Best Orthos to use with Binoviewer for Planetary/Lunar Observations with an Apo Scope?

[paulastro]

43 minutes ago, YKSE said:

Paul,

I don't know how flexible your barlow is, if it somehow can be placed in front of the diagonal, then you'll get much higher barlow effect.

The 2.6x GPC is only 2.5x when placed directly in front of the binoviewer, it becomes 4.7x when placed in front of the 2" prism diagonal as in the picture.

 

Many thanks.  Yes, I could put my barlow (it's x2)  in front of the barlow, but I'm looking to reduce the magnification, hence I'm looking for something like a pair of 19mm to 21mm Orithos - which of course no-one makes any of this focal length as far as I know .  Of course I'm aware of the many 18mm Orthos but they are too close to the 16.8s I already have.

This is probably a daft question, but are there any GPCs available for my Baader Maxbright Binoviewer?  It would be great to have the flexibility you have with the setup you use, but I can't afford to buy another binoviewer.

[mikeDnight]

You could always sell that DL thingy and buy a DC. That would give you the slightly lower power you're after.

I'm here to help!  

[YKSE]

36 minutes ago, Stu said:

Do GPCs not correct for CA caused by the Binoviewer prisms as well?

Yes, I think the more exact term here is spherochromatism, it's CA induced by binoviewer's prism.

[YKSE]

10 minutes ago, paulastro said:

This is probably a daft question, but are there any GPCs available for my Baader Maxbright Binoviewer?  It would be great to have the flexibility you have with the setup you use, but I can't afford to buy another binoviewer.

TS here lists it as next delivery

http://www.teleskop-express.de/shop/index.php/cat/c60_Binocular-Viewers.html

you might drop them a mail to check.