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VITE 2X Barlow Lens Review

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#1 jfriz

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Posted 11 November 2016 - 08:05 AM

This review describes the VITE 2x Barlow lens including my initial impressions of build and optical quality. I observe from a suburb in the southeast U.S. I have one telescope, an 8-inch Dobsonian, and have had it for approximately five years. The photos included in this review represent my first crack at astro-imaging. I wanted to try prime focus photography with my DSLR but my focuser does not have enough in-travel to do so. I used the Barlow to achieve focus with my telescope/focuser/camera combination.

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#2 CQDDEMGY

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Posted 11 November 2016 - 11:52 PM

Thank you for the review.



#3 EJay

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Posted 14 November 2016 - 12:31 AM

Thanks for the review. I bought one of these a while back and have a positive opinion but haven't really compared it to anything else. 



#4 TOMDEY

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Posted 14 November 2016 - 10:26 AM

Interesting; I'm especially glad that you dismembered it so we can see what's inside! I needed a 1.1x Barlow (not available), so bought a bunch of used stock Barlows to examine. Most all are simple, cemented negative achromatic doublets. Yours is of that type. And, like yours, most have that screw-off lens cell. I then worked out the 1st order optical formulae (I'm a retired optics guy) to relate spacing to amplification. I was able to reconfigure a regular Barlow into a "shorty" tube to render it "weaker." But that still did not get me the extremely mild 1.1x that I needed. Finally found the glass I needed in an obscure "new old stock" optics house on the West Coast. An aerospace buddy tipped me off to that source. They even coated it for me!  And a friend down the road built the mount in his machine shop. I paid him with a batch of cookies that my wife made. Thanx for the nice article.  Tom Dey


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#5 Karl Fabian

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Posted 17 November 2016 - 12:31 AM

I bought a Vite so called "5x Apo" barlow more out of curiosity and  took a chance due to the extremely low price of $15 shipped free direct from China. (Ebay purchase and lots of vendors selling this item on Amazon also at the time). Wasn't expecting much and sure enough my expectations were met and then some.  For one thing it is not 5x but 3x. Used with any eyepiece only the very center of the heavily vignetted field is sharp and becomes increasingly blurred and astigmatic away from the center in addition to severe lateral color. The unit is one solid HEAVY metal assembly and the lens assembly appears to be permanently mounted screwed or possibly pressed in to the bottom of the thick heavy barrel. The 15mm lens assembly WILL NOT unscrew even using channel lock pliers! This so called "5x apo barlow is more than likely not even a barlow but probably a re-purposed negative lens assembly meant for another application, and re-machined into a device that looks like a barlow lens with a sloppy fitting  barrel for your eyepiece. The glass looks good with a nice green apparently multicoated surface. The unit may have a qualty lens but whatever it is it is absolutely worthless as a barlow. The 2x looks to be OK  but stay away from the so called "3 element 5X apo" barlow. They are also selling it under other names. WORTHLESS JUNK      https://www.amazon.c...d/dp/B00NG61JIW


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#6 LennyM

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Posted 05 December 2016 - 08:06 AM

In many cases once a short barlow exceeds 2x, (3x to 5x) the optical path becomes exceedingly steep and thus distortion is the result.   For any barlow with a factor greater that 2x, I would recommend going with a longer configuration.   



#7 CzechAstronomer

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Posted 09 December 2016 - 12:15 PM

Interesting; I'm especially glad that you dismembered it so we can see what's inside! I needed a 1.1x Barlow (not available), so bought a bunch of used stock Barlows to examine. Most all are simple, cemented negative achromatic doublets. Yours is of that type. And, like yours, most have that screw-off lens cell. I then worked out the 1st order optical formulae (I'm a retired optics guy) to relate spacing to amplification. I was able to reconfigure a regular Barlow into a "shorty" tube to render it "weaker." But that still did not get me the extremely mild 1.1x that I needed. Finally found the glass I needed in an obscure "new old stock" optics house on the West Coast. An aerospace buddy tipped me off to that source. They even coated it for me!  And a friend down the road built the mount in his machine shop. I paid him with a batch of cookies that my wife made. Thanx for the nice article.  Tom Dey

you seem very experienced! 

 

For what purpose do you need exaclly 1.1x magnification? I cant tell the difference between 125x and 140x. :D well, i can, but it is really minor. 



#8 Waldemar

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Posted 15 December 2016 - 05:47 AM

 

Interesting; I'm especially glad that you dismembered it so we can see what's inside! I needed a 1.1x Barlow (not available), so bought a bunch of used stock Barlows to examine. Most all are simple, cemented negative achromatic doublets. Yours is of that type. And, like yours, most have that screw-off lens cell. I then worked out the 1st order optical formulae (I'm a retired optics guy) to relate spacing to amplification. I was able to reconfigure a regular Barlow into a "shorty" tube to render it "weaker." But that still did not get me the extremely mild 1.1x that I needed. Finally found the glass I needed in an obscure "new old stock" optics house on the West Coast. An aerospace buddy tipped me off to that source. They even coated it for me!  And a friend down the road built the mount in his machine shop. I paid him with a batch of cookies that my wife made. Thanx for the nice article.  Tom Dey

you seem very experienced! 

 

For what purpose do you need exaclly 1.1x magnification? I cant tell the difference between 125x and 140x. :D well, i can, but it is really minor. 

 

I would think adding another piece of glass to get so little gain, only adds more problems, no ?


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