WO Binoviewer: EPs + Barlow?

[Raph-in-the-sky]

Hello,

I just bought a WO bino. It came with the x1.6 barlow and I have a x2 Celestron Ultima Barlow. I intend to use the bino on a Skywatcher 10' fulltube dob (So I will have to use it with one of the barlows)

My question is: will the x1.6 barlow give x1.6 and will the x2 Barlow actually give x2?

And which EPs would you go for with such a set up?

Cheers,

Raphael

 

 

 

[Franklin]

You'll need to use the x1.6 WO barlow to get focus. There won't be enough in-focus to use without it. It will give x1.6 when used on the bino nosepiece to your eyepieces. Your x2 Ultima on the bino nosepiece will give more than x2, more like x3, a bit like putting a barlow before a diagonal rather than on the eyepiece. You may need to get an extension if your focuser travel is not enough. 

I got a WO bino viewer but I use it on a refractor which has a split tube so I can reduce the length of the tube and use the bino's without any barlow or GPC. It's a bit of a faff but definately worth it for the 3-dimensional effect of bino-veiwing. 👍

[Franklin]

PS. The WO bino's will vignette with eyepieces over about 20mm.

[Franklin]

PPS. The WO 20mm 66deg pair work really well and I also use a couple of Baader 10mm BCO's for higher power.

[Raph-in-the-sky]

1 hour ago, Franklin said:

PPS. The WO 20mm 66deg pair work really well and I also use a couple of Baader 10mm BCO's for higher power.

Do you think goldline plossl (also 66°) would do well in this set up? How about the Skywatcher planetary? I'm looking for a cheap option

[Franklin]

Yes definately they would work well. But if you use eyepieces with a focal length longer than about 20mm, they will vignette in the WO bino's. Still work but you won't get the full field of view. This is because the WO bino's have an inside clear aperture of around 21mm. 

[Raph-in-the-sky]

11 minutes ago, Franklin said:

Yes definately they would work well. But if you use eyepieces with a focal length longer than about 20mm, they will vignette in the WO bino's. Still work but you won't get the full field of view. This is because the WO bino's have an inside clear aperture of around 21mm. 

What do you think of these? https://www.amazon.fr/Svbony-Oculaires-Astronomique-Accessoires-Asphérique/dp/B07TVJC5KR/ref=sr_1_3?__mk_fr_FR=ÅMÅŽÕÑ&dchild=1&keywords=svbony+20mm+oculaire&qid=1629045025&sr=8-3

[Franklin]

Yes, Svbony are a good budget option and the 20mm 65deg would be optimum in the WO bino's. Your 250px is 1200mmFL so you would be getting 96x with the 1.6x barlow and at 65deg AFOV that would give a 0.67deg FOV. Big enough to show the whole disk of the Moon in 3D! 

[Franklin]

Hey Ralph, I see you are in Brussels and just remembered that ASTROBOOT have on their Euro site the William Optics 2x Barlow bino-nosepiece @ 24euro. Would give you an extra power and it's the dedicated one for the WO bino's.

I really wanted to get one for mine from them but they have stopped trading to the UK because of all the Brexit nonsense. 😪

[Raph-in-the-sky]

57 minutes ago, Franklin said:

Hey Ralph, I see you are in Brussels and just remembered that ASTROBOOT have on their Euro site the William Optics 2x Barlow bino-nosepiece @ 24euro. Would give you an extra power and it's the dedicated one for the WO bino's.

I really wanted to get one for mine from them but they have stopped trading to the UK because of all the Brexit nonsense. 😪

Thanks for the tip. I'll have a look!