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TS-Optics 61EDPH - 5-Element Flatfield Apo 61 mm Aperture F/4.5

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53 replies to this topic

#1 aneeg

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Posted 24 June 2019 - 09:20 AM

https://www.teleskop...ging-apo.kl.jpg

 

This one looks interesting and a perfect match with a CEM 40.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arne

Attached Thumbnails

  • ts-61edph-5-element-flatfield-imaging-apo.kl.jpg


#2 HydrogenAlpha

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Posted 24 June 2019 - 09:50 AM

This is a nice scope indeed, and a nice alternative to the redcat. Don't exactly see how it is a "perfect match" for the CEM40 though. 



#3 aneeg

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Posted 24 June 2019 - 11:04 AM

Portability! A very good travel combination.

 

Arne



#4 junomike

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Posted 24 June 2019 - 01:43 PM

Would make a nice Binoscope!


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#5 aneeg

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Posted 25 June 2019 - 11:02 AM

And with a 2.5» RP focuser this Red Cat is definitely a step up re the other Red Cat.

 

Arne



#6 GlenM

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Posted 26 June 2019 - 09:50 AM

Made by SharpStar. Got one on order without the flattener/reducer. Just different badging.

 

Glen.


Edited by GlenM, 26 June 2019 - 09:54 AM.


#7 25585

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Posted 28 June 2019 - 08:32 AM

And with a 2.5» RP focuser this Red Cat is definitely a step up re the other Red Cat.

 

Arne

Maine Coon version?


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#8 F.Meiresonne

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Posted 26 December 2019 - 07:15 AM

https://www.365astro...-flattener.html

 

Seems the same scope

 

but a huuuuge price difference.

 

Also the TS version seems to miss 2" and 1.25" reducer

 

Sure throws up questions..



#9 F.Meiresonne

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Posted 26 December 2019 - 07:17 AM

Still I am worried about CA. I don't see it in my F/7 (FPL53), this Sharpstar seems also to have a FPL53 doublet but it is at F/5.5...



#10 GlenM

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Posted 26 December 2019 - 08:36 AM

I don't see much CA in mine. You really have to look for it.

 

Glen.



#11 GTom

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Posted 26 December 2019 - 01:29 PM

I am no optics guru, but maybe the additional elements in the reducer keep the CA at bay? It's designed specifically for this scope.



#12 F.Meiresonne

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Posted 26 December 2019 - 01:42 PM

I am no optics guru, but maybe the additional elements in the reducer keep the CA at bay? It's designed specifically for this scope.

I doubt this, as the reducer helps :

 

1 for a flat field in this case

2 reduce the F

 

actually it is a focal reduces and field flattener in one piece.

 

then again i am not a specialist either ...so ...i might be wrong

 

Better is to see what the experiences are from owners.

 

It looks for AP tempting, it is fast , so easier to deal with if you don't guide...because of the fast F

 

but it remains a doublet, FPL 53 yes  but at this focal ratio, some slight color may appear..

 

I just dunno...i just dunno...question.gif scratchhead2.gif thinking1.gif



#13 Benach

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Posted 26 December 2019 - 05:24 PM

Here someone with the optical knowledge. A reducer/flattener can be designed to reduce CA. However, it then only works for a particular set of glass types in the objective. This explains why the Massimo Riccardi reducers/flatteners work primarily on the APM/LZOS objectives and the telescopes with the same objective but different tube such as some models of Officina Stellare. They will not work, at least not by default, on the TEC apochromats.
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#14 Ballyhoo

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Posted 26 December 2019 - 08:08 PM

https://www.365astro...-flattener.html

 

Seems the same scope

 

but a huuuuge price difference.

 

Also the TS version seems to miss 2" and 1.25" reducer

 

Sure throws up questions..

Are we talking about a doublet or quadruplet astrograph?. I for one am quite interested in a widefield astrograph -- not a finderscope looking item likethe Redcat, but that 61mm, or, .

 

This here:

 

https://www.primaluc...quadruplet.html


Edited by Ballyhoo, 26 December 2019 - 08:08 PM.


#15 GTom

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Posted 27 December 2019 - 02:44 AM

Quadruplet means the flattener is integrated, nothing more.


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#16 F.Meiresonne

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Posted 27 December 2019 - 03:38 AM

Are we talking about a doublet or quadruplet astrograph?. I for one am quite interested in a widefield astrograph -- not a finderscope looking item likethe Redcat, but that 61mm, or, .

 

This here:

 

https://www.primaluc...quadruplet.html

Doublet (FPL53) for the lens + 3 lenses for focal reducer/flattener unit

 

So 5 lenses, that makes a pentadruplet or something..how should i call it

 

They have also a 76 mm version , that one has six lenses 3 for the front lenses + again 3 lenses for the reducer/flattener.

 

http://www.sharpstar...n/edph/274.html

 

Gorgious things...


Edited by F.Meiresonne, 27 December 2019 - 03:49 AM.


#17 F.Meiresonne

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Posted 27 December 2019 - 03:41 AM

Here someone with the optical knowledge. A reducer/flattener can be designed to reduce CA. However, it then only works for a particular set of glass types in the objective. This explains why the Massimo Riccardi reducers/flatteners work primarily on the APM/LZOS objectives and the telescopes with the same objective but different tube such as some models of Officina Stellare. They will not work, at least not by default, on the TEC apochromats.

Interesting!

 

The reducer/flattener in this unit is develloped for those scopes, i don't think they are usable in something different

 

Here is a link to their website to download  a jpg  (zipped)

http://www.sharpstar...n/download.html

 

It explains how to screw in filters, but you can see that the reducer/flattener for both kind of telescopes is different

 

(chinese name jpg file, open it, and thank God it is in English)


Edited by F.Meiresonne, 27 December 2019 - 03:46 AM.


#18 F.Meiresonne

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Posted 27 December 2019 - 03:50 AM

Quadruplet means the flattener is integrated, nothing more.

correct!



#19 HydrogenAlpha

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Posted 27 December 2019 - 07:08 AM

Yes it's a doublet, but at these small apertures CA is likely very well managed even at f/4.5. 

 

Calling it a quintuplet, while not technically wrong, is misleading imo. With all the 3 to 4 element reducer/flatteners these days, it doesn't really mean anything when considered in that context. 



#20 HydrogenAlpha

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Posted 27 December 2019 - 07:12 AM

Here someone with the optical knowledge. A reducer/flattener can be designed to reduce CA. However, it then only works for a particular set of glass types in the objective. This explains why the Massimo Riccardi reducers/flatteners work primarily on the APM/LZOS objectives and the telescopes with the same objective but different tube such as some models of Officina Stellare. They will not work, at least not by default, on the TEC apochromats.

Conceptually you're right of course. 

 

However, the Riccardi reducers are marketed as a universal reducer. There is a whole range of LZOS objectives available at a wide range of apertures and focal lengths. The only difference is the optimal backfocus for each model. They are also marketed to work with the TEC apos with appropriate threading adapters, but no modifications to the optical design. 

 

I don't think the Riccardi reducers were designed to reduce CA in any telescope. The LZOS objectives are all triplets and already have fantastic colour correction. 



#21 GTom

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Posted 28 December 2019 - 07:43 AM

That's correct. If it did, it would actually introduce CA in case of many triplets it is usually paired with.
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#22 F.Meiresonne

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Posted 28 December 2019 - 10:46 AM

This scope is a FPL53 doublet.

 

They have a bigger brother, that , is a triplet, comes also with a reducer/FF

 

I ordered anyway.

 

I has to come from the UK, the supplier there offers temporarly 10 % discount, together with shipping cost and an adapter for my eos camera thisis way way lower then any other here in Europe, for the moment

 

Only it will take time to get it, they are out of reducers, shipment should come in within 10 days but guess in practice it might take weeks even months..but i can wait...


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#23 F.Meiresonne

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Posted 28 December 2019 - 10:49 AM

That's correct. If it did, it would actually introduce CA in case of many triplets it is usually paired with.

I thought so too. Any lens impose CA, only thisones are close to the focal plane , and maybe therefore the impact is limited.Or wrong guess?



#24 GlenM

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Posted 29 December 2019 - 06:56 AM

This scope is a FPL53 doublet.

 

They have a bigger brother, that , is a triplet, comes also with a reducer/FF

 

I ordered anyway.

 

I has to come from the UK, the supplier there offers temporarly 10 % discount, together with shipping cost and an adapter for my eos camera thisis way way lower then any other here in Europe, for the moment

 

Only it will take time to get it, they are out of reducers, shipment should come in within 10 days but guess in practice it might take weeks even months..but i can wait...

Did you buy from 365astronomy Freddy?

 

Glen.



#25 F.Meiresonne

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Posted 29 December 2019 - 07:11 AM

Yes Glen

 

Price for the momen for that scope a very low, it is on sale 10% off until 1 st of Januari, so i went for it. But they run out of reducers so i will have to wait until those come in.

 

My wife is a bit mad grin.gif  as i said i did not need anything else anymore but why buy   six months later and pay 100-120 more then,it just does not make any sense..

 

I have a nice little F/6 70 mm scope that is really good visual but for AP the blue halo's around stars is not nice..not nice at all, that disturbs me more then in visual mode.

The sharpstar is a doublet ut it is FPL53,hope that will remedy it sufficient. My TS F/7 102 mm shows no color at all.


Edited by F.Meiresonne, 29 December 2019 - 07:17 AM.



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