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80mm ED f/10 FPL-53 & Lanthanum

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#26 johninderby-uk

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Posted 03 February 2020 - 04:47 AM

Bottom line is it fills a gap in my scope collection very nicely. It is what I want. Prefer the increased depth of field the longer focal length gives. 

 

I’ve always said buy the scope you want and if somebody else doesn’t agree with your choice. Well tough it’s your money not theirs. 


Edited by johninderby-uk, 03 February 2020 - 06:13 AM.

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#27 25585

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Posted 03 February 2020 - 06:07 AM

I asked what version of this Long Perng scope is this to Starfield and Ontario telescope but they ignored it.  So I chose not to buy it at this time. 

 

I gather it is the A model.

 

Your reasoning makes completely sense and I still might pull the trigger sometime on this one because I really like the concept.

I emailed First Light Optics, & had a reply. The optics are the same, FPL-53 & Lanthanum, for both Crayford and r&p focuser models. Rack & pinion is "heavier duty", so FLO opted to stock that one.     


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#28 Riccardo_italy

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Posted 03 February 2020 - 07:39 AM

Also it's interesting to see claims of a dual ED triplet lens design on the other models like the Stellamira 104mm F6 (link here https://www.firstlig...-telescope.html )

 

I've never seen a triplet with an extra ED element before, and I wonder what that brings when it's possible to get apochromatic performance with a triplet lens with just one extra high dispersion element.

Tak TOA 150.....


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#29 AstroFalcon

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Posted 03 February 2020 - 08:41 AM

I too emailed First Light Optics, and the scope weighs 4.1 kg including the tube rings. 


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#30 Bennevis

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Posted 03 February 2020 - 08:55 AM

Tak TOA 150.....

I didn't know thanks Riccardo - so I guess the colour correction must be better than a triplet with one FPL53 element, to make the design justifiable.

 

It would be good to see some evidence of this and also information on what the elements are composed of.

 

I would be very interested to know the Abbe number's of the each element


Edited by Bennevis, 03 February 2020 - 08:57 AM.


#31 Bennevis

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Posted 03 February 2020 - 08:58 AM

I emailed First Light Optics, & had a reply. The optics are the same, FPL-53 & Lanthanum, for both Crayford and r&p focuser models. Rack & pinion is "heavier duty", so FLO opted to stock that one.     

Is that both FLP53 elements or one did they say?



#32 johninderby-uk

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Posted 03 February 2020 - 09:03 AM

They say:

 

ED APO Doublet optics including 1x ED APO FPL-53 lens and 1x Lanthanum lens

 

Triplet optics with 1x FPL-53 element, 1x FPL-51 element and 1x Lanthanum element


Edited by johninderby-uk, 03 February 2020 - 09:04 AM.


#33 25585

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Posted 03 February 2020 - 12:59 PM

Both TOAs 130 & 150 are double ED.

 

The TS Sharpstar 140mm us double ED, but TS don't say what glass. 



#34 Gregory Gross

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Posted 03 February 2020 - 01:13 PM

I too emailed First Light Optics, and the scope weighs 4.1 kg including the tube rings.

In a thread entitled "Sky-Watcher EvoStar 100ED Weight" that I started in December 2018, user db2005 reported that the SW 100ED weighed in at 3.640 kg on a digital kitchen scale.
 
At 4.1 kg, this 80mm f/10 scope and rings that Long Perng is producing must be built like a tank. I have to confess that, after eyeballing the images of this scope, I would not have expected an 80mm scope to weigh in at 9 pounds, though I also confess to not having much meaningful experience with handling refractors.



#35 johninderby-uk

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Posted 03 February 2020 - 01:19 PM

My scope is arriving tomorrow so will post some photos and will check the weight etc.


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#36 Gregory Gross

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Posted 03 February 2020 - 03:38 PM

My scope is arriving tomorrow so will post some photos and will check the weight etc.

Very much appreciated! When you check the weight, would you be wiling to indicate what accessories (rings, dust caps, etc.) were on the scope?



#37 johninderby-uk

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Posted 03 February 2020 - 03:42 PM

Will do.

 

Does include the tube rings and a carry handle and has twist lock clamps on the focuser ( both the 2” and 1.25” adapter).


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#38 Gregory Gross

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Posted 03 February 2020 - 03:59 PM

I gotta say this scope looks very well accessorized and has an overall solid and well-made look. A few notches above the typical mass-produced scope. Just judging on appearances, it looks like Long Perng did a great job with this one. I look forward to learning your thoughts, John.


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#39 johninderby-uk

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Posted 03 February 2020 - 04:02 PM

And forgot to mention it comes with a decent carry case.


Edited by johninderby-uk, 04 February 2020 - 08:27 AM.

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#40 25585

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Posted 04 February 2020 - 10:39 AM

In a thread entitled "Sky-Watcher EvoStar 100ED Weight" that I started in December 2018, user db2005 reported that the SW 100ED weighed in at 3.640 kg on a digital kitchen scale.
 
At 4.1 kg, this 80mm f/10 scope and rings that Long Perng is producing must be built like a tank. I have to confess that, after eyeballing the images of this scope, I would not have expected an 80mm scope to weigh in at 9 pounds, though I also confess to not having much meaningful experience with handling refractors.

Long Perng tubes are heavier but good quality. Orion Eons & S-W Equinoxes used Long Perng tubes I believe. TS sell LP scopes. The StellaMiras are in & made by a good company.


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#41 25585

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Posted 04 February 2020 - 10:40 AM

My scope is arriving tomorrow so will post some photos and will check the weight etc.

Will look good on your AZ100!



#42 johninderby-uk

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Posted 04 February 2020 - 11:18 AM

Scope has arrived and will post photos and details shortly but for now here is one photo.

 

      John

 

837-FDFF9-3-DED-4-A44-B9-AA-28-FEBD7-DEA


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#43 25585

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Posted 04 February 2020 - 11:34 AM

My refractoritis is raging strongly alonside mount fever. flame.gif help.gif gve.gif  


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#44 johninderby-uk

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Posted 04 February 2020 - 12:23 PM

Received my StellaMira 80 f/10 ED refractor today.

 

First impressions are what a solid bit of kit and quite hefty at 4.6kg without finder and diagonal. Beautifully finished in glossy black with red accents.

 

Comes with a proper CNC vixen type dovetail bar about 15” long. Found the centre of balance of the scope and set the rear tube ring a couple of inches behind that so that when the handle was fitted it would balance properly. Front ring is close to the dewshield when it is retracted. With such a long dovetail bar easy to balance the scope on the mount.

 

The handle fastens on with a single screw and has notches in the base that fit over the tube ring and stop it from rotating. Nice and smooth with finger grips on the underside and is very comfortable to hold.

 

The focuser has over 90mm of travel and has twist locks with compression rings on both the 2” and 1.25” adapter. The red twist grips are aluminum not plastic.Very easy to use and lock the diagonal  solidly in place. I’m using a Baader T2 prism which should suit this f/10 scope. 2” nosepiece but a 1.25” eyepiece holder for now. Will get a 2” eyepiece to T2 adapter so I can use the 1.25” twist lock adapter as well.

 

Tried a 6x30 RA finder on it but just looked wrong so “borrowed” a 9x50 from another scope. Now I’ll have to buy another 9x50 I suppose. Test fitted a red dot finder to the top of the handle and it fits fine although not planning to use one  but have the option. FLO is looking for another finder shoe as the suppied one doesn’t match the focuser’s finish.

 

Looks nice on the Rowan AZ100 mount but will probably be used more often on the Manfrotto 475 tripod with 405 geared head as it makes a nice grab’n’go setup that can bebcarried outside one handed.

 

OTA without finder or diagonal weighs 4.6kg (10.14lbs) and is 800mm (31.5”) long with the dewshield extended and  670mm (27.5”) with it retracted. That’s without diagonal fitted.

 

      John

2A3F507D-0628-430C-8896-D7FC5D47C8C6.jpeg EE8FFA71-3465-4495-95EF-43A171D0AFFB.jpeg 15383B9B-CB27-4B7C-8F91-7BD205E11867.jpeg 1DEF12EB-CDA9-41E6-B94B-BF70FD3B44A6.jpeg

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Edited by johninderby-uk, 04 February 2020 - 02:55 PM.

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#45 johninderby-uk

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Posted 04 February 2020 - 12:33 PM

More photos.

 

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#46 johninderby-uk

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Posted 04 February 2020 - 12:34 PM

And a couple more.

 

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#47 YAOG

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Posted 04 February 2020 - 01:00 PM

For this scope, From an optical design standpoint, I'm wondering what an LAK Lanthanum would add, if the dispersion of one element is already at FPL53 levels?

 

Why would one want to increase the dispersion of that mating element?

 

You could achieve very effective colour correction with FPL61 or another substitute with less expense at F10.

 

Also it's interesting to see claims of a dual ED triplet lens design on the other models like the Stellamira 104mm F6 (link here https://www.firstlig...-telescope.html )

 

I've never seen a triplet with an extra ED element before, and I wonder what that brings when it's possible to get apochromatic performance with a triplet lens with just one extra high dispersion element.

 

So we'd have two ED elements and one non-ED element.

 

I'd ask for a colour crossing diagram to check if there is benefit in the extra cost. 

There are some double ED scopes out there, Takahashi TOAs employ a double ED design chasing the magic of Fluorite. Here in the USA Orion Telescopes has been marketing a few of these double ED triplets called the X2 line with weak response in the market. It seems few people are willing to pay Takahashi Fluorite doublet prices for an ED triplet scope double ED or not. TS Optics offered these scopes briefly but they are off the site now. 



#48 Gregory Gross

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Posted 04 February 2020 - 02:35 PM

Congratulations on your new acquisition, John! Thanks so much for posting all of those pictures and the very specific information you shared.



#49 johninderby-uk

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Posted 04 February 2020 - 02:42 PM

Thanks.

 

Popped it outside on the photo mount earlier this evening and looked at the moon and absolute razor sharp image with zero CA. And that was with no cooldown time. Tried the Morpheus 4.5mm and image was still bright. No vibrations on the photo mount as well.

 

Unfortunately the clouds rolled in but at least had a bit of a first light and just so impressed. One of those scopes that makes you go WOW when you look through it.

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Edited by johninderby-uk, 04 February 2020 - 02:49 PM.

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#50 Jond105

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Posted 04 February 2020 - 02:51 PM

That is a great looking scope. 




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