What is the object distance for a concave mirror?

[ccflyer]

Hey eveyone,

I have a concave mirror and an object x distance away from the mirror. I am wondering if anyone knows where you measure from in order to determine how far away the object is from the mirror. Is it from the object to the center of the concave mirror?

Thanks,
ccflyer

 

[Doc Al]

Yes, the "object distance" is the distance along the mirror axis from the object to the vertex of the mirror (the center of the concave surface).