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New SharpStar 15028HNT - Initial impression with pics!

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#126 Ladyhawke

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Posted 12 September 2019 - 12:34 PM

I read the whole thread (almost all) and I am still not sure. Is this a yay or nay? I won’t be using with a full frame, just an Atik 460 and an ASI 1600, it seems like most comments are about this scope with a full frame camera. I am itching to place an order but I am not sure... I want perfect stars all over, am I expecting too much?


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#127 andysea

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Posted 12 September 2019 - 01:29 PM

Very good question! I am not sure yet. I need a good imaging session with the scope and then I will be able to offer my feedback. So far all I did is learn how to collimate it. I had two imaging sessions prior to that but the scope was too far out of collimation and the data was a throwaway.

Edited by andysea, 12 September 2019 - 01:30 PM.

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#128 rockstarbill

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Posted 12 September 2019 - 08:45 PM

Well, to validate the collimation of the scope -- no stars are needed, not for mechanical purposes anyhow. 

 

Can you take a photo of the Telecat with a white sheet of paper blocking the primary, then take another image through the Telecat of the scope with a white sheet of paper blocking the front of the scope? 

 

A better way to set this up would be to install a HotSpot on the primary mirror, and do a full Catseye collimation. 



#129 psandelle

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Posted 12 September 2019 - 09:10 PM

I read the whole thread (almost all) and I am still not sure. Is this a yay or nay? I won’t be using with a full frame, just an Atik 460 and an ASI 1600, it seems like most comments are about this scope with a full frame camera. I am itching to place an order but I am not sure... I want perfect stars all over, am I expecting too much?

Yeah, I’m waiting, too, and I do want it full frame, or I’d just get another PowerNewt. Sigh. This is a frustrating one as the QC seems less than stellar, and that’s always a worry.

 

Fingers crossed.

 

Paul


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#130 rockstarbill

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Posted 12 September 2019 - 09:12 PM

Yeah, I’m waiting, too, and I do want it full frame, or I’d just get another PowerNewt. Sigh. This is a frustrating one as the QC seems less than stellar, and that’s always a worry.

 

Fingers crossed.

 

Paul

I sent a note to TS Optics, whom also sells this, rebranded. I asked if they check all of these downfalls, collimate the scope, and also asked if they will install a Catseye spot on it. 

 

https://www.teleskop...arbon-Tube.html


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#131 andysea

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Posted 12 September 2019 - 09:16 PM

I think there are a few improvements necessary to the collimation screws for the primary. I will do another tear down this weekend and see if I can replace the stock screws with nylon tipped hex set screws.
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#132 psandelle

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Posted 12 September 2019 - 09:19 PM

I sent a note to TS Optics, whom also sells this, rebranded. I asked if they check all of these downfalls, collimate the scope, and also asked if they will install a Catseye spot on it. 

 

https://www.teleskop...arbon-Tube.html

I was going to buy from them, originally. If they do that, I might consider taking the plunge. They’ve always done right by me.

 

Paul


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#133 rockstarbill

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Posted 12 September 2019 - 09:21 PM

I was going to buy from them, originally. If they do that, I might consider taking the plunge. They’ve always done right by me.

 

Paul

Agreed. It is also currently on sale too. :) 


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#134 RogeZ

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Posted 12 September 2019 - 09:23 PM

Have you consider an Epsilon 130? You are not too far on price and its built like a tank.
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#135 rockstarbill

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Posted 12 September 2019 - 09:24 PM

Have you consider an Epsilon 130? You are not too far on price and its built like a tank.

Considering the central obstruction -- its not all that compelling. The E160 on the other hand... that is no longer made... 


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#136 psandelle

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Posted 12 September 2019 - 09:25 PM

Considering the central obstruction -- its not all that compelling. The E160 on the other hand... that is no longer made... 

If only...if only....

 

Paul



#137 andysea

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Posted 12 September 2019 - 09:26 PM

I did consider the e130 but it’s about 20% slower. I would rather just get the 180.
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#138 syxbach

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Posted 12 September 2019 - 11:57 PM

Hi Andy

 

Sorry for the frustration on the collimation. Imagers start to use this scope in China. Some of them got pretty good results, One of them used 16200; one used 8300.

 

https://www.astrobin.com/users/gxlysg/

 

This following link is from a Chinese forum (in Chinese), but you can see the collimation is really good.

 

http://bbs.imufu.cn/...787005-1-1.html

 

I also plan to image with this scope. Definitely will try in the future.

 

Yuexiao

 

I did consider the e130 but it’s about 20% slower. I would rather just get the 180.



#139 andysea

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Posted 13 September 2019 - 12:49 AM

No frustration here. I think that collimation is going to be critical with any f2.8 Newtonian system.
I saw the images taken with the 16200 camera and they are pretty much in line with what I am seeing in my test shots. in the astrobin posts, the stars at the corners are far from perfect. This might be normal.

#140 RogeZ

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Posted 13 September 2019 - 07:49 AM

I dont see what is the effect of the central obstruction on a F3.3 astrograph. The challenge with these cheaper scopes is the mechanics. Subpar mechanics means almost impossible to hold collimation. Talk to a PowerNewton owner...

#141 cabfl

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Posted 13 September 2019 - 08:14 AM

PowerNewton UNC or ONTC?

 

UNC and BorenSimons have flexion problems.

ONTC are stiff as rocks, if you put a good focuser on it.


Edited by cabfl, 13 September 2019 - 08:15 AM.

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#142 psandelle

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Posted 13 September 2019 - 08:54 AM

Hey, there! I loved my PowerNewts! They held collimation for me (one was from the original guys, Boren and Simon, one from TS). But I agree, if the Sharpstar can't hold colly, then it's dead to me. Dead I say!

 

Paul



#143 andysea

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Posted 13 September 2019 - 11:22 AM

Here is another improvement that I recommend upon receiving the scope.

See the  attached photo. The set screws of the primary mirror cell appear to be cut to a certain length and they have sharp edges at the end. They are eating into the rear tabs of the aluminum primary mirror cell. 
I'm going to replace them with nylon tipped set screws. I'm learning that from my DSI/RCOS that has all set screws nylon tipped. The nylon tip provides a very positive solid feedback as opposed to the "mushy" feel of these cut off screws. They will also stop tearing into the aluminum cell.

 

I have asked the manufacturer if I can purchase a new part to replace the damaged one.

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#144 psandelle

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Posted 13 September 2019 - 12:28 PM

Here is another improvement that I recommend upon receiving the scope.

See the  attached photo. The set screws of the primary mirror cell appear to be cut to a certain length and they have sharp edges at the end. They are eating into the rear tabs of the aluminum primary mirror cell. 
I'm going to replace them with nylon tipped set screws. I'm learning that from my DSI/RCOS that has all set screws nylon tipped. The nylon tip provides a very positive solid feedback as opposed to the "mushy" feel of these cut off screws. They will also stop tearing into the aluminum cell.

 

I have asked the manufacturer if I can purchase a new part to replace the damaged one.

I'm a "hit 'buy now' on Amazon" kinda guy, so if you find a particular screw of a particular length that works, could you report what it is? I'm keeping track for the time, if I decide to buy, learning from those brave pioneers such as yourself who go forth into the Magellanic unknown to fight the terrors of bad QC and wonky collimation and unpainted nuts and bolts so that the rest of us can have a smoother voyage.

 

Paul


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#145 rockstarbill

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Posted 13 September 2019 - 12:30 PM

On the topic of TS Optics, they bench test and setup the scopes for you. They cannot change the center spot though.



#146 andysea

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Posted 13 September 2019 - 12:42 PM

I'm a "hit 'buy now' on Amazon" kinda guy, so if you find a particular screw of a particular length that works, could you report what it is? I'm keeping track for the time, if I decide to buy, learning from those brave pioneers such as yourself who go forth into the Magellanic unknown to fight the terrors of bad QC and wonky collimation and unpainted nuts and bolts so that the rest of us can have a smoother voyage.

 

Paul

Amazon has them but they have a one month lead time. I placed the order anyway because they are cheap.

Here is the link

https://www.amazon.c...0?ie=UTF8&psc=1

 

I will keep looking. McMaster Carr has 10mm long ones. They might work.

 

In the meantime I will probably just use standard round tip grub screws. The logic behind using sharp edged set screws goes beyond me.


Edited by andysea, 13 September 2019 - 12:43 PM.

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#147 andysea

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Posted 13 September 2019 - 12:46 PM

well that is strange....I bought the screws at $3.36 ea. and now amazon shows a price of $10.32 ea.



#148 psandelle

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Posted 13 September 2019 - 12:49 PM

Oh, man, your one order drove the price up 3Xs!!!

 

Paul


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#149 psandelle

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Posted 13 September 2019 - 12:50 PM

On the topic of TS Optics, they bench test and setup the scopes for you. They cannot change the center spot though.

That sucketh. Maybe some place more local might do it. I'll ask around. I just can never center those dang center spots myself.

 

Also, I gather one can't really change out the focuser as the reducer/corrector is somehow "special?" Is that the case, or was that something I imagined, or heard from TS before they came out?

 

Paul



#150 andysea

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Posted 13 September 2019 - 07:17 PM

Ok I found anther source from Ebay 

 

https://www.ebay.com...872.m2749.l2649

 

I cancelled the Amazon order because the screws were too short, I ordered the 18mm long ones. Both the 18mm or the 22mm long will work.


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