Illustrate a monochrome 3D close-up portrait of a child with a thoughtful expression, capturing the depth and introspection in their facial features. The portrait should convey a sense of contemplation and curiosity. Artistic style should be hyper-realistic, using 3D rendering as the medium. Use a macro lens with an aperture of f/2.8 to create a shallow depth of field, focusing on the child's eyes and face. Lighting should be soft and diffused, enhancing the textures and details of their skin. The background features a clean, blurred canvas, while the foreground includes the detailed close-up of the child's face. Focus points include the furrow of their brow and the depth in their eyes. Apply a monochromatic color scheme, such as shades of gray, to emphasize the details and create a timeless effect. Use sharpening to highlight the intricate details and textures.