ATM TERMINOLOGY - C

 

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COC:

Center Over Center, a stroke used during grinding in which the tool and mirror center pass over each other. Often accompanied by the amount of (total) travel in parts of the mirror diameter. (I.e. the distance between the two centers is never more than half of the value)

 

COE:

Center Over Edge, a stroke used during rough grinding to quickly remove glass. The center of the mirror (MOT) is moved in parallel to the mirror edge (1/6 diameter).

 

Collimation:

A scope is said to be collimated when all optical elements share the same optical axis. In a Newton, only the (paraboloidal) primary mirror and the eyepiece have an optical axis. Note that the secondary mirror does not have an optical axis. Confusingly this term is also used to include alignment.

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