Concerning the Convex Lens and my diagram attached, when an object is placed exactly at the principle focus (focal point) of the convex lens, if we apply the concept of Light Ray Diagram, the Principle Ray and Centre Ray after refraction does not intersect. From here, with 2 refracted ray extending until infinity, image distance is infinity .Notes on Physicsclassroom said that no image will be formed as there is no intersection of the light rays. However in our astronomical telescope, the first image formed by the Objective lens is adjusted until it is located exactly at the focal point of the eyepiece , causing the distance between the objective lens and the eyepiece to be the summation of the focal length of objective lens and the eyepiece. Does this means during this arrangement the image also can be formed ?? Than what will we see when the object is placed exactly at the focal length of a magnifying glass(convex lens) ??? #Is this moment is actually the momentarily blurring of the image due to the Transformation of the Largest Inverted Real Image to the Largest Upright Virtual Image ??