quality 1.25" barlow

[GrahamL]

I'm looking for one to give me some planetary options with decent eyerelief for my 8.5 and 14 pentaxes.

televues seem pretty nicely priced at bintel atm
Is there any others that measure up ?

cheers graham

[bobson]

I have 3 Barlows: 3x TeleVue, 2x Skywatcher and 2x 2" some Japanese made Barlow.

From all of them I mostly use 2x 2" Barlow and would recommend that one over other ones because you can use it for both 1.25 and 2". Of course providing you have 2" focuser.

TeleVue 3x Barlow I use only on rare occasions and its excellent Barlow but would be better if i bought 2x instead 3x. I use it with my Pentax XW 10 mm on Moon and planets.

Skywatcher 2x Barlow is not that bad at all but I use it mostly for my Barlowed laser collimation.

bob

[ausastronomer]

Hi,

I have several barlows including a 1.25" 2.5X TV Powermate, a 1.25" 1.8X Televue barlow and a 2" 1.6X Japanese made Antares barlow.

They are all very good and you would be happy with any of them. The 1.8X TV barlow is an early version of the 1.25" 2X TV barlow. IMO the best value for money barlow at present is the 1.25" 2X TV barlow. It is an exceptional performer and isn't overpriced.

The 2" 2X Japanese made barlow that Bob mentions is also very good. It is sold under several disguises including University Optics and Orion USA.

Having said that and notwithstanding I own a 2" barlow, I just never ever use it. I only use my barlows to achieve higher powers than I can achieve with my 1.25" native eyepieces and I always do that with my 1.25" 2.5X TV Powermate or my 1.25" 1.8X TV barlow. Invariably the only eyepieces I ever barlow are the 10mm, 7mm and 5mm Pentax XW's and the 8.5mm Pentax XF. It just depends on where the seeing runs out.

Cheers,
John B

[Liz]

I dont use barlows, but want to give them a go.
I did have one little crappy on (?brand/type) but this week (probably due to this thread ;)) purchased a TeleVue barlow x2 (not the Powermate which quite a bit more expensive :sadeyes:) - it has some great reviews, and price was Ok. Cant wait to get it!!
Thanks for that extra info John.

[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?

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.

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. "

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.

In this context I was recommended either a TV 2.5 Powermate or a Celestron Ultima Barlow. I have never heard of the latter but earlier this week when I looked at the Astronomics website found it. See below:

http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_name/U6SQ7CTJP98X9JKRW39JAMFHD0/product_id/720 (http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_name/U6SQ7CTJP98X9JKRW39JAMFHD0/product_id/720)

What struck me was that aside from the orange paint labelling on the Celestron (as opposed to white paint labelling on the Orion) the physical shape and appearance of the Celestron and the Orion Shorty Plus essentially look identical to me.

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?

Another possible clue to this conundrum is that when conversion of the US to Aus dollar is taken into consideration the Celestron Ultima Barlow and Orion Shorty Plus are also roughly the same price.

Finally, does anyone know how does the Orion Shorty Plus compare with either the standard TV 2x Barlow or the TV 2.5x Powermate?

[DavidU]

I have used the Celestron Ultima 1.25" barlow for years and am very happy with it.

[Profiler]

Yep - thats the one - however - do you know whether the Orion Shorty Plus 2x is the same thing as physically they look identical to me save for orange paint on the Celestron and white paint on the Orion?

[ausastronomer]

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.



A very good barlow but IMO not the equal of the Televue 2X barlow for only $10 difference in price.



Marketing hyperbole straight off the Orion Website. You need to dig deeper.



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.



People have been given far worse advice over the years.



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.



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

[The Mekon]

I ahve to agree with the previous posts.
Celestron Ultima has been in my kit for 12 years, and well matches the performance of the AP130 EDT.

[GrahamL]

Thanks for all the comments, as i've only got 3 eyepieces I can't see much use for a 2" barlow. I've almost bought a couple of high priced
eyepieces down around the 5 mm spot but always change my mind
realisticly I'm not going to get a lot of use upwards of 200x whatever I choose so a barlow is probably as good a choice.

So the14 xw and 8.5 pentax barlow well John?

thanks again

[ausastronomer]

Hi Graham,

Sorry I didn't come back to you earlier. I missed your post.

Both eyepieces barlow very well in any good quality barlow.

The only rider I could add is that the 14mm XW with it's native 20mm of eye relief, IMO is just a tad "nicer" comfort wise to use in the powermate because it preserves the eye relief at 20mm.

Cheers,
John B

[GrahamL]

Thanks John , I'll get one soon , I've been getting into a lunar observing of late and have just bought a 6mm ortho so the barlow will have to wait for some more good behaviour to build before buying .:)