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Which barlow

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#1 2696

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Posted 22 September 2020 - 06:19 PM

Hello everyone, I'm looking for an upgrade for my 1.25" 2x barlow. I was originally going to get the GSO 2.5x APO or the Apertura branded version since the GSO is sold out. But I was also wondering if the TV 2x is worth the extra money.

Any other suggestions are welcome, it would be nice if I can screw the barlow element directly into a 1.25" EP, not entirely necessary though. Thanks.
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#2 russell23

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Posted 22 September 2020 - 07:20 PM

Hello everyone, I'm looking for an upgrade for my 1.25" 2x barlow. I was originally going to get the GSO 2.5x APO or the Apertura branded version since the GSO is sold out. But I was also wondering if the TV 2x is worth the extra money.

Any other suggestions are welcome, it would be nice if I can screw the barlow element directly into a 1.25" EP, not entirely necessary though. Thanks.

What magnification factor are you looking for?

 

I have the GSO 2.5x APO barlow and it is very good.  A couple things to be aware of about it:

 

1.  It's actual magnification factor is actually 2.0 to 2.1x depending upon the eyepiece.

2.  It does require a fair amount of infocus.

3.  It is not threaded for filters.

 

I really like it.  A very good barlow.  I have a hard time comparing it to the 2x TV barlow because I'm not a huge fan of the 2x TV barlow.  The TV barlow might be a little cleaner in the central field, but the GSO seems to feel a little more natural at the edges.   

 

But the 3x TV barlow is great.  If 3x was in consideration I would consider the 3x TV barlow over the 2x.

 

Another 3x barlow that gets really good reviews is the Orion 3x Tri-mag barlow.

 

Dave



#3 2696

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Posted 22 September 2020 - 07:35 PM

What magnification factor are you looking for?

I have the GSO 2.5x APO barlow and it is very good. A couple things to be aware of about it:

1. It's actual magnification factor is actually 2.0 to 2.1x depending upon the eyepiece.
2. It does require a fair amount of infocus.
3. It is not threaded for filters.

I really like it. A very good barlow. I have a hard time comparing it to the 2x TV barlow because I'm not a huge fan of the 2x TV barlow. The TV barlow might be a little cleaner in the central field, but the GSO seems to feel a little more natural at the edges.

But the 3x TV barlow is great. If 3x was in consideration I would consider the 3x TV barlow over the 2x.

Another 3x barlow that gets really good reviews is the Orion 3x Tri-mag barlow.

Dave


I was aware of the GSO magnification, that doesn't really make a difference to me. I'm not entirely sure if I want a 3x, I could be wrong but I just feel it may be too much of a jump in magnification once I throw it on. I had seen the Orion tri-mag earlier, never noticed it before but it doesn't seem too bad. The fact that the GSO isn't threaded for filters is news to me. I'd like to be able to put a Moon filter on there from time to time. Thanks for the input though, definitely will consider the TV 3x over the 2x.

#4 russell23

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Posted 22 September 2020 - 07:42 PM

I was aware of the GSO magnification, that doesn't really make a difference to me. I'm not entirely sure if I want a 3x, I could be wrong but I just feel it may be too much of a jump in magnification once I throw it on. I had seen the Orion tri-mag earlier, never noticed it before but it doesn't seem too bad. The fact that the GSO isn't threaded for filters is news to me. I'd like to be able to put a Moon filter on there from time to time. Thanks for the input though, definitely will consider the TV 3x over the 2x.

If you bought the GSO you could still use filters but you would have to put them on the eyepiece.  Not as convenient, but could be worth it. 



#5 2696

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Posted 22 September 2020 - 07:58 PM

If you bought the GSO you could still use filters but you would have to put them on the eyepiece. Not as convenient, but could be worth it.


You're right, just not convenient. The GSO barrel doesn't unscrew from the top does it?

#6 stubeeef

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Posted 24 September 2020 - 12:23 PM

I love my 2" 2.5x Siebert telecentric with centering adapter. 

 

https://www.sieberto...cs-barlows.html



#7 MartinPond

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Posted 24 September 2020 - 12:52 PM

The TV 2X Barlow is often praised as fully transparent...

I have and love the Orion TriMag,

and the ES 3X telecentric (focal extender), which I use for lower-powered EPs.

 

 

I have found that screwing the optical cell of a Barlow

   into an eyepiece doesn't always play well..some sort of 'near field' effect.

   '

If I screw a Burgess "1.9x OCA"  into a shortie I can get a very clean 1.3--1.5x.

...very useful for cleaning up a field without much gain. 


Edited by MartinPond, 24 September 2020 - 01:55 PM.


#8 2696

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Posted 24 September 2020 - 01:18 PM

I love my 2" 2.5x Siebert telecentric with centering adapter.

https://www.sieberto...cs-barlows.html


Never heard of those but they sure do look nice. I'm definitely going to do some more research on them, I really like the look of them. Thanks for the suggestion.
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