I have just received a 4" hypochromat today made by John Wall himself.
It is not a coincidence if the topic title looks like the one used for the Zerochromat.
John Wall is a brillant UK optician, inventor of the crayford focuser and the retrofocal dialyte system that Peter Wise used to make the Zerochromat refractor.
If the Zerochromat is in the upper level of the refractor family, the Hypochromat is on the other side.
It can be seen like a RFT telescope, used for the same targets as the fast achro refractors (comet finder) but much cheaper (thousand of $ for an 250mm achro vs a few hundred $ for my 250mm hypo, see atm forum).
The Hypo's philosophy is to make a very cheap, fun and easy to build refractor.
Like the Zerochromat, the Hypo use a thin single lens made from ordinary crown glass followed by a reduction less assembly made with one or two smaller achro objective (50mm binocular glass).
Typical powers are X20 to X50, depends of the OG focal lens.
More to come
Edited by meade4ever, 02 October 2014 - 11:16 PM.