John

5 minutes ago, Stu said:

Looks very nice. Which glass type is used that’s equivalent to FPL-53? 

The FLO description says that is is the equivalent of ohara S-FPL-53 but does not specify which glass is used for the ED element. Hoya FCD100 is one that would fit the bill I think.

14 minutes ago, Pixies said:

That's the finder for the EQ "Polaris" variant of the old Vixen refractors. It's a completely different type of design. There is no actual finder tube within the holder, it's all one piece. The alt/az "Custom" had the more standard finder. I have a couple in various states of repair. I'll try and dig them out for pictures, later.

Many of the Vixen refractors sold in the UK had separate finder mounts added to the tube and the integral focuser based finder mounting system (such as the one pictured by @Froeng) were removed / blanked off. The ones sold by Astro Systems back in the 1980's for example have a finder mounting foot a little way up the main tube and this approach was used for the "Custom" models as well as the SP achromats and fluorites. 

Maybe having the finder mount integral with the focuser was favoured by Japanese / European customers ?

The spec looks similar to the Technosky 125mm that the late (and much missed) @johninderby had:

Tecnosky 125/975 F7.8 FPL-53 Doublet APO - First Look - Discussions - Scopes / Whole setups - Stargazers Lounge

It is a very interesting scope at a very interesting price.

Not sure that carbon fibre has any advantages for the visual observer though ?

Unless it has been treated to behave like Kruppax 50 that is !

It's an amazing instrument and it looks to be really well thought through and engineered 👍

If you really want to part with it, the UK Astro Buy & Sell website might be worth a try. It is generally a respected place to buy & sell astro equipment:

U.K. Astronomy Buy & Sell (astrobuysell.com)

Now that is one amazing and beautiful refractor 😁

It is always interesting to hear and see what gear others are using and how they are using it - thanks for posting this Dave 👍

I'm thinking of using my  Baader Zeiss T2 in 2 inch mode so it is useful to see how you approach that.

The Pentax 8-24 zoom is quite a lump isn't it 🙂 

I'm a little surprised that this topic has not attracted more responses 

My Vixen ED102SS F/6.5 is a great little scope but it's optical figure is not quite as good as that of my Tak FC100-DL. The star tests from the Vixen are excellent with perfectly concentric diffraction rings either side of focus but at sharp focus the 1st diffraction ring around moderately bright stars is slightly more prominent than the Tak's -  I think that means that the Vixen objective probably has a touch of spherical aberration.

However, when observing, the slightly more obvious diffraction ring can actually lead to aesthetically pleasing results when observing binary stars such as Castor, Algieba, Gamma Virgonis and Epsilon Lyrae. The pairs of stars, being roughly equal in brightness with these targets, have a delicate and thin figure of 8 shaped fine line of light encompassing them, like this:

With the Tak, on the same targets, the diffraction rings are either invisible or so thin that they are not obvious. 

I actually enjoy this "slightly-less-than-perfect" presentation of these brighter star pairings 🙂

With uneven pairs the effect can be like a "diamond ring" with the fainter star appearing to sit on the edge of the diffraction ring of the brighter component. Again, that can be very attractive.

Where the stronger diffraction ring is less helpful is with close pairs of highly uneven brightness (eg: Zeta Herculis) where the fainter component star can be partially masked by the diffraction ring around the brighter one. With such stars, getting the positive split is easier with the Tak.

On occasions in the past I have described Zeta Herculis diffraction ring as looking like a thin snake that has swallowed a tennis ball with the dimmer secondary star seemingly embedded within it !

So it depends on how exacting my targets are I guess but sometimes I do appreciate beautiful imperfection at the eyepiece 🙂

19 hours ago, Leo S said:

I just came across another example, by complete chance, while googling the ""Atacama Desert" for another thread!

Around 12,000 years ago there is very strong evidence for an impact (air burst) in the region, but once again, no crater.

From the article:

"There may be lots of these blast scars out there, but until now we haven't had enough evidence to make us believe they were truly related to airburst events," Schultz said. "I think this site provides a template to help refine our impact models and will help to identify similar sites elsewhere."

 

That is interesting. The timing of the fall of the Vaca Muerta meteorite has been put at somewhere between 2,500 and 4,500 years ago. It is reckoned that nearly 4,000kg of material from that meteorite has been found over the years.

The Vaca Muerta fall did create some small craters:

15 minutes ago, Leo S said:

There are plenty of places left to go for pristine dark sky, but if the distance didn't matter I think I head for the Atacama Desert in Chile. Pristine skies at night, and also lots of flat featureless terrain, making it a meteorite hunter's paradise in the day.

I'd love to go but when I showed my other half a photo of meteorite hunting in the Atacama, she was not too keen 😔

I do have a small slice of the Vacua Muerta meteorite so I guess that will have to do 🙄

1 minute ago, saac said:

What about Woolsthrope Manor, I'd love to visit it. There is more than enough association with astronomy I think to justify it for consideration.

https://www.nationaltrust.org.uk/visit/nottinghamshire-lincolnshire/woolsthorpe-manor

Jim 

We visited Woolsthorpe Manor about 5 years ago. Very interesting place. Great to stand in the actual room where Newton first experimented with light and prisms and to see the famous apple tree 🙂

1 minute ago, Franklin said:

..... Observing these areas under different illumination shows no trace of these "Tricks of the light".

Rather like the infamous "face" on mars ?

I snapped this a couple of years back. The orientation is as our eyes see it - the "L" appears backwards through a scope !

My astro society were recently gifted this amazing setup. We are currently installing it at our observatory in a special roll-off type housing. The chair is motorised and controlled with a joystick. The instrument (which we were also given) is the Fuji Meibo 25 x 150mm binoculars - which are huge !!! 😮

Hopefully it will all be up and running for the return of darker nights in the Autumn. I'm certainly looking forward to having a go 😁

While "as dark as possible" is my motto when deep sky observing, for planetary observing it is not the case, quite possibly the opposite. 

It all started with Algieba (Gamma Leonis) for me. My little 60mm refractor made it look so beautiful 🙂

My skies are not bad here but I always throw a few favourite double stars into an observing session 👍

The Star Splitters website is one of my favourites - real enthusiasts and wonderful descriptions of their observing adventures:

Star-Splitters (wordpress.com)

23 hours ago, John said:

Again tonight with my 100mm. Perhaps a touch fainter again - magnitude 11.9 / 12.0 maybe ?

Now tonight with my 102mm refractor it looks a touch brighter - my estimate this evening is magnitude 11.5. I doubt that the additional 2mm of aperture is having that much impact ! 😁

It might just be a more transparent sky tonight.

I've just been looking at this comet with my 102mm refractor. Quite hard to tease out against the summer sky. I found that I needed 80x magnification to show it more clearly. Still around magnitude 10 I would think.

4 hours ago, JeremyS said:

Better not try a Tak FOA 60Q then, John! 🤣

No need Jeremy 😉

2 hours ago, Mike Q said:

Last night was the first really decent night we have had in a long time and I spent it doing outreach with the club........  All in all it was a satisfying night even though i didnt actually get to do much looking.  

That is the thing about outreach events - often your own observing has to take a back seat !

It's good fun though and the reaction of others seeing stuff, probably for the first time, is really rewarding 🙂

1 hour ago, F15Rules said:

The Lzos 130 looks great on the GPDX John..👍. How does the mount handle it? I've had my FS128 on one in the past, and it worked quite well: but the  8.1 Tak is only about 8.5kg including finder, diagonal etc, whereas I'd imagine the Lzos F9(Triplet?) is a fair bit heavier? The sturdy wooden tripod will help stability of course..is that one a Tal tripod?  Certainly looks like one😊.

I remember holding an Lzos of c106mm/F6 spec I think it was, when I visited someone to view a different scope some years ago, and I was amazed at how solid and heavy the Russian scope was.

Thanks for sharing.

Dave

Hi Dave and thanks for the comments.

The tripod is my Berlebach Uni 28. It's an older one and the wood tone has "matured" from the pale original colour. 

The GPDX was OK with the F/9.2 130mm triplet on board but, similar to the HEQ5 and Celestron AVX that I tried the scope on for a while, it didn't quite hold it steady enough to enable the high powers that the optics are capable of to be used to their best advantage. The optical tube assembly, including tube rings, losmandy plate, finder and diagonal weighs 9.4kg. Not too bad for a triplet but, yes, longer and heaver than the FS128. Mine has a Kruppax 50 tube which I think helps keep the weight down. Some of the earlier TMB/LZOS tripets used a distinctive white / polished alloy finish which looks excellent but they are heavy scopes for their aperture.

My breakthrough in mounting my TMB/LZOS 130 came when a T-Rex alt-azimuth, rather unusually, came up for sale. The T-Rex is an amazingly capable mount and handles the 130 F/9.2 really effortlessly even at 400x plus, which the scope is easily capable of supporting, under decent seeing.

The alternative to the T-Rex would have been a Rowan AZ100 I think.

2 hours ago, Stu said:

This one?

Yes, that's the one. Bit of a stretch to call it an "X" I suppose but it's fun anyway !

Lovely 😁

The 2nd X is showing to the S of the main X I think. It's a more elongated X 🙂

Just going to take a peek with my little Vixen 4 inch. Thanks for the "heads up" @Stu 🙂

1 hour ago, Franklin said:

This may not be new but it's the first time I've seen it.

Thumbs up for the SD103S.

Vixen SD103S Review (scopeviews.co.uk)

Thanks for posting that 🙂

It was interesting that Vixen moved from the two model ED102S / ED102SS at F/9 and F/6.5 respectively line up to a single model SD102S at F/7.7. I understood this change was due to problems with the lead content of the non-ED element used in the ED102's forcing a re-design of the doublet objective resulting in a slight clear aperture increase and the mid-range focal ratio of F/7.7.

Vixen didn't state the ED glass type used in the ED102's although I was fairly sure it had to be FPl-53 from the CA control they achieved in even the faster F/6.5 version, the SS model.

My own ED102SS dates from around 2000 and I've owned it for 16 years. It's a great "all rounder" 🙂

I'm going to have a look at the Moon and Venus with it right now in fact !