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Tec140ED used vs TSA 120 new?


Fedele
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2 hours ago, John said:

I was using 600x on tight double stars and to spot Triton last night with my LZOS 130. 240x seemed the best for Jupiter and 300x did well on Saturn. Your LZOS (and @Stu's) are very similar optical quality I think. If you get the seeing, pump up the power ! :thumbright:

That's amazing performance, John! At 600x you must have been almost constantly turning those big slow mo's!😱😂

I can't get above about 468x with my eyepiece/barlow combinations, and tbh I don't think my floaters would allow me to view many objects,  comfortably, much above 300x.

But my FS128 manual encourages owners to go up to 100x per inch of aperture on nights of very good seeing..

I have absolutely no doubt that your Lzos lens is superb..Russian optics are renowned for their quality, and rightly so. I've owned a few Intes/Lomo 6" Maks and each of them was optically wonderful.

Dave

 

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This must be the first thread I’ve encountered anywhere ( though I’ve not dug into CN lately) where the quality of the TEC140 is being picked at 😂. I’ve owned #165 with the FT focuser from new.  It is an absolutely marvellous scope. Es Reid tested mine and confirmed this.  I don’t know if the fluorite version is any better visually - I’m at a loss to see how it could be.  Comparing fairly similar competitive scopes is never likely to be an objective exercise because user tastes differ, eyepieces perform differently in different scopes, ergonomics, feel, etc etc. Too many variables personal and instrument related. It beggars belief (if you’ve spent time with one) to hear the TEC140 described as ‘lacking’ something 🙄. That said, it is ‘only’ a 5.5 inch scope and, beautiful though its images are, it’s inevitably outperformed in terms of resolution by decent bigger scopes. Given that it’s optical quality is pretty much as good as it can get (see Chris Lord’s analysis/review), I personally take evaluations of smaller telescopes outperforming it visually with a pinch of salt.  Other factors than optical have to be involved.  And, by the way, where are all those leaky oil-spaced triplets dripping all over the place?!  😂  

 

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5 minutes ago, kirkster501 said:

I don't think one has arrived this year so far Jeremy....🤨

..not here in Lincolnshire, it hasn't.

Ironically Iast night was a decent night (apart from the wretched waning moon, which is getting higher in the sky each night), and I was able to see half a dozen distinct belts etc on Jupiter..but I then saw a post on SGL and in the 10 minutes it took me to reply, looking down at my phone, the sky had completely clouded over - and that was it for the night!

Dave

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3 hours ago, John said:

I was using 600x on tight double stars and to spot Triton last night with my LZOS 130. 240x seemed the best for Jupiter and 300x did well on Saturn. Your LZOS (and @Stu's) are very similar optical quality I think. If you get the seeing, pump up the power ! :thumbright:

Hope you get some good sessions in with the scope soon :icon_biggrin:

A question for TSA 120 owners if I may: We know that Canon Optron make the objectives for the Tak Fluorite doublets. Do Tak make their triplets (such as the TSA) themselves or is a third party optical house involved for those ?

Edit: Just found the answer from Roger Vine's review of the TSA 102: "The TSA-102’s lens is an air-spaced triplet made in Japan by Canon/Optron"

 

 

 

From what I've read Canon Optron have been Takahasi's supplier of lenses since at least the late 70s and that it was they who approached Tak about making a Fraunhofer fluorite scope after they'd developed a method for hard coating the stuff. Apparently when they were testing the prototype lens they went as far as scrubbing the surface with a wire brush and it did nothing! There was a suggestion of using this in the marketing to show how durable the coatings were but it was quickly shot down as they didn't want to encourage people to do stupid stuff like that.

Lens design is done in-house, as is manufacture of lens cells and the grinding and polishing of mirrors.

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4 minutes ago, Andrew_B said:

....Lens design is done in-house, as is manufacture of lens cells and the grinding and polishing of mirrors.

Do they make the glass as well ?. I believe they do with Fluorite but how about the glasses used in the TSA and TOA refractors ?

 

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2 hours ago, ollypenrice said:

Life's too short to read all of a thread like that but by the end of page one I hadn't found a leaking TEC...

Olly

I've read of it happening with the occasional older Astro-Physics scope but it seems to be one of those very rare issues that if it does occur then you're going to hear about it.

Bacterial growth and mould on lenses of any type is more common but often that's a result of people putting scopes and camera gear in cold and damp attics or leaving thing for long periods in sheds and garages. My stuff stays in the front of the house where it's warmest and driest.

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1 hour ago, F15Rules said:

That's amazing performance, John! At 600x you must have been almost constantly turning those big slow mo's!😱😂

 

 

Indeed - 50 degree AFoV as well with the Nagler zoom :rolleyes2:

Fortunately the slow motion controls of the T-Rex are very smooth and create no vibrations in use. It's not exactly a relaxing pastime though :grin:

 

 

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4 minutes ago, John said:

Do they make the glass as well ?. I believe they do with Fluorite but how about the glasses used in the TSA and TOA refractors ?

 

Good question. Optron is one of a handful of fluorite manufacturers - the main use for the stuff is industrial optics and in photolithography machines in particular which is why it's available as extremely high quality blanks far larger than is available with comparable optical glasses. Blanks of sufficient quality for telescope optics are made up to 440mm - can you imagine what one of them would cost 😲

I think the TSA uses FPL-53 and the TOA models definitely do so presumably Canon would be buying the blanks for those from Ohara. I wouldn't think they'd make the mating glass in-house either so that probably comes from Ohara or Schott, but I could be wrong because in one of Canon's videos about their lens making they appear to be producing glass from the raw materials.

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1 hour ago, Andrew_B said:

I think the TSA uses FPL-53 and the TOA models definitely do so presumably Canon would be buying the blanks for those from Ohara. I wouldn't think they'd make the mating glass in-house either so that probably comes from Ohara or Schott, but I could be wrong because in one of Canon's videos about their lens making they appear to be producing glass from the raw materials.

I suspect Japan has one foundry for the glass, the furnaces have Palladium walls to produce FPL type glass. These foundries use to exist in the US until the bean counter's sold them off as the furnace was worth more than the business it supported. The only other foundries will be in Russia and China.

Edited by Deadlake
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1 hour ago, Deadlake said:

I suspect Japan has one foundry for the glass, the furnaces have Palladium walls to produce FPL type glass. These foundries use to exist in the US until the bean counter's sold them off as the furnace was worth more than the business it supported. The only other foundries will be in Russia and China.

I remember reading about that. Companies like Kodak and Bausch and Lomb had these glass furnaces with solid palladium or platinum linings, crucibles, and stirrers and when catalytic converters started being added to every car the demand for these precious metals went through the roof and the price rose accordingly so they scrapped the furnaced and sold the metal. Staggeringly short sighted.

Presumably all the glass for US-made high end optics is sourced from overseas then now? The optics divisions of these companies still exist, just under different names and often catering to defence clients. Leica Canada is now Raytheon ELCAN and Kodak divested that part of their business as Itek which is now part of L3Harris - they're the folks who make the optics for spy satellites and have done since the 60s.

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12 hours ago, jetstream said:

I brought this up because @Fedele lives in Italy I believe and might possibly have extremely high temps at times which might impact an expensive oil spaced refractor. Some might not find that link interesting but some just might, given the cost of these telescopes, IMHO.

That's worth bringing up, certainly. However, I'm in the south of France with outside temperatures occasionally reaching 40C with mid-thirties commonplace.  Both the TEC 140s based here live permanently in the observatories where temperatures go far higher than that in the daytime and winter temperatures go down to the minus teens routinely. (There is no possibility of dismantling the rigs since they are part of an dual imaging installation which takes days to  fettle.) We haven't had a problem.

Olly

Edited by ollypenrice
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14 hours ago, ollypenrice said:

If it leaks. But it doesn't. And bacterial growth can affect air spaced lenses, too...

Olly

My comment was aimed at oil spaced systems and not at the TEC140 specifically.

I have read reports on CN where owners had to return oil spaced cells due to the oil going milky and also for leaks. To be fair these were older AP scopes that were brought back to their original condition by Roland and his team.

TEC may have a different method of manufacturing their scopes or they may not be old enough yet to fail - but it could be a possibility.

There was certainly enough evidence to deter me from buying an oil based system so my money went the air spaced way.

In my opinion it is a factor that the OP should take into account which is why I mentioned it.

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On 24/09/2021 at 15:28, dweller25 said:

I would go for an air spaced scope as oil gets messy when it leaks 🥴

Worth pointing out that the TEC oil spaced design only has a few drops of oil between the lens elements, not half a pint or anything like that.

Theres nothing much really to leak and the lens cell is designed optimally for this optical design, which is tried and tested over 20 years.

TEC made around 750  140mm units an i bet the fluorite versions are over 100 strong now.

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26 minutes ago, Deadlake said:

Well for air spaced designs like a TOA-130 need to get the liquid nitrogen cryo storage out to get it down to temperature, pro's and cons as usual... 

Don't forget that you also need to keep it in an atmosphere that's been completely purged of oxygen and water vapour to prevent mould and bacterial growth inside the lens cell.

It's a wonder any of these pieces of junk work at all. 😆

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20 hours ago, Space Hopper said:

TEC made around 750  140mm units an i bet the fluorite versions are over 100 strong now.

750 ?

Wow !. I think the total number of 130 LZOS F/9.2's made since 2006 is less than 150 units. I guess they are the preserve of the visual observers and of little interest to imagers though.

 

 

 

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1 hour ago, Space Hopper said:

Quite the contrary as Olly will tell you.....

I was referring to the 130 F/9.2's being of little interest to imagers. The TEC 140's certainly are.

The needs of imagers drives the refractor market far more than those of visual observers.

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1 minute ago, JeremyS said:

True John. But fortunately they are not overriding, witness the Tak FC 100DL and FOA 60Q 👍🏻

Yes, there are the occasional "outliers" from time to time :smiley:

The chinese made 102mm F/11 ED doublets came as a bit of a surprise to most I seem to recall.

 

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