12 replies to this topic

[Procyon]

1.5x Antares Twist-lock Shorty Barlow

 

https://www.scopestuff.com/ss_ebt2.htm

 

Bottom Lens (Aprrox 1.5x) of a 2x Shorty Barlow

 

https://www.ebay.com/itm/314804314345

 

Masuyama 1.25″ Barlow - 1.5x

 

https://stellaroptix...low-lenses-1-5x

 

Meade Series 4000 #140 2x Apochromatic Barlow Lens (Aprrox 1.2x)

 

https://www.opticspl...arlow-lens.html

 

Baader Dual Factor Q-Barlow 2.25x/1.3x

 

https://telescopesca...b33a21cbc&_ss=r

Edited by Procyon, 16 March 2025 - 09:58 AM.

[GalaxyPiper]

I don't see why not. 

 

Binoviewers are basicly transmission optics. They only transmit the current view. They, in of themselves, do not magnify or reduce an image, only transmitting the same view twice.

Edited by GalaxyPiper, 16 March 2025 - 09:52 AM.

[Procyon]

I don't see why not. 

 

Binoviewers are basicly transmission optics. They only transmit the current view. They, in of themselves, do not magnify or reduce an image, only transmitting the same view twice.

Think they'll all perform about the same quality wise?

[GalaxyPiper]

Think they'll all perform about the same quality wise?

No...but that's a guess on my part.

 

But then, you switched questions. Your first question was about Binoviewers working with any of these barlows.

Then asked a quality question about these barlows themselves.

Edited by GalaxyPiper, 16 March 2025 - 10:11 AM.

[betacygni]

They will all work, but the magnification values will be significantly higher due to the increased light path of the binoviewer. The amount of which will depend on the focal length of the barlow (which is sadly almost never advertised). For example a 2x Barlow will typically work around 3x with a binoviewer.

Also, the amount of light path compensation will vary, and you might not be able to achieve focus with all barlows.

[Procyon]

No...but that's a guess on my part.

 

But then, you switched questions. Your first question was about Binoviewers working with any of these barlows.

Then asked a quality question about these barlows themselves.

True, because you answered the first question. 

[GalaxyPiper]

https://telescopethe...om/barlow-lens/

[betacygni]

Which binoviewers do you have, and what amplification value ideally are you looking to achieve? Those would probably guide the selection process best. That said, you generally get what you pay for in optics. I’d avoid the very cheapest options unless you’re on a strict budget.

[Procyon]

Which binoviewers do you have, and what amplification value ideally are you looking to achieve? Those would probably guide the selection process best. That said, you generally get what you pay for in optics. I’d avoid the very cheapest options unless you’re on a strict budget.

Just a simple new Arcturus bino. 

 

Want to try the Zeiss 25mm pair I have with multiple magnifications to see if I need a 2nd pair.

[quercuslobata]

I use an astro-tech 2X telecentric barlow ($59) in my Baader binoviewers and I couldn't be happier with it (and I have a 2.5 power mate for comparison). The telecentric will keep it closer to the advertised magnification. And if you ever upgrade to the Baader binoviwer it has a t2 thread and can be used as the nosepiece which reduces the total height of barlow and binoviewer.

Edited by quercuslobata, 16 March 2025 - 06:42 PM.

[RobBob]

With my Orion linear BV, only focal extender works.  I have the ES focal extender 2x and it is very good.  The best is supposed to be the Televue.

[Shorty Barlow]

 

 

AFAIK Celestron have no GPC's available for their BV. I threaded the element off of a 2x short SvBony Barlow. The Barlow had a standard 22mm barrel. I estimate this to magnify the BV eyepieces by about 1.6x. This seems to be borne out with trials I have undertaken with a variety of comparison tests in daylight. It's worth pointing out that focal planes of Barlow elements vary. Standard GSO short Barlow 30mm barrel element focal planes will be different to more standard 22mm barrels. My guess is that the GSO element would give a slightly higher magnification (1.8x?).

 

 

I originally acquired a 1.6x 'Omegon' element for the BV, but the threads kept sticking & I didn't want to force the element onto the nosepiece. After trying several elements, the SvBony turned out to have exceptionally smooth threads, with a pretty high quality housing & glass element.  

Edited by Shorty Barlow, 19 March 2025 - 04:51 PM.

[photoracer18]

When I was beta testing for Denkmeier way back when the only OCS unit available was the SCT Star Sweeper. One of the scopes I tried to use the BV on was the Vixen ED114SS (no OCS for it), but the F-ratio at F5.3 was too short and not enough back focus. All I had was our Proxima 2" 1.5x Barlow (later sold as the Antares 2" 1.6x Barlow). It turned out to work wonderfully.  I was using it in front of the diagonal so its actual magnification was something like 2.25x approximately. I never tried any 1.25" Barlows even though I had a Celestron Ultima Barlow later on.

Edited by photoracer18, 25 March 2025 - 01:42 PM.