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William Optics FLT 90

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#1 Phishin_phool

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Posted 25 January 2021 - 12:20 AM

Does anybody have any info when this might be available or know if anybody is taking preorders.

 

https://www.youtube....eature=youtu.be

 

 



#2 Sedim

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Posted 25 January 2021 - 01:43 AM

Looks like a new 91mm triplet f/5.9 for around $2000.
Here is a link: https://www.cyclopso...t-91-f-5-9-apo/

#3 sg6

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Posted 25 January 2021 - 03:18 AM

Looks nice, I actually have no desire for one, maybe a bit strange for me, but no great attraction.

 

One maybe odd question: Wonder why they called it FLT? Would have thought they would have added it on to the GT series in name.



#4 Phishin_phool

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Posted 25 January 2021 - 07:45 AM

Looks nice, I actually have no desire for one, maybe a bit strange for me, but no great attraction.

One maybe odd question: Wonder why they called it FLT? Would have thought they would have added it on to the GT series in name.


The FLT line is an upgrade to the GT line. The Fluorite glass / lens system is of higher caliber and greater Strehl #

#5 imtl

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Posted 25 January 2021 - 08:34 AM

Moved from BDI.



#6 Cometeer

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Posted 25 January 2021 - 01:08 PM

The FLT line is an upgrade to the GT line. The Fluorite glass / lens system is of higher caliber and greater Strehl #


The FLT line does not actually use flourite. It has always used fpl-53 glass.

#7 Phishin_phool

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Posted 26 January 2021 - 12:40 AM

The FLT line does not actually use flourite. It has always used fpl-53 glass.

My mistake - thank you for the correction - I do not want to pass on bad info - I got that from Agena Astro's page

 

 

6. Fluorostar Refractors

alt tag
Figure 5 – A Fluorostar 132mm refractor telescopes in red trim. Image credit: William Optics.
William Optics offers another model of apochromatic triplet refractor, the Fluorostar. It is similar to the Gran Turismo series, but at present it comes in only a single aperture (132mm) and focal ratio (f/7). These are premium instruments primarily aimed at astrophotographers, but they can also be used for visual observations. The Fluorostar refractor includes a fluorite glass element in the objective lens to further reduce chromatic aberration relative to the Gran Turismo series. Because of its larger size, the FLT132 comes with a heavier mounting plate.

The FLT132 fluorostar refractor requires the William Optics Flattener 8 field flattener/0.72x focal reducer for astrophotography with larger-sensor cameras. The FLT132 is also offered with a FeatherTouch focuser upgrade.

BEST FOR:
- Astrophotography (with flattener reducer, sold separately)
- Visual observation of deep sky and lunar/planetary

LIMITATIONS:
- Heavier and more expensive relative to doublet refractors

PRODUCT LINKS:
- William Optics Fluorostar Triplet ED Refractors



#8 Cometeer

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Posted 26 January 2021 - 01:25 AM

My mistake - thank you for the correction - I do not want to pass on bad info - I got that from Agena Astro's page

That’s interesting. WO’s own description has no mention of flourite glass. They only mention fpl-53. https://williamoptic.../fluorostar-132 and https://williamoptic...rostar-132-2020
 

To my knowledge, WO only released one flourite scope ever and that was an 80mm iirc. 


Edited by Cometeer, 26 January 2021 - 01:26 AM.


#9 Phishin_phool

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Posted 26 January 2021 - 06:46 AM

After seeing your post I also looked at the WO  and see them acknowledge FLP53 glass - do not want to mischaracterize anything (just wanted people to know where I had got that from). It appears that hey are using Lanthanum in FLT Lenses - (from Wo website)

 

https://williamoptic...tented-included



#10 photoracer18

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Posted 26 January 2021 - 08:27 PM

Actually at least the first FLT scope used OK-4. All FLT means is fluorite doped glass which all of the OHARA lenses back to and including the FPL-51 do. However no one is going to mistake FPL-51 for CaF2.



#11 javawolfpack

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Posted 30 January 2021 - 04:40 PM

WO indicated "Start shipping to worldwide dealers around Feb 18" in regards to the FLT91 on their Facebook page 1 day ago. Also more technical details on the scope in a pinned post. 



#12 AZ49

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Posted 27 February 2021 - 06:01 PM

Just placed an order for one. Coming next week. I feel 91mm is a nice sweet spot. Hopefully it doesn’t disappoint. 




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