Binoviewers on Dobs

[Applemac]

Can Binoviewers be used on a Dobsonian, I like the idea of what they do and can imagine they are comfortable to use. But are they a viable option on a dob? Mines an F5 12" dob. Thanks

[LukeSkywatcher]

I cant think of any reason why not. If they fit into the focuser of the "Dob" then they can be used.

[Andrew*]

Binoviewers eat up tons of focus travel, so almost all newts will not have enough back-focus for a native binoviewer. However, many binoviewers have add-on barlow lenses to gain back focus at the expense of extra magnification, preventing low-power views.

The best newt binoviewers I know of are Denkmeier - the newtonian OCS system for the standard model only magnifies 1.4x and focuses where a normal eyepiece would. I have heard of another make that only magnifies 1.2 or 1.25x but I can't remember which...

Beware of budget binoviewers that have a "1.6x" barlow - it's 1.6x when screwed directly onto the eyepiece, but when screwed onto the binoviewer, how it's intended to be used, the magnification is actually 3x because of the increased distance between the barlow and the eyepiece.

Andrew

[JAO]

Applemac

Binoviewing with a dob depends on whether you have enough back focus on your scope to allow the Binoviewer to come to focus. This will often mean using a barlow or with Premium Binoviewer a Glass Path Corrector or Optical Corrector

I have to say that I use a Binoviewer on my Mak for planetary and lunar observing but I prefer single eyepiece views in my dobs for DSOs.

That is just my personal view though and I am sure others will offer different perspectives.

The link below shows a Newtonian optimised Binoviewer setup:

Denkmeier - Deep Sky Binoviewer: The New Super Systems

Adrian

Edit: Andrew beat me to it!

The other Binoviewer that Andrew might be referring to is the Baader Mk V, not to be confused with cheaper Baader units. The Mk V is more expensive that the Denkmeier II HTH

[Andrew*]

At least we agree!

1.3x for the mk. II - even better!

I have a pair of revelations, and in my 12" dob the lowest magnification I could get using the "1.6x" corrector is 136x with a 40mm 40° eyepiece.

That's why I got a pair of Denkmeiers and they're fantastic

Andrew

[JAO]

Andrew

Snap!

I had a pair of Revelations, they were OK but I now have a pair of Denks and they are just superb, a different league. I did look at pair of MK Vs but needed a mortgage for them once you buy the Glass Path Correctors for two scopes!

Adrian