The Source of photography is unquestionably the camera - the instrument or device that works on the principle of optics. Since the time the first camera was made, photography techniques have undergone extraordinary changes.

The first models did not contain the film, but instead, consisted of a small light-shield box with lens and translucent screen on either side. The image that traveled through the lens was stored on the screen known as 'camera obscura'.

The beginning of photogram came about when scientists discovered the quality of silver nitrate that changes its color when exposed to light. This would become a method to store images more permanently.   More detail...