Types of viewfinders

[BlueWind]

Hello: I apologize for the very basic nature of this question. What is really a Newtonian viewfinder and what is a Galilean viewfinder? All the information on this topic will be welcome (definitions, links, etc).
Thanks in advance
JF

 

[Marco Gilardetti]

Galileian type uses lenses, it's a reversed telescope. It's a refractive device.

Newtonian should use mirrors (at least partially, or in the form of prisms) . It's basically a reflective device.

 

[BlueWind]

Thanks a lot, Marco, for your answer.
Regards
JF