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Celestron Travel Scope 50 or 70 as a Finderscope

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#1 AJ Cadena

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Posted 17 February 2018 - 03:27 PM

Hi,

 

I have an Orion 8" Newtonian in a GEM.

 

I need to replace the finderscope and I read some articles about the Travel Scope 70 for this task.

 

What do you think about the smaller Travel Scope 50 as a finderscope?

 

 

 

 



#2 howardcano

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Posted 17 February 2018 - 05:09 PM

I have the Travelscope 70, and while it would function okay, if you use it with a star diagonal it doesn't operate at full aperture; the focuser drawtube cuts the effective aperture at 0mm of fully-illuminated field to about 62mm.  That's still better than 50mm, but I don't know that the Travelscope 50 uses the full 50mm either.

 

The 70 is light thanks to the plastic focuser, and the focuser does work pretty well at low powers with light eyepieces.

 

The Travelscope 70 uses 1.25" eyepieces, while the Travelscope 50 uses 0.965" eyepieces, so you might want to avoid the 50.


Edited by howardcano, 17 February 2018 - 05:12 PM.

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#3 aeajr

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Posted 17 February 2018 - 05:34 PM

I have the travel scope 50.  My Orion 9X50 RACI is better.


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#4 howardcano

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Posted 17 February 2018 - 05:53 PM

I have the travel scope 50.  My Orion 9X50 RACI is better.

shocked.gif !!!



#5 *skyguy*

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Posted 17 February 2018 - 06:33 PM

The 50mm Travel Scope uses a .965" focuser that has a very long draw tube with a baffle that has a very small opening. It looks like it was designed for a telescope that has a much longer focal ratio than the Travel Scope. The result is a 50mm scope that has been "stopped down" to about 20mm.

 

http://scopeviews.co...avelscope50.htm

 

Although, I do own one  ... it's not a scope I would recommend to anyone that has a any interest in viewing the night sky.

 

The 70mm Travel Scope ... which I also own ... is a completely different story. Considering its price, I've been very impressed with its optical quality and workman-like mechanical build. There's even a male t-thread adapter at the end of the draw-tube that can used to attach a camera that has T-ring adapter.

 

https://www.cloudyni...pe-review-r2486

 

Bottom line ... stay away from the 50mm Travel Scope.


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#6 AJ Cadena

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Posted 18 February 2018 - 12:04 AM

Thanks to all!

 

Very informative information.

 

I´m going to avoid the Travel Scope 50.


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#7 Jon Isaacs

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Posted 18 February 2018 - 12:08 AM

The problem with using these as finders is mounting them so they can be aligned.  That adds considerable expense , complexity and weight.  

 

Jon


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#8 aeajr

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Posted 18 February 2018 - 05:23 AM

This is the 9X50 I have

https://www.telescop...rd=Finder scope

 

 

8X50 RACI - A little lower cost

https://www.highpoin...7QaAgTHEALw_wcB


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#9 AJ Cadena

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Posted 18 February 2018 - 11:57 AM

Thanks Jon and Ed for your helpful information,

 

I think, a direct replacement parts operation, is very practical and money wise, but, some times, an indirect approach, is... well...  you know, itchy... can I do this or adapt that? 

 

I know an indirect path is going to be time consuming and maybe, just maybe I hope, a little bit more expensive and heavy, and in the best case scenario, rewarding, and in the worst case scenario, a solar dedicated little scope and parts for the spare parts box.

 

On the other hand, the RACI finder scopes, are just beautifuly specific purpose built telescopes, waiting in the purchase cart ;)


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#10 Jon Isaacs

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Posted 18 February 2018 - 12:26 PM

Thanks Jon and Ed for your helpful information,

 

I think, a direct replacement parts operation, is very practical and money wise, but, some times, an indirect approach, is... well...  you know, itchy... can I do this or adapt that? 

 

I know an indirect path is going to be time consuming and maybe, just maybe I hope, a little bit more expensive and heavy, and in the best case scenario, rewarding, and in the worst case scenario, a solar dedicated little scope and parts for the spare parts box.

 

On the other hand, the RACI finder scopes, are just beautifuly specific purpose built telescopes, waiting in the purchase cart wink.gif

 

https://www.cloudyni...r-meets-carton/

 

My own mix of the direct and indirect paths.. 

 

One does need to buy a diagonal. 

 

Jon


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#11 zawijava

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Posted 19 February 2018 - 01:51 PM

Thanks to all!

 

Very informative information.

 

I´m going to avoid the Travel Scope 50.

I'm going to try one of the Celestron Micro ED Zoom Spotting Scopes [aka Hummingbirds] as a Finder on my 12.5" Obsession. Either the 7-22x50mm or 9-27x56mm would work. And I like the idea of getting more use out of a Finder than just a Finder.  



#12 Jon Isaacs

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Posted 19 February 2018 - 08:31 PM

 

Thanks to all!

 

Very informative information.

 

I´m going to avoid the Travel Scope 50.

I'm going to try one of the Celestron Micro ED Zoom Spotting Scopes [aka Hummingbirds] as a Finder on my 12.5" Obsession. Either the 7-22x50mm or 9-27x56mm would work. And I like the idea of getting more use out of a Finder than just a Finder.  

 

 

I like getting more out of a finder too . But with the spotters,  you give up the ability to use deep sky filters and wide field evepieces.  And you still have to mount them.  I think a standard astrofinder that takes 1.25 inch eyepieces like the SV-50 is more useful. 

 

Jon



#13 Redbetter

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Posted 20 February 2018 - 01:51 AM

Thanks Jon and Ed for your helpful information,

 

I think, a direct replacement parts operation, is very practical and money wise, but, some times, an indirect approach, is... well...  you know, itchy... can I do this or adapt that? 

 

I know an indirect path is going to be time consuming and maybe, just maybe I hope, a little bit more expensive and heavy, and in the best case scenario, rewarding, and in the worst case scenario, a solar dedicated little scope and parts for the spare parts box.

 

On the other hand, the RACI finder scopes, are just beautifuly specific purpose built telescopes, waiting in the purchase cart wink.gif

 

For an 8" Newt the 70mm Travel Scope is still going to be somewhat large with 400mm focal length, and the true field of view is limited to 3.87 degrees in 1.25" eyepieces--and with the RACI prisms having clear apertures of 21mm or less there will be some vignetting with the 27mm field stops.   As Jon mentioned, you still have to mount it in a way that is adjustable (and likely quickly removable without tools), plus you need an RACI prism for 1.25".  The cost just went way up and the stock focuser is plastic so it can be a bit sloppy.  That said, I am hanging onto mine with the intention of converting it to a finder on some scope, some day when I happen to have collected the parts I want.  I already have an ST80 (same focal length) doing the same duty on the big scope.

 

The main drawback of the stock 50mm finders is that they don't have a standard 1.25" eyepiece holder and RACI prism.  So their flexibility is somewhat reduced in the interest of having small, dedicated cross hair eyepieces.  I have my old Tuthill 8x50mm RA finder which uses an actual 1.25" prism, and therefore can use 1.25" eyepieces in addition to its crosshair eyepiece.  This allows it to accept filters and to work as a poor man's piggy back RFT. 


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