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4" Eyepiece


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Found this advert...




This is an odd specification.

I calculate that if it actually is a 100mm focal length 80 degree eyepiece, it would have a 140mm field stop, so would not fit into a 4" barrel.


Perhaps it can actually be opened up to expose the full 140mm diameter field stop assuming someone has a big enough focuser.


Maybe the 100mm written on top of the eyepiece in one of the photos simply means it fits a 100mm (4") focuser. If so, it would have a focal length of about 70mm at an 80 degree apparent field.


It might be useful as a doorstop. :lol:


Here it is next to a 31mm Nagler :o ...




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Sheila has a 4" focuser  :rolleyes:

3 1/2 i think Eddy......  but look as though it might fit :o


ooops yes apparently mine is a 4" focuser :o

Edited by Sheila
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