Have a look at
http://www.televue.com/engine/TV3b_p...d=52&Tab=_back
and then
http://www.televue.com/engine/TV3b_p...d=53&Tab=_back
and a picture of the Clave Barlow at
https://commons.wikimedia.org/wiki/F...arlow_lens.jpg
I would recommend getting the Tele Vue 2x as it is still in production and stay away from Shorty types. The Shorty Plus is supposed to be better than the shorty and perhaps an attempt to mimic the Klee but I have never used any 'short' Barlow other than a friends Klee briefly so cannot comment on their pros and cons. I can say the the Clave and Tele Vue 2x and 3x work very well as do the Powermates with the latter having the advantages mentioned on the Tele Vue web site.
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