17 replies to this topic

[acem77]

Still on the hunt for this so I can use a bino viewer with my DOB.

If not available on the second hand market does anyone know if there's another brand that's the equivalent to this. I'm not really sure how to cross reference the specs easily.

I will also keep on the hunt for the original GPC. Feel free to message me if you have one available for sale.


Thanks

[Bintang13]

I use the Siebert Optics 1.3x OCA for Dobs it fits into the focuser and attaches to the binoviewers with the option of a T2 thread or 1.25” opening. Also use the Williams Optics 2x Barlow for binoviewers as well. Still use both with conventional binoviewers and Dobs. Mostly now mostly use the linear binoviewers for deep sky with the Dobs.

 

Jim

[junomike]

Did you call KWtelescopes (Canada)?

 

They show them as on hand (apparently).

[acem77]

Thanks, unfortunately like many others the sites lists it but they do not have it. In an email they said it was discontinued.
Small hope for new old stock in the wild..

Did you call KWtelescopes (Canada)?

They show them as on hand (apparently).

[acem77]

I use the Siebert Optics 1.3x OCA for Dobs it fits into the focuser and attaches to the binoviewers with the option of a T2 thread or 1.25” opening. Also use the Williams Optics 2x Barlow for binoviewers as well. Still use both with conventional binoviewers and Dobs. Mostly now mostly use the linear binoviewers for deep sky with the Dobs.

 

Jim

Thanks I am now highly considering a linear binoviewer. I see one from Orion are there other brands to consider?

[Bintang13]

Hi acem77,

 

If you are primarily viewing the moon and planets I would recommend staying with a conventional binoviewer. You will be able to achieve focus with just a Williams Optics 2x  Barlow for binoviewers just add spacers to get there if it doesn’t already. It should put you between 2 and 3 times amplification which you can calculate more precisely after achieved.The WO 2x Barlow outperformed alternatives costing several times more, in my opinion. For lower powers the Siebert 1.3x OCA replaced the Baader 1.7x which I had and sold. I do now prefer the Orion Linear Binoviewers for low powers in a Dob. They are the same sold under different brands mentioned above. With the linears stay as close to the field stop limit when choosing eyepieces. Hope this helps some. Also I don’t know if you have placed a want ad for the Baader unit in the classifieds that had worked for me in the past.

 

Jim

[acem77]

I plan to view everything

I really do not want to double down on two types of binoviewers.

From what I read the linear style creates some light noise/artifacts when viewing planets and the Moon. I'm not sure what to expect and if that's really a deal breaker to me considering the amount of investment to have both styles and all the other issues with a traditional viewer with my setup.

[Bintang13]

Conventional binoviewers are more versatile as mentioned by others the linears seem to be preferred in reflectors for low power. 

[Bintang13]

For conventional binoviewers in a Dob I use an In-Travel adapter to achieve focus with the WO 2x Barlow. It also helps by putting the binoviewer’s center of gravity closer to the focuser. Actually I use an In-Travel adapter for the linears for that reason as well.

Edited by Bintang13, 20 April 2024 - 12:08 PM.

[acem77]

For conventional binoviewers in a Dob I use an In-Travel adapter to achieve focus with the WO 2x Barlow. It also helps by putting the binoviewer’s center of gravity closer to the focuser. Actually I use an In-Travel adapter for the linears for that reason as well.

 

I would consider buying this

https://www.highpoin...osepiece-bino-2

 

A 2nd 

https://www.highpoin...epiece-hyp-zoom

 

Plus 

In-Travel adapter, if 2inch not sure if I need the nose piece.

 

I would hope to skip the Barlow but if using a traditional binoviewer I don't think it can be avoided?

Edited by acem77, 20 April 2024 - 01:06 PM.

[Bintang13]

Those are great choices. I don’t use the Baader zoom in the binoviewers because even with the cups removed they don’t fit comfortably. We have had the Baader Maxbright 2 for a few years and can highly recommend them. You will still need an amplifier of some kind to reach focus unless you have a Truss Dob that can be lowered.

Edited by Bintang13, 20 April 2024 - 03:19 PM.

[betacygni]

I plan to view everything
I really do not want to double down on two types of binoviewers.
From what I read the linear style creates some light noise/artifacts when viewing planets and the Moon. I'm not sure what to expect and if that's really a deal breaker to me considering the amount of investment to have both styles and all the other issues with a traditional viewer with my setup.

Trouble with the Linear is you’re limited to about 17.4mm field stop eyepieces. A conventional binoviewer with a 2x amplifier to reach focus will have a slightly smaller field of view, but the larger prism you’re starting with makes this a smaller difference that it might seem, and you should enjoy high power benefits with a conventional binoviewer. If your scope has the back focus for a 1.6x amplifier it’s nearly identical true field as the linears. I recommend looking at what exit pupils you really use. You can get a 3mm exit pupil with conventional binoviewers and a 2x amplifier, I find this plenty large in my reflectors (in fact I tend to stay closer to 2mm for deep sky).

Edited by betacygni, 20 April 2024 - 11:19 PM.

[acem77]

Repeating this from another post but I figure that update it here also..

Received my linear binoviewer
Omegon Binocular Head Pro Tritron bino-viewer.
And 2nd Baader Hyperion Mark IV.

I am really happy with this setup.
Works good at both extremes of the Mark IV lenses capability. I have to unscrew the eye spacers and use the rubber eye cups to allow the IPD distance for my nose to achieve alignment and add magnetic counter weights to the dob.

Took a little extra time to get used to it but
I am going to find it hard to go back with a single lens.

So far I've only been able to view the stars, moon and the sun. It was a real treat seeing the big sunspot that caused the aurora this last weekend.

Can't wait to try looking at a few planets and some deep space objects like the ring nebula.

Edited by acem77, 15 May 2024 - 11:01 PM.

[Fivemileshigh]

There is also this:

 

https://www.apm-tele...tric-15x-barlow

 

I have one, it works well.

[acem77]

Thanks for the update, but knowing what I know now I am very happy with the linear bino viewer and it does not need any corrector. But this will be handy for people that still want to go this route.

There is also this:

https://www.apm-tele...tric-15x-barlow

I have one, it works well.

[CrossoverManiac]

I use the Siebert Optics 1.3x OCA for Dobs it fits into the focuser and attaches to the binoviewers with the option of a T2 thread or 1.25” opening. Also use the Williams Optics 2x Barlow for binoviewers as well. Still use both with conventional binoviewers and Dobs. Mostly now mostly use the linear binoviewers for deep sky with the Dobs.

 

Jim

 Wouldn't you use a higher power OCA to bring the focal plane further up from the focuser when fully retracted?

Edited by CrossoverManiac, 26 September 2024 - 12:59 PM.

[Bintang13]

Hi,

 

The Siebert 1.3x OCA works in all our Dobs. I believe that it contains two different lenses that together produces the 1.3 mag. I have a hard time merging eyepieces 10mm or less which makes the Siebert 1.3 less useful for planets, I can’t get past 130mag using 12mm eyepieces. We mainly use a 102 f11 refactor for planets using binoviewers. The Sieberts 1.3x works very well for low power DSO viewing in our 8” and 10” commercial Dobs. We use a low profile adapter from AstroSystems to get the binoviewers as close to the focuser as possible to reduce inwards travel as well as light weight eyepieces when not using the 1.3x Sieberts but when using barlows attached to the nosepiece.

I believe that your Newtonian is 250mm f4.8 1200mm focal length. If you have a strong focuser used to having stuff hanging from and have a driven mount, your considerations may be different than ours. I tend to work backwards driven by the eyepieces that I find work best for me and Judy for planets which are the 18.2 and 15mm Delites as well as 25mm Zeiss and Leica eyepieces. Our magnification for planets range from 150x to 200x at best. A Williams Optics 2x Barlow for binoviewers placed on the end of the binoviewers nosepiece with the 15mm Delites yield 160 mag, we use spacers to increase mag a bit if wanted. If we had a stronger focuser we would use our Sieberts telecentric Barlow which works like the TeleVue Powermats on the Dobs, they do provide a very slightly cleaner image which is my recommendation for you it should bring you to focus even with the filter tray. Also with a driven mount consider Takahashi TPL eyepieces which have narrow FOV, some consider them better than the 18mm LEs that preceded them. Lastly a Binotron 27 with filter switch and power switch would be the ultimate solution. We had used that prior but was too heavy for our setups. Please let us know what you end up doing. 
 

Jim

Edited by Bintang13, 27 September 2024 - 04:02 PM.

[Bintang13]

There is a great discussion on a prior CN thread titled Binoviewers and Powemates, ES Focal Extenders,barlows,Glasspathcorrectors - interesting combination - dated 02 Aug 2023 started by binoviewer expert denis0007dl it shows binoviewers attached to a Powermate. Past posts by Eddgie and our many other contributors are very worth checking out as well.

Edited by Bintang13, 27 September 2024 - 03:59 PM.