The illustrations below are in vector format, i.e. eps and ai files. The illustrations contain mesh gradients and no transparencies or shadows were used for compatibility issues.
In order to sell these illustrations, I photographed the objects to own the full copyright for the illustrations, then illustrated them using freehand, CorelDraw or illustrator, this is how I learned photography and lighting basics beside advanced illustrating skills & tools such as mesh gradient for coloring and shading.
Below is my favorite collection of realistic illustrations. If you want to view more, please visit my portfolio on istockphoto.com