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Originally Posted by Profiler
Does anyone know much about the 'Orion Barlow Shorty-Plus 2x (1.25)' its similarity or not with the Celestron Ultima Barlow and how this Orion barlow rates in comparison to the TV 2x barlow or 2.5x Powermate?
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Yes I know quite a lot about it, I owned one for many years
Physically it is very similar to the Celestron Ultima. I am sure it uses the same glass elements, in identical configuration and in the same housing. The coatings are certainly different and if anything I think the coatings are a touch better on the Celestron Ultima. They are both very good barlows and you would likely be happy with either one. However, considering it is only $10 cheaper than the 2X Televue barlow it isn't what I would be buying. Suffice to say I sold my 2X Orion Shorty Plus a few years ago.
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Originally Posted by Profiler
Bintel sell these Orion shorty plus barlows alongside their TV products so I am assuming they can't be too bad, they are clearly labelled as being made in Japan and are priced well above your generic brand barlows and roughly the same price as a TV 2x Barlow.
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A very good barlow but IMO not the equal of the Televue 2X barlow for only $10 difference in price.
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Originally Posted by Profiler
The Orion is described by Bintel as:
"The Orion Shorty-Plus 2x Barlow features an air-spaced, three-element apochromatic optical design of 27mm clear aperture, for superior image sharpness and colour correction. The Shorty-Plus boasts fully multi-coated optics for even greater light transmission. "
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Marketing hyperbole straight off the Orion Website. You need to dig deeper.
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Originally Posted by Profiler
Some months ago when I visited an astro store asking about barlows myself I was advised that good optics in your OTA should be matched with a good barlow.
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Keep in mind that to a large number of people who work in astronomical equipment stores, selling equipment and accessories is "a job". Consequently, they will tell you what they think you want to hear and sell you what they think you might buy.
On the other hand however, some dealers will offer you excellent advice. For example with guys like Don and Michael at Bintel, astronomical equipment is a passion as much as a job; and from people like this you will get good advice.
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Originally Posted by Profiler
In this context I was recommended either a TV 2.5 Powermate or a Celestron Ultima Barlow.
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People have been given far worse advice over the years.
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Originally Posted by Profiler
Given that many OTA’s appear to be frequently made from the one factory and then just re-badged dependent on the company does anyone know whether the Orion Shorty Plus and Celestron Ultima Barlow are simply the same thing with different badges?
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Almost and for all practical purposes it is unlikely you would ever see a difference between the two in the field. If anything the nod would just go the Celestron Ultima, if there was a difference.
Quote:
Originally Posted by Profiler
Finally, does anyone know how does the Orion Shorty Plus compare with either the standard TV 2x Barlow or the TV 2.5x Powermate?
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They are all good barlows and a lot of the differences between them are fairly small and subtle. Of the three my least favourite is without doubt the Orion Shorty Plus.
Optically from a purist lunar/planetary observers point of view the 2X TV Barlow is the best. It is the sharpest and the best optically IMO. The 2.5X TV powermate is marginally inferior to the 2X TV barlow but has a couple of niceties which I like. It preserves the eye relief of the native eyepiece whereas a standard barlow extends it somewhat and with longer focal length eyepieces it can be a little excessive for some people. The other quality about the powermate is difficult to put your finger on. With just about every barlow I have ever used (that's a lot BTW) you usually sense that "something else is in the optical train". The Powermate is different, essentially it just "disappears".
The 2X Shorty Plus IMO comes up a little short of the other two in several performance and mechanical criteria.
1) It is a short barlow and vignettes with some longer focal length eyepieces, more often than not plossls and orthoscopics.
2) It uses a metal set screw to hold the eyepiece as opposed to the compression ring on both of the Televue products
3) Whilst it is well baffled and internal reflections are well suppressed it comes up a little short of the other two products IMO.
4) It is not threaded for filters whereas the TV barlow is
5) It's actual amplification factor is about 2.2X notwithstanding it is advertised as a 2X barlow. It is worth noting you can increase the amplification of standard type barlows by chaning their position relative to the focal plane. You cannot do this with the powermate.
All in all the 2X TV barlow is easily worth the extra $10 IMO. Truth be known I reckon its a $50 or $60 better barlow.
Cheers,
John B