Optics/Physics question (Hyperion eyepieces)

[Darryls]

I have some Baader Hyperion eyepieces that I use with my DSLR and an Intes 6" Mak-cass.  (The camera is coupled to the eyepiece with a T-thread adapter). In order to get it to focus, I have to add about 5" of extenders between the eyepiece and the focuser!  If I add a T-extension between the camera and the eyepiece, will that reduce significantly the total "inches of extension" required?

[Macavity]

Wot, no replies?  Risking wind and limb, I will try...

I sense you are trying out Eyepiece Projection?

(For which Baader Hyperions are advertised)

I'm just revisited this with a view to documenting the

various configurations etc. (A major change for me)!

My (experimental) findings (conformable via theory):

Eyepiece projection... requires the eyepiece to be

racked out significantly towards the observer and

beyond the normal position for visual observation. 

(May not be terribly convenient for Newts etc.)

Adding extra T2 extenders behind the eye lens will

certainly increase the "magnification" - Will effect

the in / out focus. But it won't significantly reduce 

the typical extension required to achieve focus.

The technique may still be useful, I sense...

Catadiopteric systems (SCT's, Maksutovs etc.)

have much greater range of in / out focus etc.

Edited February 7, 2015 by Macavity

[Owmuchonomy]

Aaah yes.  I use an 8mm BH for planetary EPP with my D60.  It works ok on my 9.25 SCT due to the huge focus range on tap.  With my frac it is easy to see the amount of focusser movement required.  I have to draw the focusser out to 90mm of back focus to get it to work.