John

31 minutes ago, JeremyS said:

....I must admit a secret obsession has become fine double star splits associated with fine diffraction patterns 😊

I enjoy these very much as well. I have to say that the Vixen delivers more than my Tak on this. The Tak objective is probably a little better overall and the diffraction rings are that much thinner and fainter. One of my favourites for diffraction rings with the Vixen is Gamma Virginis (Porrima) - two very similar stars close together and fully framed with delightful overlapping diffraction rings 😁

Just now, JeremyS said:

If I were to factor in my friends astigmatism, that might be the clincher against the N31.

But the E21 is quite close to my E17. And heavier…

I had the E17 and it is a very fine eyepiece. For some reason though I've never found 17mm a frequently used focal length. I tend to jump straight from the 21mm to the 13mm. I've owned and let go 3 really good 17mm eyepieces over the past 5 years - the E17, the ES 92 17 and the Delos 17.3 so it must just be an FL that does not quite suit how I observe. Nothing wrong with the eyepieces at all - they were all superb.

2 minutes ago, JeremyS said:

Perhaps B is a bit too faint

Yes, that is what I am thinking.

5 minutes ago, JeremyS said:

So overall how do you compare (or like) the N31 vs E21, John?
If you had to choose for your 4/5 inch fracs.

Asking for a friend….

 

If I had to do without one of them it would be the Nagler 31. It's a great UWA eyepiece but under my bortle 5 skies the additional magnification provided by the Ethos 21 just produces more contrasty views of nebulae and galaxies plus that darker background sky. The Nagler does the Veil plus the N A nebula really well but for most other deep sky targets, the Ethos would be my tool of choice.

2 minutes ago, JeremyS said:

Nice result John. How did the diffraction rings look

I must admit a secret obsession has become fine double star splits associated with fine diffraction patterns 😊

I had a neat, thin, diffraction ring around the brighter component A (mag 4.7) but I could not see a ring around the fainter component B (mag 6.2).

1 minute ago, JeremyS said:

If i remember well, you have an Ethos 21, John. How does the view compare with the N31 on this target? Difficult to get both components in, perhaps, but otherwise.

I didn't use the Ethos 21 this evening Jeremy but from previous experience it will show the E&W sides of the Veil in the same FoV as well and the additional magnification gives even better contrast plus a darker background sky. The slightly smaller true field that the E21 gives means that the E&W portions of the nebula are very close to the field boundary though. The Nagler 31 just gives that bit of sky around the whole complex framing it in a more satisfying way, IMHO 🙂

19 minutes ago, JeremyS said:

Good luck for a fruitful night, @John 👍🏻

Thanks Jeremy.

Some clouds plus a bright moon are now creeping into view so I'll pack in shortly.

To show the versatility of the Vixen scope I've just managed a really nice split of the A-B pair of Mu Cygni. The Stelle Doppie database has these at a separation of 1.51 arc seconds plus there is some brightness variation between them as well.  At 221x the split was unmistakable. Like a tiny snowman with a thin black belt around his waist 🙂

Yay !! - clear sky, quite transparent and decent seeing as well. Don't know how long it will last but it is SO nice to get out with a scope again 😀

Cygnus is flying high overhead so I've been using my Vixen 102mm F/6.5 with the Nagler 31mm and Lumicon O-III filter to observe the Veil Nebula. With the eyepiece delivering a 3.8 degree true field with this scope I can fit both the E & W portions of the Veil in the same field of view with Pickerings Wisp showing nicely too.

One of my favourite summer views 🙂

Last time I imported something from the USA (an eyepiece) the import duty plus handling fee added around 22% in total to the purchase price.

Truss tubes don't always equate to weight savings. The Skywatcher flextube dobs actually weigh a little more than the solid tube versions. They are more compact to store and move around though.

Has anyone used one of these 2 inch format long focal length eyepieces in a refractor with a focal ratio of F/7 ish ?

I'm wondering how they do, edge correction and other distortions at that focal ratio, actual AFoV delivered etc, etc.

Can anyone shed any light (so to speak 🙂) on these ?

StellaLyra 40mm 2" KITAKARU RPL Eyepiece | First Light Optics

StellaLyra 45mm 2" KITAKARU RPL Eyepiece | First Light Optics

Many thanks in advance 🙂

2 hours ago, Epick Crom said:

Well here in the west coast of Oz we've been having our fair share of cloudy nights as well, but last night was clear as a whistle. Some highlights from my observing session with my 10 inch dob:

Getting a clear view of Mars as a tiny orange disk.

Super view of Mercury, almost at half phase.

NGC 6067 open cluster in Norma was amazing, very rich.

NGC 6321 open cluster in Scorpius was absolutely blazing as it was at the zenith and transparency was excellent.

NGC 6025 open cluster in Triangulum Australe looked great, it has a broken circle of stars close to its centre.

NGC 5139 Omega Centauri was the highlight of the night. A massive ball of countless stars fully resolved. Wow!

Then I got my first glimpse of Saturn this season, 15° up. Nice to see the gas giant again, it's rings noticeably more narrow than last year.

 

Wishing all my northern hemisphere friends clear skies!

Joe

Thanks for posting this Joe - it gives me hope 😀

2 hours ago, Mandy D said:

I was, honestly, very surprised at the weight of the 300PDS. I'm used to being able to pick up any of my existing OTAs with one hand, even the 250PX, but this one is a whole new ball game. The 300PDS is f/4.9, so ought to be lighter!

20% more glass and maybe slightly thicker as well as the additional tube size ?

11 minutes ago, Mandy D said:

For information purposes, my new Skywatcher 300PDS OTA, complete with rings and a Losmandy dovetail was weighed at RVO and tipped the scales at 26 kg.

My old Orion Optics F/5.3 OTA, similarly equipped, weighed around 17kg.

1 hour ago, Mr Spock said:

Ah, a yellow... Konus? The chromacor idea was a good one had it been executed properly and had a different person behind it 

Yes it was a Konus 👍

I owned 3 Chromacor's in total including one of the very rare Mk 2's and, properly matched and installed they all worked excellently in terms of turning an achromat into the equivalent of a good ED doublet. That was at the time when a 6 inch ED doublet cost several thousand £'s, if you could find one at all. Far, far better than filters with an achromat but also far more expensive. 

A properly matched Chromacor corrected SA as well as CA which is sometimes overlooked.

Today they would not make much sense in 150mm or smaller apertures of course - you can get an ED doublet 6 inch for around £1,800 and the Chromacor's cost around £800 apiece even pre-owned (which they all are now !)

A Chromacor might make sense today if you have a very large  (say 7 inches plus) aperture achromat of around F/8-F/10 though. An ED doublet or triplet of that aperture is going to set you back £10K plus so using a Chromacor might make sense.

19 minutes ago, DirkSteele said:

I can whole-heartedly recommend it to anyone who has the money. Mine is woefully underused but one day I will build it a little house and then it collect all the starlight it deserves.

My only 1st hand LZOS experience is with my 130mm F/9.2. It is quite probably the best scope, in terms of outright optical performance for it's aperture, that I have ever looked through 🙂

I owned a "yellow submarine" a few years ago. Definitely NOT made by TEC 🙄

I had a lot of fun with it and a Chromacor 0-1 though 😁

APM have a pre-owned LZOS 180 F/7 for sale currently. It's listed at just under 24,000 Euros (excluding tax) but I expect they will negotiate, a little 😈

6 hours ago, Andylast said:

Trouble is I already have a 7mm Pentax. Getting a 6mm would be an unnecessary extravagance. With long focal length telescopes the gap between 7mm and 5mm would be noticeable.  The other option is a quality 2x Barlow with the ability to remove the lens group to attach directly to an eyepiece to give 1.4X or 1.5x. That gives me a range of powers with the eyepieces I already have.

Below 8mm I do have 1mm increment steps and even go down to .5mm steps below 4mm. My scopes are shorter focal length than yours. Having more magnification steps for higher powers is very useful I find - you can find the "sweet spot" that suits the conditions and target with more precision. I guess it can seem extravagant though 🤔

If you can find one, an Orion Optics (UK) 12 inch dob weighs about the same as a chinese (eg: Skywatcher, Bresser, GSO) 10 inch dob. 

I really like the Vixen SLV's as well 🙂

Personally I might be tempted to get the 6mm for the 6 inch SCT which will give a useful 250x and the  9mm or 10mm for the 11 inch sct which gives 311x or 280x.

While "maxing out" possible magnification is fun sometimes, a wee bit lower than that is usually much more useful under typical UK observing conditions. I can't see the 466x that the 6mm would give in the 11 inch being used to often to be honest with you.

Here are a couple of pics of my TMB/LZOS 130mm F/9.2. My main reason for posting them is to bump this thread so that folks get a chance to have a look at @stuy's magnificent 228mm F/9 LZOS a few posts back up the page - it's well worth a look - there are very few around, anywhere 😁

Anyway, here are a couple of my scope - then scroll up for the big one with nearly 100mm more aperture 👍

Do you wear glasses when observing Andy ?

And what SCT's do you have ?

39 minutes ago, Pawel582 said:

they dont have cement optic

The glass elements in binoculars are usually cemented together. The eyepiece and the objective lenses will comprise of more than one glass element and these are usually cemented together in binoculars. Cement in this context means a type of glue.

3 minutes ago, Cosmic Geoff said:

A case where a camera will reveal far more than the eye. From my Bortle 6 location I have secured many images with a 4" refractor that show spiral arms in galaxies.

Fair point of course but I will never forget the thrill of seeing the spiral structure and "bridge" of M51 with a 12 inch dob (not mine) and my own eye at my first SGL star party in Herefordshire 🙂

Stuff like that stays with you 😁