John

It matches the colour scheme better than an Ethos would

45 minutes ago, Mark at Beaufort said:

Gerry I notice that Lunt now offer a 3.5mm, 5mm, 9mm and the 20mm which is the same range as the Myraid. Having been pleased with the 9mm and 20mm I have been thinking of changing my 4.7mm ES82 for the Myraid 5mm. If the Lunt gets reviews on the same lines as the Ethos range I will have to consider the Lunt 5mm as a possible alternative.

Have you ever used a Pentax XW 5mm Mark ?

After a year of comparing them, I eventually reached the conclusion that the Pentax XW 5mm and 3.5mm were just a wee bit better performers than my Ethos SX 4.7 and 3.7. 

Not 100 degree eyepieces of course but so, so sharp

All the 100 degree eyepieces I've used seem to offer slight improvements in performance terms (not just the FoV) over the 82 degree eyepieces from the same brand.

When a 100 degree range comes along that is consistently better than the Ethos then I'll think about changing. Meanwhile .......

I'll be interested to hear your views Gerry.

My info is that optically the Lunts are the same as the Skywatcher Myriads and their clones. The 20mm Myriad was a very nice hyper wide eyepiece when I compared it with my Ethos 21.

If I'd wanted to save lots of £'s in return for some very small compromises in performance (very small) then my Ethos 21 might have been in danger.

The Lunts have the soft foldable eye cup which I prefer over the hard twist up / down style of the Myriad.

2 minutes ago, Gavster said:

John, I agree with you that the focus on holiday should be spending time with our families and taking a break from normal life. I'd only take some telescope stuff when th me if I thought there was the likelihood of seeing objects that I either couldn't see or were low in the sky in the UK. I was in Barbados earlier this year and from there some Southern Hemisphere objects are visible which was a real incentive to take some gear with me.

Makes sense Gavin. I was in Florida a couple of weeks back and we are in Costa Rica in September but I'm resisting the tempation. Wildlife seems to take centre stage on holiday which both my wife and I are interested in

Some very nice and interesting portable gear in these posts

I don't take astro stuff with me on holiday apart from small binoculars and those get used mostly for wildlife / birding.

I find that it's good to have a break from the hobby from time to time and I appreciate it when I get back

Hello and welcome to the forum.

Which direction was the object and how far from the horizon was it ? A location, date and time (local) of the observation would help as well.

Sirius does not actually blink but can appear to scintillate because, from northern latitudes, it is quite low down in the sky and we observe it through lots of atmosphere.

Some excellent items in there - room for more too !

7 minutes ago, iPeace said:

Yep. An AZ11. 

There might be something in that

5 minutes ago, Stu said:

Having seen and used a T-Rex last night with the TEC140, I know what the fuss is about now. Lovely, solid and with slo mo controls is could actually get on with!

Unfortunately I believe they won't be making any more T-Rex's

I can't imagine that they come on the used market much.

16 minutes ago, iPeace said:

...Anyone considering it should keep in mind that it's basically a reworked GM8 - in other words, think of which EQ  mount you would choose for your scope, a GM8 or a GM11. If the GM8 would suffice, then this is your alt-az mount. If you would really need the GM11 for your scope, then adjust your expectations accordingly. Also factor in your own personal fussiness with regard to how solidly mounted the scope should be; what's fine for some will be marginal or even intolerable for others.

If your Ercole or Sabre or SkyTee is getting it done for you, but you want slo-mo or perhaps less of what the SkyTee occasionally seems to offer, the AZ8 is hard to ignore.

 

Thats very useful "rule of thumb" advice Mike

My 130mm F/9 triplet is into GM11 territory I reckon

I still think there is a niche for a manual alt-az that is somewhere between the Ercole / Skytee II / AZ8 and the DM6 / APM AzMaxLoad / T-Rex in capacity terms. 

The GSO mirrors (of the ones I've tried) seem to be of a similar optical quality to Skywatchers ie: pretty good for mass produced.

Zhumell are actually made by GSO and are the same as the Revelation dobsonians sold in the UK and the Telescope Services (TS) dobsonians sold in Germany. GSO also make the Meade Lightbridge dobsonians and the Zhumell ones will have the same mirrors and mirror cells in them.

GSO and Synta (who make Skywatcher, Celestron and quite a few Orion (USA) scopes are different companies I believe.

Zhumell dobsonians are very popular in the USA and the "Cloudynights" forum is full of posts on them. The brand are rarely seen on this side of the pond though.

I've owned a Meade Lightbridge 12" and a Revelation 8" and they were pretty decent scopes. The collimation springs on the 12" GSO made dobs have a reputation for being a little weak and a common upgrade is to replace these springs with more robust ones.

Looks a bit like a chess game Dave

I reckon its the rise in popularity of imaging that has driven the industry to produce faster apo refractors. Thats why scopes such as the Tak FC-100 DL fluorite doublet and the TMB / LZOS 130 triplet F/9.2 are different - they are squarely aimed at the visual astronomer.

The original Tak FC100N was a F/10 fluorite doublet. Nikon and Pentax used to produce similar "slow" ED doublets some way back.

1 hour ago, mikeDnight said:

Hi John,

My late friend Phil was obsessed with comparing spot diagrams of various designs of telescope. He spent a lot of his time over many years designing many different kinds of telescope. From what I remember about the spot diagrams he showed me, if a telescope keeps its natural aberrations within the Airy disk, it is essentially perfect. Most telescopes come nowhere near this kind of perfection, though Apo refractors tend to be among the best. Often the aberrations between similar scopes such as the DL and DC, though being noticeably different on paper, still come close to, or within the confines of the Airy disk and so both scopes will offer essentially the same level of performance, or at least it would take a very expert eye to notice any real difference in image quality. For a 6" achromat to give a perfect image it would need to have a F ratio of around F25, yet at F15 it performs stunningly, so it illustrates how forgiving the visual view is. SCT's produce very poor spot diagrams and this is quite noticeable in the star image produced, where the star never quite seems to snap into focus, yet the SCT remains popular. As you pointed out, focal length does play a part. Short F ratio Newtonians suffer from numerous destructive aberrations outside the Airy disk, where as, long focal length Newts have very tightly constrained aberrations and deliver near perfect images. It seems to me that we're all so easily distracted by graphs, spot diagrams and Strehl that we forget the most important factor which Gavin touched on when he said he's "Loving" his AP130. ❤??

Mike

Interesting Mike and I'm sure it holds good

Of my 4 refractors, I'm fondest of the Vixen and the Skywatcher simply because I've owned them a long time. They and the 12" (especially that scope) are the ones that have contributed most to my enjoyment of the hobby because they have been with me longer, of course.

While the images through the Tak DL and the TMB / LZOS 130 F/9 are technically the best I've ever seen for those apertures, they have yet to become "friends" in the way the others have. These scopes will show me things that I have already seen slightly better than I have seen them before. The 12" dob is still capable of showing me new things. Gotta respect that

None of this is surprising though - I've been in the hobby too long to nurture unrealstic expectations of kit these days

How am I going to get some new "kicks" ? - subject for another thread I think.

Sorry to rabbit on in your AP 130 thread Gavin. You have wonderful scopes mate - treasure them

15 hours ago, Highburymark said:

Thanks John. That's cleared that up then. ?

Not really, my FC-100DL is rubbish

16 minutes ago, Highburymark said:

Just checked - and yes, the DL is identical to the DF/DC bar the focal length. 

I think the DL has a slightly tighter spot diagram, whatever that means. Probably more to do with the different focal ratio rather than differnt figuring quality though.

The official blurb at the launch said this (Google translated from the original Japanese, so blame that !):

"In recent years of refraction telescope, but Photo visual system short focus apochromat has become the mainstream, it is the emergence of these and differing length personality focus two ball fluorite apochromatic telescope FC-100DL.
FC-100DL in the FC type which arranged the street flow light lens of the name behind, worthy of long focal refraction of f / 9.0, chromatic aberration, you get high spherical aberration less contrast image. Specifically, halo is approximately 40% reduction of the g-line against FC-100D of f / 7.3 (purple), and has realized the 97.5 percent of about 4% increase in the Strehl ratio that indicates the high magnification performance. (Data calculated)
This aberration data is almost the same number as the three pieces ball apochromat, coma is coupled with stable image plane of the zero, I think that you understand that it is a telescope that has a high-eye viewing performance."

It's funny with scopes. Last year I bought 2 "dream" scopes, the Tak FC-100DL and the TMB / LZOS 130 F/9. They are both superb instruments and undoubtely the best scopes of their respective apertures that I've ever viewed though and arguably in the top few ever made at those apertures for amateur use.

You would have thought that the old, slightly scruffy gold tubed ED120 Skywatcher would have had it's marching orders ?. But no, I keep coming back to the Skywatcher of all things. I guess that it's the whole package that is "right" with that one which includes size, weight, ease of mounting, cool down, ruggedness as well as optical ability way above it's price band. Still trying to figure it out .....

You would have thought that the additional 10mm might have given the edge to the TEC140 on double stars ?

From what I've read, both objectives are of just about the finest optical quality that is available to the amateur

I suspect you are going to have to compare the two night after night on a really wide array of very challenging targets to reveal any meaningful differences, apart from the aperture.

Additional aperture usually gives a better view of globular clusters. Whether 10mm is enough to see much difference will be interesting to find out

The 22mm T4 Nagler is a really lovely eyepiece. I swapped mine for a T5 20mm but I should have kept the 22 T4 I think

Nice 1st light report Gavin

Funny how these scopes we dream about, while being excellent, still have their quirks when you look at them critically

I have a Feathertouch on the TMB / LZOS 130 and it's superb.

No surprise that the AP 130 delivers a better split of Epsilon Lyrae than the Tak 100 DL does but, IMHO, the Tak is still really amazing for a 3.9 inch

I guess cool down comparisons are about oill spaced vs air spaced ?

All very good stuff - look forward to more reports

I've only ever seen them when examining intra and extra focal star images and then only as very slight "nicks" at the edge of the diffraction ring pattern.

If you view a star that happens to have a flat surface running somewhere roughly between your scope and the target (eg: phone wire etc) then you do get diffraction spikes of sorts which can be rather disconcerting !

Vixen must have, or have had, some sort of relationship with Synta I think. Certainly some of their scopes have been made by them. I'm thinking of the 100 and 80 SF refractors in particular.

I don't know if this extends to other Vixen lines as well