Fine tuning Baader Hyperion eyepieces.

[GazOC]

Baader are now selling "fine tuning rings" that fit inbetween the front Smyth/Barlow element and the eyepiece proper to increase focal length. The come in two sizes, 14mm and 28mm thickness.

Hyperion with 14mm Ring--28mm Ring-- 14 + 28 ring together.

21mm = 17.6mm, 15.5mm, 14.0,mm

17mm = 13.1mm, 10.8mm, 9.2mm

13mm = 10.8mm, 9.2mm, 8.1mm

8mm = 6.0mm, 5.0mm, 4.3mm

5mm = 4.0mm, 3.2mm, 2.6mm

3.5mm= 2.5mm, 2.1mm, 1.8mm

These will also fit the Orion Stratus range.

[Ambermile]

Does that affect the focus point though?

[GazOC]

I'd have thought so.

[The Warthog]

You always have to refocus when you put in a Barlow, anyway, so what odds? You aren't going to be changing these things real fast anyway, there'll be quite a bit of screwing to be done on them, so it will take a few minutes to change, and then you'll have to refocus. One of the ep manufacturers, Antares I think, makes a variable Barlow that works by sliding the lens up and down a tube. Same t'ing, eh?

[Ambermile]

Ah - but the dob only has about an inch of focus travel

[GordonCopestake]

1 inch!? Thats pooh. Out focus isn't a problem, but in focus could be

[Ambermile]

waddya mean, pooh? It's a CR1 and that's all I got.