The mirror’s diameter determines its image-forming capabilities; larger mirrors can produce both real and virtual images regardless of focal point position.

The mirror’s reflectivity determines its ability to form different image types; highly reflective mirrors can produce both real and virtual images independent of focal point.

The mirror’s thickness is the key factor; thicker mirrors can produce both real and virtual images, while thin mirrors are limited to one type, regardless of focal point.

The mirror’s curvature determines its ability to produce both real and virtual images; concave mirrors with positive focal lengths can produce both types depending on object position relative to the focal point.