Jump to content

1564402927_Comet2021Banner.jpg.a8d9e102cd65f969b635e8061096d211.jpg

Binoviewers in a dob.


paul mc c
 Share

Recommended Posts

ive read a few thread from people who have/do use them but quite a few seemed to have focusing problems and either had to fit a spacer or remove one to get it to work properly.do a search and im sure there will be a few threads or someone will be along in good time with their experiences

Link to comment
Share on other sites

In a thread about a month ago, someone had discovered that there are extra holes on the truss rods of the latest SW 300p flextube Dobs. These seem to be for shortening the secondary to primary mirror distance by 110mm which exactly compensates for the needed back-focus of some typical binoviewers.

Link to comment
Share on other sites

In a thread about a month ago, someone had discovered that there are extra holes on the truss rods of the latest SW 300p flextube Dobs. These seem to be for shortening the secondary to primary mirror distance by 110mm which exactly compensates for the needed back-focus of some typical binoviewers.

Yes i read that on CN forum,SW will probably bring out thier own binoviewers now.

Link to comment
Share on other sites

In a thread about a month ago, someone had discovered that there are extra holes on the truss rods of the latest SW 300p flextube Dobs. These seem to be for shortening the secondary to primary mirror distance by 110mm which exactly compensates for the needed back-focus of some typical binoviewers.

Now that is a good idea. From what I've read, though, the secondary will vignette the light cone if the primary is, in effect, moved closer.

Some people replace the secondary with a smaller one to overcome this. I've no practical experience of this however.

But when properly set up, I think a 300 Dob is one of the best bino platforms, re aperture/FOV/ergonomics etc.

Link to comment
Share on other sites

Now that is a good idea. From what I've read, though, the secondary will vignette the light cone if the primary is, in effect, moved closer.

Some people replace the secondary with a smaller one to overcome this. I've no practical experience of this however.

But when properly set up, I think a 300 Dob is one of the best bino platforms, re aperture/FOV/ergonomics etc.

it would need to be a larger secondary, not smaller. I doubt the benefits would be worth it though and your existing secondary might be just big enough if as most are, it is slightly oversized.

Link to comment
Share on other sites

it would need to be a larger secondary, not smaller. I doubt the benefits would be worth it though and your existing secondary might be just big enough if as most are, it is slightly oversized.

Thanks for the correction, Moonshane, [i was thinking that was the case as I wrote it].........it probably doesn't make a huge difference but I read that on CN where some of the Bino nuts work at mm's of tolerance :-)

Link to comment
Share on other sites

Has any one used binoviewers in a dob and if so is there any mod that need done to the scope and are they recomended.

I would be using them in a 12'' f5.3 scope.

Thanks Paul.

I have used a bino viewer with my OO scope, you do need to remove the spacer. My revelation bino viewer does not need a barlow to focus. Although my scope is f 6 I left OO to fit an appropriate sized secondary and standard focal position when ordering the scope. So I would think your OO scope should work OK without any mod's :smiley:   

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.