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Ordered from Astrograph. 😁👍🏻👍🏻👍🏻 Rupert says that Tecnosky are increasing their prices on March 1st so looks like that’s another brand that’s about to be hit by price rises.  Hated selling th

Already taken care of:

Yes 🙂🙂🙂🥳🥳🥳 The scope is being shipped from Astrograph today so not much longer to wait. Ordered on Sat 13th so not bad considering it had to be shipped from Italy to Astrograph.. 👍🏻

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9 hours ago, JamesF said:

Why do you need a towel rail on your new telescope?

James

Interesting.  They're usually called towel bars in the US.  We do have handrails for steadying ourselves, though.

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On 12/02/2021 at 18:17, johninderby said:

From what I have read the doublet has advantages such as quicker cool down than the triplet and visually very close in performance but would expect the triplet to have the edge for AP. The triplet would require a stronger  mount.

Think it comes down to how much AP ypu would use it for.

My 90mm FPL-53 triplet takes about 30 minutes to warm up 10 to 20 degrees F when I take it out of my air conditioned house during our hot, Texas summers.  Until then, the star images at high power are all spiky.

I had looked at that 125mm, but decided it would be too heavy for my DSV-2B mount.  It's only rated up to about a 102mm f/7 refractor.  I saw the used 90mm triplet for a good price and jumped on it.

Edited by Louis D
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Not trying to hijack this thread , but how much the performance increases from a 100mm apo to a 125mm apo ? Does that make either of these scopes redundant ? 

Edited by Voyager 3
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I feel there's a really noticeable jump from 4" to 5", but not such a noticeable jump from 5" to 6".  Light grasp will be the most obvious improvement, and if the lens figure is really good, the scope should have an advantage in planetary performance too.

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5 hours ago, Louis D said:

My 90mm FPL-53 triplet takes about 30 minutes to warm up 10 to 20 degrees F when I take it out of my air conditioned house during our hot, Texas summers.  Until then, the star images at high power are all spiky.

I had looked at that 125mm, but decided it would be too heavy for my DSV-2B mount.  It's only rated up to about a 102mm f/7 refractor.  I saw the used 90mm triplet for a good price and jumped on it.

Funny how you chaps have the opposite problem to us. It’s always warm house to cold outside here!

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4 hours ago, Voyager 3 said:

Not trying to hijack this thread , but how much the performance increases from a 100mm apo to a 125mm apo ? Does that make either of these scopes redundant ? 

Here’s the difference between a 102 f/7 and a 125 f/7.8 with a 25mm eyepiece.

102 f/7

F9073408-CF05-4D62-98A3-24E545068A06.jpeg7

125 f/7.8

E4394507-2B9C-472E-9907-1CE7EAF47F7F.jpeg

Edited by johninderby
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4 hours ago, Voyager 3 said:

Not trying to hijack this thread , but how much the performance increases from a 100mm apo to a 125mm apo ? Does that make either of these scopes redundant ? 

I don’t think I would ever be without a 4” scope, if only for the sheer convenience and portability whilst still offering great performance. A 5” is still well worth having, but there will be times when you can’t take it with you, or just want something more convenient.

Do I want a decent 5” apo at some point? You betcha! As has been said, 25% extra resolution but in a package more portable package that will cool quicker and be much more useable than a 6”.

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By contrast, I have a 4" Flourite and a 5" triplet that I've used probably no more than twice in the last 5 years.  I also have a 150ED that gets used frequently as it's mounted on a larger telescope as a finder/general purpose telescope.  I don't need to G & G and I rarely take a telescope anywhere else, usually once a year to Kelling.      🙂 

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1 hour ago, Stu said:

I don’t think I would ever be without a 4” scope, if only for the sheer convenience and portability whilst still offering great performance....

 

Yep, me too. 100mm F/9 vs 130mm F/9. 4Kg vs 9.5kg:

tmbtak01.JPG.5f2cacf974ca924a4488163ef48f0dbc.JPG

To be fair, a 150mm F/8 doublet is about the same size and weight as the 130mm triplet though.

 

Edited by John
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1 hour ago, Peter Drew said:

By contrast, I have a 4" Flourite and a 5" triplet that I've used probably no more than twice in the last 5 years.  I also have a 150ED that gets used frequently as it's mounted on a larger telescope as a finder/general purpose telescope.  I don't need to G & G and I rarely take a telescope anywhere else, usually once a year to Kelling.      🙂 

To be fair Peter, I think most of us would opt for a 6” observatory mounted apo if we had a choice! 🙂

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3 hours ago, John said:

Yep, me too. 100mm F/9 vs 130mm F/9. 4Kg vs 9.5kg:

tmbtak01.JPG.5f2cacf974ca924a4488163ef48f0dbc.JPG

To be fair, a 150mm F/8 doublet is about the same size and weight as the 130mm triplet though.

 

John are your Tak 100 and SW 120 more alike than different ? ( In light gathering and resolving power ) 

Edited by Voyager 3
Stupid autocorrector !
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22 minutes ago, alex_stars said:

Hi @johninderby and all,

I have also one of those on order, should be delivered next week. Looking forward to try it out! Did you get yours already?

Just ordered on Sat so looks like 7 to 10 days. 

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1 hour ago, Voyager 3 said:

John are your Tak 100 and SW 120 more alike than different ? ( In light gathering and resolving power ) 

The other scope in that picture is my 130mm F/9 TMB/LZOS triplet. 

The SW ED120 is in this picture along with my Vixen ED102SS, the Tak and the TMB/LZOS:

4refractors.JPG.0ad5fd924379390b2bacfe7fb33e6a61.JPG

The Tak gets very close to the SW 120 in terms of resolution but the additional 20mm is noticed on really tight binary stars and in light grasp on deep sky objects.

The TMB/LZOS performs very like the Tak in terms of pure image quality but with 30% more aperture. I guess similar to a Tak TOA 130 ?

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  • johninderby changed the title to Tecnosky FPL-53 ED Doublet

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