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Binoviewer Linear eyepieces

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#1 titanio

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Posted 19 April 2024 - 11:42 AM

Hi everyone

 

Linear Binoviewer,  mine is TS but for other branches you can use same eyepieces. I use it in MN 86 Maksutov Newton f6.

 

Use it only for deep sky, better with  reflector telescoes , you can use also it in refractors but for me it works better with reflectors, and you can see real view not invert observation, so you can use your reflector in terrestrial observation. Do not complicated your life too much with eyepieces, use only two o three maximum plus kasai 0.66x  reducer. I tried a 0.5X reducer but it did not work.

 

 

From my point of view with the 18 TAO is enough, you can use also the BCO 18 or fujiyama 18, if you want less power and more field of view you can use the kasai 0.66X reducer in from of the bino, you can use also an ortho 25, but better if you have the kasai  reducer 0.66x it will be enough. For much power use a 15 mm ploss or a 12.5 ortho.

 

This bino works also for lunar observation you will see the full moon, for instances with a newton 200 f6 using 18mm orthos or 25mm orthos.

 

This Linear bino is perfect for deep sky because it works like if one   did not have a binoviwer, for instance what you see with one eyepiece you see with the linear but your observation is with two  eyes. For planetary better to use the traditional benoviewers.

 

Greetings

 

Toni

 

 


Edited by titanio, 19 April 2024 - 12:13 PM.

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#2 titanio

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Posted 21 April 2024 - 06:06 AM

Hi again, 

 

I can see how well but only in astronomical observation TS 19 Flat Field eyepieces perform as well as the ED 18 Flat eyepieces. In day observation one can see that they vignetting a bit and you can see a blue ring, but at night you do not se any problem, these eyepieces work very well and you do not see any vignetting although they lost a little of field instead 65 or 60 they have around 58.

 

To know if your eyepie will  vignetting, as Kasai says use formula:  V= Eyepiece focal length X eyepieces field.

If you get less than 1000 you do not have vignetting.

 

18×60 = 1080. Here the vignetting is not too much but there is.

 

 

Greetings

 

Toni

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Edited by titanio, 21 April 2024 - 07:35 AM.

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#3 titanio

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Posted 21 April 2024 - 02:33 PM

Hi,

 

Today from Spain the moon observation with intes micro mn86 using a linear TS binoviewer with several eyepieces, among them TAOs18 ,TAOs 25, Fujiyama ortho 12.5  and Svbony zoom 3-8 very nice views and the more important I did not see any reflexion. I also observed the moon at 406x using the zbvony 3-8x zoom without not problem. I did not used any barlow or reducer.  I compared also the linear binoviewer to the Baader Maxbright binoviewer  but to make focus and to see the full moon I needed to put a 1.8x TMB from APM barlow,  and two 40 mm eyepieces and a power swich in the lower configuration  from Denkmeier, also nice view but easier to use the linear at least if I want to see the full moon.

 

I think for Jupiter observation with linear binoviewer the views wont be so nice but  maybe it gives me a surprise.

 

To know this I have to wait for next planet sessions.

 

 

Greetings

 

Toni


Edited by titanio, 21 April 2024 - 02:46 PM.


#4 titanio

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Posted 29 April 2024 - 03:14 AM

Hi,

 

Last night I was able to observe with the linear using the Kasai 0.66x focal reducer. I can tell you that this focal reducer should be included with the linear binoviewer or who buys a linear bino should buy it without hesitation, once  threaten it to the bino you do not need to take it off,   it  reduces the focal power factor and expand the field of view,  taking this  into account you can use a 12.5 mm eyepiece as if it were a 20 mm or an 18mm eyepiece as if it were a 27.5 mm or a 25mm as if it were  a 38 mm. Last night I used  the 18 and the 25 mm TAOs with the linear and the Kasai reducer with an MN 200 f6. For me the 18 mm (TAO) with the linear and the reducer 0.66x is perfect and with this configuration they are my favorite eyepieces. The 25 mm (TAO) is ok but I prefer the 18mm eyepieces.

 

 

I think also the Fujiyama 18 mm and BCO 18 mm must be great eyepieces for this configuration.

 

 

 

Greetings

 

Toni


Edited by titanio, 29 April 2024 - 03:19 AM.

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#5 Takuan

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Posted 29 April 2024 - 08:45 AM

Hi,

Last night I was able to observe with the linear using the Kasai 0.66x focal reducer. I can tell you that this focal reducer should be included with the linear binoviewer or who buys a linear bino should buy it without hesitation, once threaten it to the bino you do not need to take it off, it reduces the focal power factor and expand the field of view, taking this into account you can use a 12.5 mm eyepiece as if it were a 20 mm or an 18mm eyepiece as if it were a 27.5 mm or a 25mm as if it were a 38 mm. Last night I used the 18 and the 25 mm TAOs with the linear and the Kasai reducer with an MN 200 f6. For me the 18 mm (TAO) with the linear and the reducer 0.66x is perfect and with this configuration they are my favorite eyepieces. The 25 mm (TAO) is ok but I prefer the 18mm eyepieces.


I think also the Fujiyama 18 mm and BCO 18 mm must be great eyepieces for this configuration.



Greetings

Toni


The Kasai reducer doesn't come to focus with my 10" dob. It worked fine with my 6" f5 Newtonian, on the other hand.

..just notice.
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#6 Bintang13

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Posted 29 April 2024 - 09:22 AM

Hi Takuan,

 

The Linears and Kasai reducer came to focus in all of our Dobs 8”, 10”, and the 12”. If I remember correctly it might have needed some additional out travel of the focuser. Maybe an extension would do the trick. 
 

Jim


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#7 Takuan

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Posted 29 April 2024 - 11:16 AM

Hi Takuan,

The Linears and Kasai reducer came to focus in all of our Dobs 8”, 10”, and the 12”. If I remember correctly it might have needed some additional out travel of the focuser. Maybe an extension would do the trick.

Jim


In fact, if I remember correctly, there was a lack of inward focus. So I couldn't fix it with an extension tube.
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#8 Bintang13

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Posted 29 April 2024 - 11:36 AM

Hi Takuan,

 

Yes, you are right. I did not remember that correctly. I use a type of in travel adapter to seat the linears for more stability that is probably why I am reaching focus. Also the 8 and 10” Dobs are Orion and the 12” is Apertura. Sorry to confuse.

 

Jim


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#9 Bintang13

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Posted 29 April 2024 - 11:44 AM

Image of my setup.6E6551F1-F909-4C3D-8450-C16778358E45.jpeg


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#10 titanio

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Posted 29 April 2024 - 01:04 PM

Hi 

 

Mine makes focus without any problem in my Maksutov Newton mn86. As I said before the linear is a benoviewer perfect for Newtonian telescopes. With the kasai reducer 0.66x it needs a few intravel  but no too much. 

 

I have not used the kasai reducer  in my other telescopes yet, a TS ED 102 f11 which I use without any glass path and in my Maksutov Gregory  24O which I use also without any glasspath and I use  in planetary observation with binos or  in monovision for deepsky. For those telescopes the Baader Maxbright  and the Zeiss bino are perfects.

 

In the maksutov Newton which I use also for planets with a Baader Maxbright plus 1.8x barlow, but for deepsky better to use the linear bino with the kasai 0.66x reducer.

If I want to use the Baader Maxbright in deepsky with the mn86 I use a pair of 40 mm or 32 mm eyepiece,  the barlow 1.8x plus a denkemeier power swich  in its lower configuration.  With the linear  at least in deepsky observation everything is easier for me.

 

Greetings

 

Toni


Edited by titanio, 29 April 2024 - 01:15 PM.

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#11 titanio

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Posted 29 April 2024 - 01:24 PM

Here is the Baader Maxbright for deepsky configuration in my mn86. Om top is the barlow threatened.. Only with this configuration is possible to see a full moon. With the linear bino with or without the kasai reducer and using a 18 mm eyepiece I see the full moon. 

 

 

 

Greetings 

 

Toni

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Edited by titanio, 29 April 2024 - 01:33 PM.


#12 Sarkikos

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Posted 11 May 2024 - 07:32 AM

A picture is not always worth a thousand words.  grin.gif

 

Please tell us exactly what you have attached to the binoviewer, and provide a link where it can be purchased.

 

Mike 


Edited by Sarkikos, 11 May 2024 - 08:06 AM.

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#13 Sarkikos

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Posted 11 May 2024 - 07:54 AM

Earlier this year, I started a thread on the linear binoviewers.  At first, I wanted to purchase the Orion version, but they kept delaying availability.   Finally, I bought the StellaLyra from FLO. 

 

I tried to determine which eyepieces would work best in the linears.   My main purpose was to avoid vignetting. 

 

https://www.cloudyni...s-or-no/page-2   

 

Read my post # 120 for a good example of how not to look for vignetting.  grin.gif   I found out that it's difficult to determine if a specific pair of eyepieces vignette when you are observing deep sky objects at night.  There is no obvious indication of vignetting when just looking through the eyepieces in the binoviewer.  

 

My post # 141 explains a simple, easy way to detect vignetting with specific eyepieces in a binoviewer without even leaving your house.  You could also use the Kasai Formula, which I think will get you close to the same results.  But nothing beats seeing it for yourself. 

 

In post # 148, I tested a number of eyepiece pairs for vignetting inside my house, using the simple method.  Here are the results:

 

28 Edmund RKE (23.3mm field stop):  AFOV obviously narrower through linears.

26 Celestron Silver Top Plossl (22.5mm field stop):  AFOV obviously narrower through linears.

25 Sterling Plossl (23.2mm field stop):  AFOV obviously narrower through linears.

24 Brandon (21.4mm field stop):  AFOV obviously narrower through linears.

8-24 Baader Hyperion Zoom Mark III (17.6mm field stop):  AFOV the same size through linears as through eyepiece held in the hand.

 

I also tested my bino pairs which had field stops between the 21.4mm of the 24 Brandon and the 17.6mm of the Baader Zoom:

 

20 Photo-20 (from a couple baby Maks, 20.1mm field stop):  AFOV's the same size.

25 Celestron Plossl (black with orange letters, 21.1mm field stop):  AFOV obviously narrower through linears.

Orion Explorer II Kellner (21.1mm field stop):  AFOV obviously narrower through linears.

Sky-Watcher LET/LER (21.2mm field stop):  AFOV obviously narrower through linears.

 

From these results, I'd say that if you want to avoid vignetting with the linear binoviewers, don't use eyepieces with field stops any wider than about 20mm.  At 21mm, you've already gone too wide. 

 

The Baader Zoom looks like an interesting all-around eyepiece for the linears.  You have a range between 8mm and 24mm.   More if you use a Barlow or reducer.   And they don't vignette!   

 

Now I'm sorry I bought a pair of the Mark III's years ago.  I only have one Mark IV, which is designed to be more ergonomic for binoviewers.  Maybe I should sell the Mark III's and get another Mark IV?  On the other hand, the Mark IV is even less parfocal than the Mark III's.  (Not parfocal = you have to refocus when zooming.  At least I have to.)

 

Mike


Edited by Sarkikos, 11 May 2024 - 08:03 AM.

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#14 Bintang13

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Posted 11 May 2024 - 10:42 AM

Hi Mike,

 

Please don’t tell me a picture is not worth a thousand words it took this neanderthal  20 minutes to figure out how to post it. In the image the Orion Linear Binoviewers are smartly outfitted wearing an AstroSystems Ultra low Eyepiece Adapter which can be found at astroystems.biz. 
 

Jim


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#15 Sarkikos

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Posted 11 May 2024 - 10:48 AM

Hi Mike,

 

Please don’t tell me a picture is not worth a thousand words it took this neanderthal  20 minutes to figure out how to post it. In the image the Orion Linear Binoviewers are smartly outfitted wearing an AstroSystems Ultra low Eyepiece Adapter which can be found at astroystems.biz. 
 

Jim

For me, words are easier.  I only post a pic as a last resort.  :grin:

 

Mike


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#16 Bintang13

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Posted 11 May 2024 - 11:24 AM

There was a prior topic on in-travel adapters on CN titled Tele Vue In-Travel Adapter - setscrew or how does it hold eyepiece? dated 13 Mar 2021. Starman 1 in particular goes into very informative detail regarding differences and uses.


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