41 replies to this topic

[Procyon]

Are these new?

http://maisonastrono...-of-telescopes/

[junomike]

Relatively new.  See here for more info.

[Procyon]

Will be a tough sell if binos don't bend, not sure If I've ever looked through a pair of binoculars or binoviewers while they're completed straight. With the 17.3mm aperture it could be great for someone with a dob, a pair of 17.3mm Delos and a head like spongebob maybe (maybe not). Got to admire any new product though.

Edited by Procyon, 21 April 2018 - 06:04 AM.

[Mark9473]

You're allowed to use a diagonal (just like with other binoviewers).

[junomike]

Will be a tough sell if binos don't bend, not sure If I've ever looked through a pair of binoculars or binoviewers while they're completed straight. With the 17.3mm aperture it could be great for someone with a dob, a pair of 17.3mm Delos and a head like spongebob maybe (maybe not). Got to admire any new product though.

In the link I posted above in post #2, you can see that these have sliding eyepiece collets (in/out) that adjust from 58mm - 74mm instead of conventional "bending".

[Jeff B]

Very interesting.  I like the idea of no additional back focus is needed (I imagine that's a result of the internal optics).  The weight is good too.  I wonder what the clear aperture is though.

 

Jeff

[Eddgie]

  I wonder what the clear aperture is though.

 

Jeff

17.3mm

[Procyon]

Are these new?

http://maisonastrono...-of-telescopes/

Just want to point out the price quoted in my link is in Canadian dollars..converts to $499 USD.

[B 26354]

Available directly from Orion, here in the US:

 

https://www.telescop...14/p/130300.uts

[Rusted]

Available directly from Orion, here in the US:

 

https://www.telescop...14/p/130300.uts

Okay at night in the dark, but the bright red locking rings might well be visible to peripheral vision in daylight.

Drawing ones head back to check the view will certainly provide a colourful shock to the system.

Call me old fashioned, but I prefer black around the eyepiece area.

[Jeff B]

17.3mm

Thanks Eddgie but...ugh.

 

Jeff

[Jeff B]

Okay at night in the dark, but the bright red locking rings might well be visible to peripheral vision in daylight.

Drawing ones head back to check the view will certainly provide a colourful shock to the system.

Call me old fashioned, but I prefer black around the eyepiece area.

Me too O.F.

 

But I still do like my old Silver Top Plossls...oh well.

 

The clear aperture is very small..  Interesting idea though.

[De Lorme]

 Any idea as to why they couldn't enlarge the clear aperture of the mirrors?

[Eddgie]

 Any idea as to why they couldn't enlarge the clear aperture of the mirrors?

Just a guess.   Optics are always a tradeoff, and probably the ratio between the mirror/prism size had to be reduced to allow the relay lenses to be able to give the necessary spacing to offset the light path.

 

Think about it this way. A William Optics type binoviewer has a light path of about 95mm and this is possible because the prisms are very small.   The small prisms limit the aperture.

 

In a Mark V, the prisms are much larger, but the light path is likewise much longer than the WO, being 123mm.

 

Of course I don't know the exact limit, but the bigger the prism, the longer the light path, and I am sure that it is a balance between the various components and the need to be able to exactly offset the path length of the binoviewer.

[DLuders]

Here is an official video about the new Orion Premium Linear BinoViewer:   https://www.youtube....h?v=N3nRpNf1R_Q      

[Sarkikos]

17.3mm

That's less than the clear aperture on my old Burgess Binoviewers, which have a CA of 22mm.  Not necessarily a deal breaker for me, because I only binoview planets and the Moon, never deep sky.

 

Mike

Edited by Sarkikos, 03 May 2018 - 06:36 AM.

[Zapp Brannigan]

I see they are selling a new diagonal to go with it, that keeps image orientation correct. 

 

https://www.telescop...al/p/130301.uts

[Sarkikos]

I see they are selling a new diagonal to go with it, that keeps image orientation correct. 

 

https://www.telescop...al/p/130301.uts

Actually, I'm more interested in the diagonal than the binoviewer.  So this isn't an Amici prism diagonal?  Or is it?  If there truly is no degradation in the image, I'd like to see a 2" version as well.

 

Mike

Edited by Sarkikos, 09 May 2018 - 09:57 AM.

[Timmo]

How will this linear bino compare against the existing folding binos, on an SCT, given its small 17.3mm CA?

[Jeff B]

That clear aperture is small but the design interesting and I'd like to hear some testimonials as to its actual use and quality.  It might very well be a nice, niche, high power viewer.

[CrazyPanda]

That clear aperture defeats the purpose of these binoviewers IMO. 

 

The zero light path design makes it possible to use them in a Newt without increasing the magnification via a barlow or GPC. Theoretically this means it would be possible for 24mm Pans to actually operate at 24mm focal length, rather than ~15mm with a 1.6x barlow attached to the nose.

 

But the small clear aperture means you have to use higher magnification eyepieces *anyway*, gaining you nothing (and in fact, limiting your options). 

 

At least with BVers with longer light paths but larger CA, you have the option to use 40mm plossls with little to no vignetting to bring magnification down and exit pupil up if your local seeing conditions or target justifies it.

 

The first company that comes out with 30mm CA, zero light path BVers with self-centering locks and dual diopters, will have a winner. 

[doug mc]

Doesn't one of the Siebert low power OCAs for binoviewers remedy this problem, at a much lower price?

[Eddgie]

Thanks Eddgie but...ugh.

 

Jeff

Well, you have to look at it this way.

 

If you have to use an OCA like the Siebert or Denkmeier, this would in essence reduce the clear aperture of a binoviewer with a 23mm clear aperture to 17.7mm.

 

So, let's say you are using a William Optics BV with a 25mm Plossl and you use a conventional BV with the Seibert optics 1.3x.  Now, your $200 BV with your $249 Siebert 1.3x, OCS costs you $550.

 

I you used this in a telescope with a 1000mm focal length and use a 25mm Plossl, you get 40x with a true field (assuming a 23mm field stop) of 1.32 degrees.

 

If you use the above BV (WO with Siebert 1.3x) you now have a the equivalent of 1300mm, so now the 25mm Plossl gives 52x with a true field of 1.1x.

 

If you used the linear BV with a 20mm Plossl, the focal lenght of the scope does not change, so assuming the field stop of the 20mm Plossl is 17.3mm, your power would be 50x (lower than the power of the WO with the 1.3x Siebert OCS) and the true field would be 1.14 degrees.

 

Given the cost of both approaches, it would appear then that the Orion Linear Binoviewer costs less a WO with the Siebert 1.3x OCS and offers about the same power and same true field.

 

Now you would say that you can get a wider field with a Denkmeier, but the marketing literature for Denk suggests a 1.3x low power, but this is not always achieved.   To get this power in a refractor, one needs to use the Denk (or similar diagonal) that allows the OCS to be attached directly to the front of the mirror box (CaChing).  With many dobs, the Newtonion extension tube needs to be extended to reach focus in low power and this raises the power across the power switch range. 

 

What this means then is that unless you have a binoviewer friendly telescope, the linear binoviewer's small clear aperture does not put it at any great disadvantage to other solutions, and it does it at a cheaper price than these other solutions.

 

And we know that the WO and similar require a 1.6x to reach focus (and often more than this) so to get a wider field than you can get with a non-BV ready scope is really difficult.

 

See, in the end, it is all a compromise, but the small aperture has to be taken in context that you can reach focus without having to amplify the focal length. Do the math and you should come to the same conclusion.   It is a geometry problem and just about any way you calculate it, to shorten the light path, you have to keep everything small (spacing, prism size, etc). 

 

I think it is a pretty solid idea.  

 

These would be outstanding with something like a pair of lightweight Nikon zooms (I have a pair).  The Nikons really only have an effective field stop of probably 16mm or so and I have seriously considered getting a linear BV for planetary observing and for solar use with my Mead 60.  I just want to hear quality reports before I take the plunge. 

 

So, while the clear aperture seems restrictive, it is going to give the same true field as most other approaches do, and it appears that it will do it in just about any scope without having to screw and unscrew a bunch of other optical elements. 

 

If the performance is good, I would choose these over the separate BV/1.3x approach.  Costs less, less hassle, same true field, same magnification.  

Edited by Eddgie, 12 May 2018 - 09:52 AM.

[Jeff B]

Good analysis Eddgie, but......

 

Most of my viewing is with refractors and most of them are "bino-friendly", and I've a couple of viewers with 28-30mm of clear aperture.  So, I can actually use the pair of 35mm Ultimas that you suggested a while ago with minimal vignetting and the widest possible TFOV available in the 1.25" format.

 

Even with my newts, I've short adapters that let me use these viewers and eyepieces with my Denk OCS/power switch newt system.  The lowest power switch setting is ~1.3X and at that setting I don't care if there is a little intrusion of the OCS into the light path.

 

But that's why I say these new viewers could be a really cool niche product for higher power, smaller FOV viewing, like for solar system stuff or even double stars.  I would not have to fuss around with the OCS system when using it with a newt or Mak 

 

Jeff

[Eddgie]

Yes, I don't know anyone that would buy these for use in a binoviewer friendly scope but many people have existing scopes that are not BV friendly.

 

Now anyone that has followed my post will know that my standard advice it to skip all of these other approaches and just go directly to a Denk or Earthwin power switch system because it is more flexible, offers a wider field of view, and turns one good pair of eyepieces into three, so in the end, does not cost more than a system like this one.

 

And that would still by my advice, but I can see a unit like this being used in something like My Meade 60mm H-a solar scope because it is compact and light and there is no way to use a 1.3x OCS.   Dob users that just want to use if for planets might find it appealing too. 

 

For most people and most applications though, I always recommend power switch type systems. 

 

We'll see if it succeeds in the marketplace.   I would rather have this though than a new WO and a $250 OCS.  

 

(Most people though don't realize the huge sacrifice in true field until after they have purchased the WO, and then they look to supercharge it and then buy an OCA, so this is why I think the Linear system may not find broad acceptance in the marketplace.   Knock $100 off though, and I suspect they would sell quite well.).