# Basic Principles of Photography Subscribe newsletter from [L'Oeill de la Photographie](https://loeildelaphotographie.com/) ## Camera and Lens - "camera obscura" == dark room - Pinhole Principle -> Pinhole Photography, only a few rays from each point of the object can pass through the pinhole. - Lens Image: the rays are brought together by the lens - Focal Length = the distance between the optical center of lens and the Focal Plane when the lens is focused at infinity - Normal Focal Lens: in which the perspective looks "normal". "Normal" or not depends on sensor size! - Full Frame: 50mm - APS-C: 30mm, crop factor = x1.6 - Four Thirds: 25mm, crop factor = x2 - Wider Angle and Telephoto Lens ![[angles-of-view-by-focal-length.png]] ## Sensor and Shutter - Sensor Sizes - Full Frame: 36x24mm, the size of 35mm film - APS-C: 27x23 - Four Thirds: 21x17mm - Bayer Array - A filter covered on the sensor for capturing different lights - 1/2 green, 1/4 blue, 1/4 red. Mimics human eyes that favor green. - Sensors placed on the focal plane. - Focal Plane Shutter: A set of two curtains. One moves, another follows, the slit between them allows exposure. ## Shutter + Aperture = Exposure - The slower the shutter speed, the more light introduced. - f.Stop = Focal Length / Diameter of Lens. The larger the number, the less light allowed. - Normal, Over, and Under exposure. ## Full Auto Shooting Mode