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Fluorite Refractors

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#301 edif300

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Posted 24 December 2018 - 07:38 PM

Scott in NC, on 24 Dec 2018 - 7:44 PM, said:

TEC and AP certainly do make lenses. Taking a glass blank (which by itself isn't really useful for anything), then grinding, figuring, and polishing it into a lens, certainly qualifies as "making a lens." If we can't say that those companies make lenses since they didn't make the original glass, then we might as well go to the extreme of saying that Ohara, Hoya, etc. don't make glass since they didn't produce the original raw materials (sand, etc.) from which the glass was made. But doing so would be ridiculous.


LZOS make lenses...

TEC, AP takes the thread at in a middle proccess and then put a “ all made in house “ sticker.

Polishing is not even the most revelant proccess, in fact is one of the most automated (if not one want introducing a zonal error to sell it as high quality aspherized ;-) ), there is not much space into improvement / ingenuity. Lens assembly is more relevant for instance.

Edited by edif300, 24 December 2018 - 07:51 PM.


#302 Alan French

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Posted 24 December 2018 - 08:37 PM

 

No one is making its lenses... All them are outsourcing FPL53, 51, CaF2, FCD01....

It's quite obvious you are talking about making optical glass, not making lenses. Would you claim a contractor was not building houses because the company was buying lumber instead of cutting down trees and making its own?

 

LZOS makes and markets optical glass, but also makes some optics. Making optical glass for refractive optics is an expensive and time consuming detour a relatively small lens maker is unlikely to take. 

 

Clear skies, Alan 


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#303 nicknacknock

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Posted 25 December 2018 - 02:40 AM

Лыткаринский завод оптического стекла or LZOS as we know them, is a company which mostly produces optics for the Russian Military. Any surplus production is diverted to APM Telescopes where it is used along with APM and 3rd party sourced components to provide a final product.

 

AP, TEC - and also SV for some of their products * - obtain the blanks according to their specifications (internal striations / number and size of bubbles etc) and then do the remaining work to create a completed lens assembly, tune it and then create a fully assembled scope out of it.

 

If someone walks in a 5-star Michelin restaurant, do they feel they are not getting their money's worth of a meal because the chef did not cultivate the lettuce, tomatoes, potatoes and all ingredients in a meal? Is the meal not considered made in-house?

 

Semantics can be the death of a conversation. In the end, I want optical performance that approaches perfect optics to as high as possible a degree. For that, I know to which scope makers to turn to.

 

* In order to avoid another SV bashfest, I will note that even Roland of AP recently posted in the Yahoo Group that SV does produce lenses in-house and *gasp*, included SV in the same sentence as AP, TEC and the production of in-house optics. So, let's NOT go down that route and stay on topic.


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#304 edif300

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Posted 25 December 2018 - 03:06 AM

Лыткаринский завод оптического стекла or LZOS as we know them, is a company which mostly produces optics for the Russian Military. Any surplus production is diverted to APM Telescopes where it is used along with APM and 3rd party sourced components to provide a final product.

 

AP, TEC - and also SV for some of their products * - obtain the blanks according to their specifications (internal striations / number and size of bubbles etc) and then do the remaining work to create a completed lens assembly, tune it and then create a fully assembled scope out of it.

 

If someone walks in a 5-star Michelin restaurant, do they feel they are not getting their money's worth of a meal because the chef did not cultivate the lettuce, tomatoes, potatoes and all ingredients in a meal? Is the meal not considered made in-house?

 

Semantics can be the death of a conversation. In the end, I want optical performance that approaches perfect optics to as high as possible a degree. For that, I know to which scope makers to turn to.

 

* In order to avoid another SV bashfest, I will note that even Roland of AP recently posted in the Yahoo Group that SV does produce lenses in-house and *gasp*, included SV in the same sentence as AP, TEC and the production of in-house optics. So, let's NOT go down that route and stay on topic.

We stay in topic while you here are talking about Michelin and tomatoes.

 

Maybe someone are discovering now that making lenses are more complex thing to grinding and polishing. Turning on a machine and wait... Could be included coating in making a lens ? or since maybe Roland doesn’t made coating in house don’t must take it as part of making lens?

 

OK. We follow what Roland said !



#305 Howard Gao

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Posted 25 December 2018 - 06:04 PM

LZOS make lenses...

TEC, AP takes the thread at in a middle proccess and then put a “ all made in house “ sticker.

Polishing is not even the most revelant proccess, in fact is one of the most automated (if not one want introducing a zonal error to sell it as high quality aspherized ;-) ), there is not much space into improvement / ingenuity. Lens assembly is more relevant for instance.

After automatic polishing and coating of lense and simple assemble in a factory the strehl ratio can be better than 0.95. I would consider that high quality.


Edited by Howard Gao, 25 December 2018 - 06:05 PM.

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#306 Jon555

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Posted 04 January 2019 - 12:16 PM

Roland on Fluorite (see the second post):
https://groups.yahoo.../messages/77792

 

"Have I made any fluorite lenses? Yes, we made a number of lenses with fluorite elements from the original 90mm F5 triplet to the 167mm lens used by Ignacio in Argentina (who has taken many superb images with it). All were oil-spaced triplets. Why not airspaced? I am somewhat leery of sending a bunch of very expensive fluorite elements out to a coating lab and have them accidentally ruined in the coating process or broken due to improper handling. If you touch the edge of a fluorite element accidentally to a hard metal surface you may see an instant line develop across the surface, which eventually propagates thru the material and leaves you with two very nice cleaved pieces. When you instead take a freshly polished element and snuggle it between two protective outer elements with a thin oil layer between, you can rest easy and not worry any more. And all internal reflections and centering problems vanish also."

Oh and my Stowaway may ship next week - happy (even though not fluorite) :-)


Edited by Jon555, 04 January 2019 - 12:19 PM.

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#307 SandyHouTex

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Posted 04 January 2019 - 12:46 PM

Roland on Fluorite (see the second post):
https://groups.yahoo.../messages/77792

 

"Have I made any fluorite lenses? Yes, we made a number of lenses with fluorite elements from the original 90mm F5 triplet to the 167mm lens used by Ignacio in Argentina (who has taken many superb images with it). All were oil-spaced triplets. Why not airspaced? I am somewhat leery of sending a bunch of very expensive fluorite elements out to a coating lab and have them accidentally ruined in the coating process or broken due to improper handling. If you touch the edge of a fluorite element accidentally to a hard metal surface you may see an instant line develop across the surface, which eventually propagates thru the material and leaves you with two very nice cleaved pieces. When you instead take a freshly polished element and snuggle it between two protective outer elements with a thin oil layer between, you can rest easy and not worry any more. And all internal reflections and centering problems vanish also."

Oh and my Stowaway may ship next week - happy (even though not fluorite) :-)

Interesting.  Sounds like the voice of experience to me.



#308 25585

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Posted 04 January 2019 - 05:00 PM

Fluorite, so refined, so delicate. flowerred.gif

 

What current scopes have oiled fluorite lenses?



#309 photoracer18

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Posted 04 January 2019 - 05:09 PM

I think all the TEC Fluorite triplets are oil-spaced.
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#310 25585

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Posted 04 January 2019 - 06:24 PM

A very interesting shootout would be between the Baader CaF2, Borg 90mm, both AP Stowaway & Traveller, TV85, a SW Esprit 80 & a Takahashi FC100DC. Any other quality travel scopes, pitting fluoride against other exotic lenses.



#311 mikeDnight

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Posted 05 January 2019 - 02:06 PM

I have to admit there's a special place in my heart for fluorite doublets. It was a Vixen FL102 that started my heart pounding back in January 2003 and its not stopped racing since! Since then I've owned a fabulous FS128, a FS152, numerous non-true fluorite ED's, and now a fantastic FC100DC. Along the way ive used some high end triplets from manufacturers other than Tak, some of which were quite pleasing while others were quite disappointing. I put the differences down to differing glass types, some being warm, some lacklustre. Some made me really have to work hard to see the more intricate detail on planets. Some had obviously suffered at the hands of less than competent owners. Nothing I've yet seen would turn me away from Tak, and particularly Tak's fluorite refractors. The only other scope that could really grip me by the heart strings is still a Tak, and that's the TSA. The TSA is pure Tak ( a stupid statement I know!) but its has such a beautiful lens. My FC100DC has given me jaw dropping colour free views of the Moon at stupid high powers. At X474 the FC is razor sharp with no hint of image breakdown and I'm certain the TSA is equally capable. So, the points I think I'm trying to make are that optical quality and figure is the most important factor in a refractor, glass types are not so important providing the elements are well matched. But then there's the personal equation of wether the observer likes the flavour of a particular lens or lens type. I'm not generally a triplet fan, but if someone were to offer me a TSA102 or 120, I would grab it with both hands and never let go, knowing that its pedigree is one of the world's finest.


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#312 Gavster

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Posted 06 January 2019 - 05:31 AM

A very interesting shootout would be between the Baader CaF2, Borg 90mm, both AP Stowaway & Traveller, TV85, a SW Esprit 80 & a Takahashi FC100DC. Any other quality travel scopes, pitting fluoride against other exotic lenses.

Well one of the things I will be doing in 2019 is comparison between my Baader Travel Companion, Ap Stowaway, Tak fc100df and tv85. Two fluorite, and two other, two doublets, two triplets (one oiled, one air spaced). Covers quite a bit of alternatives.


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#313 rerun

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Posted 06 January 2019 - 05:45 AM

Well one of the things I will be doing in 2019 is comparison between my Baader Travel Companion, Ap Stowaway, Tak fc100df and tv85. Two fluorite, and two other, two doublets, two triplets (one oiled, one air spaced). Covers quite a bit of alternatives.

That will be a very interesting comparison . I can' t wait to read it  .

 

clear skies

 

Markus


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#314 Jon555

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Posted 09 January 2019 - 12:26 PM

...

 

If someone walks in a 5-star Michelin restaurant, do they feel they are not getting their money's worth of a meal because the chef did not cultivate the lettuce, tomatoes, potatoes and all ingredients in a meal? Is the meal not considered made in-house?

 

...

I actually did eat somewhere where they grew all their own greenery... I found a slug crawling across my plate under a pile of it... Almost died laughing as I asked them to have another go... (Well it was fresh: garden -> sink for a rinse -> my plate; so the slug was probably quite fresh and clean...)

 

(Although I do know some people who would have screamed...)


Edited by Jon555, 09 January 2019 - 12:28 PM.


#315 Paul G

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Posted 09 January 2019 - 01:59 PM

I actually did eat somewhere where they grew all their own greenery... I found a slug crawling across my plate under a pile of it... Almost died laughing as I asked them to have another go... (Well it was fresh: garden -> sink for a rinse -> my plate; so the slug was probably quite fresh and clean...)

 

(Although I do know some people who would have screamed...)

That's how people get brain damaged from rat lungworm disease.


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