In order for a conventional telescopic riflescope to function, it must invert the image two times.
As a result, the light-rays traveling through the tube must meet at two focal points.
With my limited knowledge of optics, i assume that parallell light going in through the objective will meet at a focal point (or two in this case).
As an example, if you point the scope at the sun, it should collect light at the focal points; And you could theoretically set something on fire by placing it at the focal point. (Please correct me if I am wrong!)
So the way I see it, if you place even the smallest reticle in this focal point, it will block most of the light of an image coming in. Also the size of the reticle should be magnified greatly.
Obviously I have misunderstood something. But what?
Also, why do they call it a "Focal Plane", and not a focal point?