Teleview 2" Big Barlow - measurements (subs for 50mm extension?)

[NickK]

I'm just thinking about a barlow for imaging. Can anyone provide the measurements of the barlow?

At the moment I have a 2" 50mm extension tube and I was thinking if it could be substituted with a barlow (2x).

[brantuk]

The 2" Big Barlow wieghs 250g, stands 120mm high and has a 55mm diameter at the top

[NickK]

Thank you brantuk - do you know the size when inserted into the optic train? I'm assuming the 120mm is with the 2" tongue - I'm assuming that it will be about 80mm.

Unfortunately the focus point is about 10mm of focuser travel form full retracted position so I'm looking at as close to 50-55mm.

[brantuk]

Yes it's the full height as it stands - hang on and I'll get you the 2" tongue size

Edit : it's 65mm

[NickK]

Ok, so it's

[FONT="Fixedsys"]
oooooooo
------------[========]
[<65mm>][<- 55mm->]
------------[========]
oooooooo
[/font]

where 'o' is the telescope, '-' is the tongue and '=' is the body of the barlow.

Hmm.. it's one in a million chance but it might just work

[brantuk]

Yup - the 65 mm bit is the bit you insert into the focuser tube