Baader Hyperion zoom - difference between Mk2 and Mk3

[Mark at Beaufort]

I just put in my Hyperion Mk2 zoom into my new Skywatcher binoviwers using my 4" APO frac. Well I can obtain focus which is the good start. I am now thinking of using 2 Baader zooms so that I don't need to change EPs.

Clearly two things I need to think about -

• The Hyperion is slightly wider than normal EPs so will I get my nose in between the gap? - By the way my nose is not that big .
  
• Clearly my zoom is a Mk2 which means unless I get lucky with the S/H market I need to buy the Mk3. Well is there any real difference between the two? Will they be parfocal?
  

Has anyone had experience using the Hyperion zoom in binoviewers?

Any views would be appreciated.

Mark

[Andrew*]

Hi Mark,

I've used two Mk.3 zooms with great success in my Denkmeier binoviewers. My IPD is about the minimum required though - any less and the eyepiece bodies will touch, but I do have a very narrow face.

You'd need to remind me the design of the Mk.2s, but I wonder if they are too large for ones nose not to get in the way. The Mk.3s have the option to remove the larger eyecup for exactly this purpose - underneath is a smaller eye cup to which you attach an additional rubber ring. However, your particular anatomy may allow it anyway!

While the two versions are very similar, I would not bet on them being similar enough for binoviewing. They may have slightly different heights, which is very awkward in use. Or they may not be parfocal, which amounts to the same thing.

So two Mk.3s may be the only way to go...

Andrew

[Mark at Beaufort]

Thanks for that Andrew. I had a feeling that you had used zooms in binoviewers in the past so perhaps we may have chatted about it at one of the SGL star parties. I think your advice is spot on so perhaps I might sell my Mk2 and either buy 2 Mk3s or alternatively two zooms with slimmer bodies.

Andrew if you have experience on any other zoom which is good with binoviewers then please let me know. That request goes to anyone on the forum with this experienceas well.

Mark