Binoviewers with Newtonians

[abberation]

I have considered getting a binoviewer for use with my dobs.  I have heard that they are tricky to use with Newtonians but why I don't know. Is anyone using them in this configuration? If so how do you get on with them, I would like to hear.

Richf

[Laurie61]

The bino viewers increase the light path between focuser and eyepiece's and many newt's don't have enough IN focus movement to compensate. With solid tube scopes one way to get around this is move the primary mirror up the tube by the necessary amount. Truss tube scopes can be used not fully extended which has the same affect as above. 

[SimonfromSussex]

I use a revelation binoviwer with my 16" dob and think it is excellent!

I use it mainly on the moon and planets but it is also very good on globular clusters and small planetary nebula.

Focus is an issue, I have two 25mm eyepieces in it and then use either a x2 or x2.5 Barlow to make it work. I think it's giving me about the equivalent of a 7mm & 5mm eyepiece respectively.

I also use them on the sun through my lunt and proms look really great!

For me they give a 3d experience but they don't suit everyone. Rustysplit has tried them and his eyes don't get on with them at all.

If you can see ok in both eyes I'd say they are well worth a go.

[moriniboy]

The WO binoviewer has a barlow included in the package, this will enable you to get focus with the vast majority of scopes.

It worked well with my 200PDS and Orion VX6L.

[rikroe666]

Good to hear that moriniboy!  

I've just bought a WO binoviewer off abs to try in my scopes, its not come yet but hopefully tomorrow. 

abberation i will let you know how i get on if the clouds ever clear. 

[abberation]

Thanks all for the replies.

I'm getting on a bit and my eyes have seen better days so I reckoned a bino viewer would be helpfull.

The replies have been encouraging so I'll probably  get one with the 2" 2x barlow and 20mm ep's.

Rilroe666, please let me know your experience!

[rikroe666]

Yes i will let you know,

I read a lot of stuff about using these with newts but they seem to work in some scopes and not others so thought best to just try them and if they don't work i will just sell them on.

[Merlin]

I have a WO binoviewer ( plus a couple of homemade ones ) with the supplied 20mm eyepieces. For a Newtonian, 25mm eyepieces are better, as we save 5mm on in-focusing, which can make all the difference.

[rikroe666]

My William Optics binoviewers turned up today, obviously i cant try them at night as its always cloudy

so i tried them on a house a few miles away, without the 1.6 barlow thing in the 130pds didn't have enough in focus but with it screwed to the end i had over half inch left after it had focused so very happy

I reckon the 200pds will be fine also as i need to use a barlow as a spacer with no lens in to achieve focus with just an eyepiece in as there isn't enough back focus. Might not even need the barlow thing, or is that just wishful thinking?

[abberation]

Sounds very encouraging, and I would like to hear how it goes with clear skies. Think I will take the plunge and get one. It had been suggested that I use a 2" barlow. Is there any advantage for this does anyone know?

[Avocette]

The WO Binoviewer kit comes with the 1.6x nosepiece Barlow as standard and I have also used it with a 1.25" 2x Barlow with success on a fixed tube 250p Dob. There is a natural field stop limit in the prism optics which means the apparent field of view matches well with the supplied 20mm 66 degree WO eyepieces or for instance two SW 25mm 52 degree 'Super Plossls' but anything longer would not give you more view of the sky, just less magnification. A 2" Barlow would be no advantage. I like to use longer focal length eyepieces so am happy that I can shorten the trusses of my 300p Flextube Dob by 10cm and so reach focus without any Barlow. But since the 300p has a focal length of 1500mm, the magnification is already 1.25x that of the 250p/1200mm solid tube Dob.

[abberation]

The WO Binoviewer kit comes with the 1.6x nosepiece Barlow as standard and I have also used it with a 1.25" 2x Barlow with success on a fixed tube 250p Dob. There is a natural field stop limit in the prism optics which means the apparent field of view matches well with the supplied 20mm 66 degree WO eyepieces or for instance two SW 25mm 52 degree 'Super Plossls' but anything longer would not give you more view of the sky, just less magnification. A 2" Barlow would be no advantage. I like to use longer focal length eyepieces so am happy that I can shorten the trusses of my 300p Flextube Dob by 10cm and so reach focus without any Barlow. But since the 300p has a focal length of 1500mm, the magnification is already 1.25x that of the 250p/1200mm solid tube Dob.

Thanks for taking the time to answer - very informative especially about the 2" Barlow.