BST Shorty Barlow review

[sorrimen]

Hi all

As someone relatively new, I was deciding whether to purchase high power eyepieces or barlow the ones I already owned as budget was a big concern. My eyepieces are BST Starguiders. A BST shorty 2x barlow came up for a good price (£30) and I was very hesitant. Some people said avoid anything but the best barlows, others saying there are very few high power budget eyepieces and to accept the compromise. 

What I found instead is that this barlow works phenomenally with the Starguiders. In my 8” dob (f5.9), the barlowed 25mm compared to the 12mm eyepiece is almost identical (see pictures below). You can just about see the barlow reducing the FOV by maybe 1 degree, but I only noticed this after taking the picture. Visually, I cannot tell the difference. The barlowed 12mm compared to a cheap Meade MA 6mm is night and day, given that I can keep the wide FOV.

If you’re hesitating about this specific barlow, don’t. I can’t vouch whether it’s better than a comparably priced 6mm eyepiece, but you certainly won’t be disappointed by it. 

[Zermelo]

I'll be interested to hear how you find it at night time, when the clouds break. I have a few BST Starguiders, but I've never had a BST Barlow with which to try them.

I wish there were more frequent discussions of Barlows (short and long; with varying number of elements) and telecentrics, and how they perform in particular OTAs with specific eyepieces. I appreciate there are a lot of combinations there but, for example, I have a Celestron Omni Barlow and a Baader Q-turret (the latter magnifies approx 2.25 times, a little more than the former, but both are two-element, short models). I have used both of them with eyepieces from several manufacturers, in three types of scope. The most interesting observation that I have so far relates to how my Baader eyepieces behave with the Baader Barlow, compared with the other. An obvious expectation might be that components from a single manufacturer might work better together*, but I have consistently found the Celestron to be the better choice with my BCO 10mm. Specifically, the amount of scattered light seems to be less with the Celestron. By contrast, my 9mm Morpheus seems happier with the Q-turret.

 

* although I do recall arguing this line a long time ago with a hi-fi buff, in the context of audio components. He disagreed 100%, and always bought what he thought were the best separates, from whichever manufacturer happened to make them

[Ian McCallum]

Does anyone else wonder why there's a G clamp attached to a chimney pot?🤔😂

[sorrimen]

1 hour ago, Zermelo said:

I'll be interested to hear how you find it at night time, when the clouds break. I have a few BST Starguiders, but I've never had a BST Barlow with which to try them.

I wish there were more frequent discussions of Barlows (short and long; with varying number of elements) and telecentrics, and how they perform in particular OTAs with specific eyepieces. I appreciate there are a lot of combinations there but, for example, I have a Celestron Omni Barlow and a Baader Q-turret (the latter magnifies approx 2.25 times, a little more than the former, but both are two-element, short models). I have used both of them with eyepieces from several manufacturers, in three types of scope. The most interesting observation that I have so far relates to how my Baader eyepieces behave with the Baader Barlow, compared with the other. An obvious expectation might be that components from a single manufacturer might work better together*, but I have consistently found the Celestron to be the better choice with my BCO 10mm. Specifically, the amount of scattered light seems to be less with the Celestron. By contrast, my 9mm Morpheus seems happier with the Q-turret.

 

* although I do recall arguing this line a long time ago with a hi-fi buff, in the context of audio components. He disagreed 100%, and always bought what he thought were the best separates, from whichever manufacturer happened to make them

Firstly, that’s a very good point. I should probably have waited until a proper test to review as stars will of course be more sensitive than a chimney. 

I also completely agree that people should post their experiences mixing different things. Can speak from experience with guitar that a Fender amp, Fender lead, and Fender guitar isn’t by default going to work better than a Gibson guitar, Fender lead, and Marshall amp. And with astronomy it’s clear that two things with the exact same description can work entirely different, so I’d bet there are some hidden gem combinations just waiting to be discovered. Thanks for your comment.

[sorrimen]

11 minutes ago, Ian McCallum said:

Does anyone else wonder why there's a G clamp attached to a chimney pot?🤔😂

Oh you bet Ian. Always been my daytime target but never got to the bottom of why someone’s left that there 🤣

[wulfrun]

21 minutes ago, Ian McCallum said:

Does anyone else wonder why there's a G clamp attached to a chimney pot?🤔😂

Does every chimney pot not have one then? Joking aside, it drew my attention more than the image-quality, so you're not alone.

[Zermelo]

More worrying for me, as my brain confined itself to the question of whether the outline of the G-clamp or the imperfections in the chimney pot was the better test of daytime sharpness. The oddness or otherwise of a G-clamp in that setting didn't register at all. 🙈
I wonder how many unexpected objects I've seen and ignored when I've been out observing?

[Louis D]

Never heard it called a G-clamp.  Everyone in the US refers to them as C-clamps.  I guess we just ignore the threaded rod part and focus on the casting part.

Do you Brits call the curved drain pipe under a sink a P-trap or a U-trap or maybe a J-trap or something else entirely?  I'm not talking about an S-trap either.  See below:

[Louis D]

Back on topic, I usually try new eyepieces with at least one of my Barlows to see if it works at all.  Widest true field eyepieces for a given barrel diameter tend to vignette somewhat with non-telecentric Barlows.  Long focal length Barlows tend to outperform short focal length Barlows, given the same number of elements.

An advantage of Barlowing standard long focal length eyepieces over using a standard short focal length eyepiece by itself is the better eye relief in the former relative to the latter.

[ScouseSpaceCadet]

6 minutes ago, Louis D said:

Never heard it called a G-clamp.  Everyone in the US refers to them as C-clamps.  I guess we just ignore the threaded rod part and focus on the casting part.

Do you Brits call the curved drain pipe under a sink a P-trap or a U-trap or maybe a J-trap or something else entirely?  I'm not talking about an S-trap either.  See below:

A "U-bend". 😀

 

Thanks for the review. It's always good to read others' experiences. I picked up a GSO 2.5x ED barlow for a song a couple of years ago and wouldn't be without it. At least compared to the standard achro barlows it's in another league. The BST too seems to be in the ' much better than bog standard' bracket. I wonder how it holds up against the big boys' offerings?

[sorrimen]

Absolutely love how this has turned into a conversation about g-clamps. 

Back to the topic, I imagine side by side with top of the line barlows and teleextenders I’d be able to notice a difference, but that’s some of the beauty of being new; every time I get something even slightly better than the bottom it’s a huge upgrade. For example, I had a 50mm Zennox spotting scope as my ‘telescope’ for about 10 years with a broken zoom eyepiece. The new 8” dob is the equivalent of a Rolls Royce to me and aperture fever is a completely foreign concept right now. Same goes with the BSTs, 60 degrees may as well be 360 compared to my ~40 degree Meade MAs!

[Zermelo]

On 08/06/2022 at 15:47, sorrimen said:

Absolutely love how this has turned into a conversation about g-clamps. 

and don't forget the F-clamp!

 

On 08/06/2022 at 15:47, sorrimen said:

that’s some of the beauty of being new; every time I get something even slightly better than the bottom it’s a huge upgrade

There's a lot in that. I think I'm now passing out of that phase, and diminishing returns are setting in - incremental improvements are smaller, and upgrades are getting more expensive!

 

Edited July 27, 2022 by Zermelo

[sorrimen]

1 minute ago, Zermelo said:

and don't forget the F-clamp!

 

There's a lot in that. I think I'm now passing out of that phase, and diminishing returns are setting in - incremental improvements are smaller, and upgrades are getting more expensive!

 

Never seen anything like that! The difference between G and C is understandable, but if Louis tells me our friends across the pond call this anything other than an F-clamp, there's going to be trouble 🤣

Diminishing returns seems like a big factor in astronomy. Compare the best and the worst and the difference is ludicrous, but each step to get there is small and certainly pricey. Worryingly, despite having already spent far more than I thought I would and having everything I think I need, I'm still checking ABS daily for random deals. Almost bought two pairs of crappy old bins on a whim just because they were cheap. Why would I ever need two binoculars!

[Ian McCallum]

16 hours ago, sorrimen said:

Absolutely love how this has turned into a conversation about g-clamps. 

Back to the topic, I imagine side by side with top of the line barlows and teleextenders I’d be able to notice a difference, but that’s some of the beauty of being new; every time I get something even slightly better than the bottom it’s a huge upgrade. For example, I had a 50mm Zennox spotting scope as my ‘telescope’ for about 10 years with a broken zoom eyepiece. The new 8” dob is the equivalent of a Rolls Royce to me and aperture fever is a completely foreign concept right now. Same goes with the BSTs, 60 degrees may as well be 360 compared to my ~40 degree Meade MAs!

I've been in that place too, as I own an eight inch SW Dobbie with all the BST range of eyepieces (minus the Barlow).

Edited June 9, 2022 by Ian McCallum

[Louis D]

On 08/06/2022 at 12:50, sorrimen said:

if Louis tells me our friends across the pond call this anything other than an F-clamp, there's going to be trouble

Also known as bar clamps. 🤨  I'm not sure what the preferred name is here.

[Zermelo]

"two nations divided by a common tool set"

[sorrimen]

9 hours ago, Louis D said:

Also known as bar clamps. 🤨  I'm not sure what the preferred name is here.

You know what, so long as it’s not another letter I can forgive that

[Mr Spock]

G clamp, seeing as we invented the things 😜

4 hours ago, Zermelo said:

"two nations divided by a common tool set"

Or should that be two nations full of tools?

[bosun21]

On 08/06/2022 at 16:28, ScouseSpaceCadet said:

A "U-bend". 😀

 

Thanks for the review. It's always good to read others' experiences. I picked up a GSO 2.5x ED barlow for a song a couple of years ago and wouldn't be without it. At least compared to the standard achro barlows it's in another league. The BST too seems to be in the ' much better than bog standard' bracket. I wonder how it holds up against the big boys' offerings?

Is that the GSO 2.5x barlow in 1.25”?, or is the ED a 2” model? Thanks 

[ScouseSpaceCadet]

14 hours ago, bosun21 said:

Is that the GSO 2.5x barlow in 1.25”?, or is the ED a 2” model? Thanks 

1.25". At £15 used (like new) that was one of my better astro purchases...

[bosun21]

8 minutes ago, ScouseSpaceCadet said:

1.25". At £15 used (like new) that was one of my better astro purchases...

Yeah, I bought one a good while ago from 365 astronomy for £35. I’ve since learned that it’s far cheaper going the used route.

[Zeta Reticulan]

I'm not sure what Barlow you mean.

Unless you're referring to the 'Omegon' above left. These have multiple elements. I believe they were originally made by Barsta. They're actually pretty good.

[Chandra]

On 6/8/2022 at 5:18 PM, Louis D said:

Never heard it called a G-clamp.  Everyone in the US refers to them as C-clamps.  I guess we just ignore the threaded rod part and focus on the casting part.

Do you Brits call the curved drain pipe under a sink a P-trap or a U-trap or maybe a J-trap or something else entirely?  I'm not talking about an S-trap either.  See below:

In Spain it is called an inverted U siphon, although the U does not seem to me to be inverted... The chimney tool is generally called 'sargento' (sergeant), it comes from the French 'serre-joint' which means precisely 'clamp ', although it sounds similar to the French 'sergeant', and hence the name due to phonetic proximity, nothing to do with military rank. The Barlow operation is somewhat cryptic to me. I always hear that it is better to use a long Barlow tube than a short one, since these vignetting and also require a greater bending of the beams, with the aberration problems that this can entail. However, I also have the Q-Barlow and another 2" Svbony ED shorty (I think it's the same one that OSG builds and sells) and they both seem to do a good job with Baader Ortho and Plössl from the Q-Turret pack, and with the 28mm 2" SW LET and the 42mm 2" OSG SuperView. I don't know how much of a difference in visual quality there can be between short and long Barlows.

[Louis D]

8 hours ago, Chandra said:

The Barlow operation is somewhat cryptic to me. I always hear that it is better to use a long Barlow tube than a short one, since these vignetting and also require a greater bending of the beams, with the aberration problems that this can entail. However, I also have the Q-Barlow and another 2" Svbony ED shorty (I think it's the same one that OSG builds and sells) and they both seem to do a good job with Baader Ortho and Plössl from the Q-Turret pack, and with the 28mm 2" SW LET and the 42mm 2" OSG SuperView. I don't know how much of a difference in visual quality there can be between short and long Barlows.

Shorty Barlows don't have to be bad.  The 1990s Japanese made Celestron Ultima, Orion Shorty Plus, Parks Gold Series 2x Barlow is a very good shorty Barlow.  It uses 3 elements and seems to work about as well as my TV 2x and Meade 140 2x.  On the other hand, I have a generic shorty Barlow from the early/mid 2000s that is so bad (adds fuzziness to image), a guy I permanently loaned it to insisted on giving it back to me after 6 months of use. 🤣

[Chandra]

12 hours ago, Louis D said:

Shorty Barlows don't have to be bad.  The 1990s Japanese made Celestron Ultima, Orion Shorty Plus, Parks Gold Series 2x Barlow is a very good shorty Barlow.  It uses 3 elements and seems to work about as well as my TV 2x and Meade 140 2x.  On the other hand, I have a generic shorty Barlow from the early/mid 2000s that is so bad (adds fuzziness to image), a guy I permanently loaned it to insisted on giving it back to me after 6 months of use. 🤣

It is known that in the practice of amateur astronomy there are many 'myths' that sometimes end up becoming dogmas... The conclusion I always draw is that what matters is the optical and mechanical quality, if something is well built, with good materials, it will work, and usually that comes at a price...