks for reading

Stephan.

I'm so pleased that you have spotted Triton Stephan

That's a great report as well !

My Intes maksutov-newtonian model was the MN61 as I recall. The MN6 part makes sense but I'm not sure what the 1 signifies 

I use a sort of "1000 yard stare" approach when trying to spot faint point sources. Similar to the technique for viewing those "Magic Eye" 3D pictures. Deliberately de-focussing the target seems to help faint point source type targets to "pop through".

This technique has worked for me on faint supernovae and faint planetary moons.

I don't know what the science behind this is, but it does work

6 minutes ago, RobertI said:

Interesting looking mount, Bill seems very impressed and said it’s the first mount of this type he used where he felt he didn’t need slo mo controls. Not sure it would appeal to me though - I think for that price I would want slo mo, but it does seem to fill a bit of a price gap in the market (assuming $650 = £650).   

I certainly think there is a gap in the market that needs to be filled somewhere between the Skytee II and the ~£1K mounts such as the Losmandy AZ8, AZ100 etc.

I also agree that slow motion controls are very nice to have as well though.

I think the Bresser 152S / 760mm has a 4 element optical system. An F/10 achromatic doublet at the front end and a two element corrector further down the tube. There has been some argument over the years as to whether the design is a true Petzval type or not but it's along those lines. So pretty much as @Stu says.

I believe the colour correction is similar to one of the F/8 doublet achromats so still plenty of false colour but less than a doublet F/5 would show. The field is flatter with the quad design. They are quite heavy scopes and will require a stouter mount than your current AR 102 / 1000.

If the prime interest is in lunar and planetary observation there might be better options ?

10 hours ago, globular said:

 

...When the range first came out, however, they couldn't get the 17.5 quite right.... so brought out a 14mm instead.... as that was the longest fl they could get right.

When they finally cracked the 17.5 they brought that out too... but (rightly) didn't withdraw the 14mm.

That sounds a plausible explanation

I knew that I would regret posting that pic !

This one is new to me - the NOA CT-20 from South Korea. The author of this review (Bill Paolini) seems impressed !:

https://www.cloudynights.com/articles/cat/user-reviews/field-test-the-noh-ct-20-alt-az-mount-r3313

20kg carrying capacity from a 2kg mount head is quite impressive

There is a heavier duty one as well:

http://www.nohsmount.com/entry5.html

Just on the filters, I was happy with just an O-III (Astronomik) for a couple of years with my 12 inch dob. I have now also added a good UHC filter but the O-III gets much more use and has noticably more "oomph" especially on targets such as the Veil Nebula which is an absolute "must see" with a good sized dobsonian. 

With my 12 inch dob, which has a focal length of 1590mm, my most used eyepieces are 21mm, 13mm, 8mm, 6mm and 4.7mm. All Tele Vue Ethos's.

2 hours ago, Dantooine said:

Can someone explain why there is a 12.5mm being so close to the 14mm?

sorry if the question seems a little dim 😊

One traditional approach to eyepiece focal length progression is a 1.4x - 1.5x step for each focal length. 1.4x nearly fits with the Morpheus focal lengths apart from the 14mm which seems to be an "in between" focal length.

Others favour a 1.6x step - I guess it depends on the scope focal ratio as to what works best ?