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Nexstar 8" - Questions diagonal and low power EP.

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#26 N3p

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Posted 23 July 2021 - 12:15 PM

Do a good job then pop the question for a well deserved pay rise!?

hahaha it's the Governement, but I do it out of passion really asking nothing in exchange, they know what I need to be happy at the job.

 

Plus, I am going to learn all about the Schmidt-Cassgrain telescope myself, I am quite happy about that.



#27 wrvond

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Posted 23 July 2021 - 12:27 PM

Ok I keep that in mind for the 2" eyepieces, Notdarkenough suggested it also.

 

I didn't had the time to search google yet, In the manual, the telescope comes with 1.25" diagonal, can it take a 2" diagonal directly?

Yes, it can. There are a couple ways you can go:

1. You can get a 2" SCT diagonal. This diagonal attaches directly to the threaded port of the scope. Eliminating the visual back. 

2. You can install a 2" visual back with a separate 2" diagonal.

 

If you directly attach the VB to the scope, you'll get a shorter light path and more clearance between the diagonal and base of the telescope when pointing toward zenith.

If you use a visual back with diagonal, you'll be able to rotate the diagonal so that the eyepiece is pointing in a convenient direction for viewing. In Alt/Az mode, this is not such a big deal. However, there are other advantages insofar as filter use is concerned. With this setup you can install a filter on the diagonal and a filter on the eyepiece. This is really handy when using two single polarizing filters. It allows you to rotate the eyepiece while looking through it to get just the right amount of polarization. Using method 1. you can only thread filters onto the end of the eyepiece.

 

Method 1:

 

Baader 005
Baader 006
 
Method 2 with f/6.3 reducer/corrector:
 
IMG 4218
 
Method 2 without reducer/corrector:
 
back001
 
In method 1. above, I didn't screw the diagonal on because I would have to remove the EP clamp so the body would clear the focus knob, screw it on, then reinstall the clamp. Being lazy, I simply held it up there to illustrate how it would go on. Also, method 1. requires the use of a locking ring. Well "requires" is kind of a strong word, it's only required if you want to orient the eyepiece pointing "up". If you're happy with it pointing where ever it ends up, then the locking ring is optional.
 
Edit: Additionally, you can attach the f/6.9 corrector/reducer directly to the back of the SCT and then attach the SCT diagonal to the reducer. You'll still want to install a locking ring between them, though.
 
Also, keep in mind, the f/6.9 corrector/reducer is not recommended for eyepieces longer than 32mm. 

Edited by wrvond, 23 July 2021 - 12:34 PM.

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#28 N3p

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Posted 23 July 2021 - 02:16 PM

 

Yes, it can. There are a couple ways you can go:

1. You can get a 2" SCT diagonal. This diagonal attaches directly to the threaded port of the scope. Eliminating the visual back. 

2. You can install a 2" visual back with a separate 2" diagonal.

 

If you directly attach the VB to the scope, you'll get a shorter light path and more clearance between the diagonal and base of the telescope when pointing toward zenith.

If you use a visual back with diagonal, you'll be able to rotate the diagonal so that the eyepiece is pointing in a convenient direction for viewing. In Alt/Az mode, this is not such a big deal. However, there are other advantages insofar as filter use is concerned. With this setup you can install a filter on the diagonal and a filter on the eyepiece. This is really handy when using two single polarizing filters. It allows you to rotate the eyepiece while looking through it to get just the right amount of polarization. Using method 1. you can only thread filters onto the end of the eyepiece.

 

Method 1:

 

 
 
 
Method 2 with f/6.3 reducer/corrector:
 
 
 
Method 2 without reducer/corrector:
 
 
 
In method 1. above, I didn't screw the diagonal on because I would have to remove the EP clamp so the body would clear the focus knob, screw it on, then reinstall the clamp. Being lazy, I simply held it up there to illustrate how it would go on. Also, method 1. requires the use of a locking ring. Well "requires" is kind of a strong word, it's only required if you want to orient the eyepiece pointing "up". If you're happy with it pointing where ever it ends up, then the locking ring is optional.
 
Edit: Additionally, you can attach the f/6.9 corrector/reducer directly to the back of the SCT and then attach the SCT diagonal to the reducer. You'll still want to install a locking ring between them, though.
 
Also, keep in mind, the f/6.9 corrector/reducer is not recommended for eyepieces longer than 32mm. 

 

Thanks for the diagonal tutorial, I knew almost nothing on the subject except that the telescope needs a diagonal.

 

Now with these images, I clearly see what's required in order to get quality views with 2" eyepieces, comfort and security of the assembly and eyepiece.

 

I'll remember about the reducer.


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#29 N3p

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Posted 23 July 2021 - 02:19 PM

First thing I’d buy is a TalentCell battery. Unless is is an Evolution.

 

When I first read Nexstar 8, I assumed it was the one made back around 2000 without any other designation.
 

TalentCell they are BO on Amazon.ca, something like this?

 

https://www.amazon.c...27066805&sr=8-4

 

That one is compatible with the Nexstar but do we know the type of female connector adapter to buy in case we get another model of battery.. it looks like a standard connector.



#30 Supernova74

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Posted 23 July 2021 - 02:21 PM

hahaha it's the Governement, but I do it out of passion really asking nothing in exchange, they know what I need to be happy at the job.

 

Plus, I am going to learn all about the Schmidt-Cassgrain telescope myself, I am quite happy about that.

That’s the spirit and a great attitude to have


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#31 N3p

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Posted 23 July 2021 - 02:45 PM

That’s the spirit and a great attitude to have

smile.gif 

 

But hear this, the very first information sent to the private e-mail of the director is a website called "what can you expect to see with a 8" telescope"

 

And that already caused some arguments between him and his wife, she wanted to CANCEL the project after she saw the website shocked.gif  she was probably expecting Hubble like pictures. He decided to buy anyway at least to look at the moon and the planets.

 

Always good to send the "what can I expect to see" website first.. usually before you buy. smirk.gif



#32 Supernova74

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Posted 23 July 2021 - 03:00 PM

smile.gif

 

But hear this, the very first information sent to the private e-mail of the director is a website called "what can you expect to see with a 8" telescope"

 

And that already caused some arguments between him and his wife, she wanted to CANCEL the project after she saw the website shocked.gif  she was probably expecting Hubble like pictures. He decided to buy anyway at least to look at the moon and the planets.

 

Always good to send the "what can I expect to see" website first.. usually before you buy. smirk.gif

Oh dear well that just the tip off the iceberg the money he will most probably spend especially in this hobby 



#33 N3p

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Posted 23 July 2021 - 05:08 PM

Oh dear well that just the tip off the iceberg the money he will most probably spend especially in this hobby 

I don't know where it's going to lead, he has a remote cabin so the telescope will be a huge success there, that's 100% sure for me. It's almost impossible in my opinion to be under a dark sky without a strong need to examine the sky, especially with all the naked eye visible DSOs.

 

I don't know really, he can spend money, but I am very cautious.



#34 N3p

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Posted 05 August 2021 - 01:38 AM

Conclusion of the story,

 

We had our observation tonight and it went very well, everyone was happy with the Nextstar 8SE it's truly a good telescope which gave impressive, sharp views of Jupiter and Saturn. I used the manual 2 star alignment method easily on multiple occasion and taught them how to replicate the procedure with success, how to locate the right stars, how to align the finder with the telescope. So we practised using the finder and alignment they did it successfully by themselves.

 

I suggested to buy the Celestron Zoom 24-8 and it is seriously satisfying with that telescope, the only missing EP with that zoom would be a ES 24mm 68d! (Which was also very good with the telescope, we tried mine.)

 

Finally we successfully used the Goto features without any help from the manual, they did it by themselves to locate the planets, another success.

 

I believe they will have a good time at the dark site next week.

 

100% success! Thanks for the help here with that super nice telescope.


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#35 Notdarkenough

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Posted 05 August 2021 - 08:08 AM

 

Yes, it can. There are a couple ways you can go:

1. You can get a 2" SCT diagonal. This diagonal attaches directly to the threaded port of the scope. Eliminating the visual back. 

 

If you directly attach the VB to the scope, you'll get a shorter light path and more clearance between the diagonal and base of the telescope when pointing toward zenith.

If you use a visual back with diagonal, you'll be able to rotate the diagonal so that the eyepiece is pointing in a convenient direction for viewing. In Alt/Az mode, this is not such a big deal. However, there are other advantages insofar as filter use is concerned. With this setup you can install a filter on the diagonal and a filter on the eyepiece. This is really handy when using two single polarizing filters. It allows you to rotate the eyepiece while looking through it to get just the right amount of polarization. Using method 1. you can only thread filters onto the end of the eyepiece.

 

 

Wrvond and I usually agree on almost everything, but here I disagree. It is never too late for OP's boss, and anyone else reading, to understand the array of adapters provided by Baader for that awesome ClickLock system. Incidentally, my experience is with an 8 EdgeHD on an Evo mount, not an SE, but that isn't an issue here.

For starters, I love my ClickLock! I started with the locking ring but it didn't fit with the Celestron Focus Motor on my rear cell. So I bought an SCT-thread ClickLock Female adapter. Using the supplied 2" nose on the Maxbright diagonal means I can rotate the diagonal completely if desired! No need for the ring, a visual back, etc... I liked the ring idea for mount- clearance concerns at zenith, but the Evo is fine with the SCT-thread female adapter and sliding the OTA forward on the dovetail. I know this isn't possible on an SE, but it is for other readers and another reason the Evo is the better mount. For the OP, look into an Evo when the "upgrade" discussion occurs. Internal battery, integrated WiFi that now works awesome for me, and an adjustable OTA mounting location, kore Aux ports, manual release clutches, etc. I can, and have, threaded filters to the front of the diagonal, rear of the diagonal and eyepiece. To be clear, I never use 3 filters at once! Just mentioning that there are numerous places to thread a 2" filter with the ClickLock system. If you need pics or part numbers just ask and I'll dig around my box of smaller boxes to ensure the proper part number from Baader. 

 

Lastly, keep StarSense in mind! The automatic alignment is wonderful and is the future of astronomy. Sure, manual alignment will be available always (I can still do that with the Evo), but automatic alignment allows non-camera users to use plate solving technology for better alignment as the StarSense camera can see many more stars than the human eye, just like any camera.

 

And lastly, part 2: don't listen to folks who say Tele Vue aren't any good for that scope! They are wonderful! Particularly the 31mm monstrosity for large DSOs! And, look for Rigel Starlight flashlights. They are much better than the others I tried, which were manifold.

 

Best wishes-  Mike


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#36 N3p

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Posted 05 August 2021 - 09:20 AM

I think they are nowhere near any of these upgrades now! But I am glad to get the education myself about the diagonals and the Baader products.




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