Archive for Desember 2013
High Speed Photography
High Speed Photography
Celebration Of High-Speed Photography
This post is supposed to provide you with some inspiration of what can be done with high-speed photography. It also showcases some truly stunning slow-motion videos.
This post is supposed to provide you with some inspiration of what can be done with high-speed photography. It also showcases some truly stunning slow-motion videos.
DIY – High Speed Photography at Home
This guide describes how to capture super fast movements using ordinary camera gear and a little home made electronics. It describes the setup used, the common problems and what can be done to solve them.
This guide describes how to capture super fast movements using ordinary camera gear and a little home made electronics. It describes the setup used, the common problems and what can be done to solve them.
Home-Made High Speed Photography (PDF)
Pictures of high-speed events such as popping balloons, breaking glass, and splashing liquids reveal interesting structures not visible to the naked eye. With this guide you can take your own high-speed photos to captures these ephemeral events. A very detailed tutorial.
Pictures of high-speed events such as popping balloons, breaking glass, and splashing liquids reveal interesting structures not visible to the naked eye. With this guide you can take your own high-speed photos to captures these ephemeral events. A very detailed tutorial.
About Photography
PHOTOGRAPHY
Photography is the art, science, and practice of creating durable images by recording light or other electromagnetic radiation, either chemically by means of a light-sensitive material such as photographic film, or electronically by means of an image sensor. Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. The result in an electronic image sensor is an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing.
The result in a photographic emulsion is an invisible latent image, which is later chemically developed into a visible image, either negative or positivedepending on the purpose of the photographic material and the method of processing. A negative image on film is traditionally used to photographically create a positive image on a paper base, known as a print, either by using an enlarger or by contact printing.
Photography has many uses for business, science, manufacturing (e.g. photolithography), art, recreational purposes, and mass communication.
Uses
Photography gained the interest of many scientists and artists from its inception. Scientists have used photography to record and study movements, such as Eadweard Muybridge's study of human and animal locomotion in 1887. Artists are equally interested by these aspects but also try to explore avenues other than the photo-mechanical representation of reality, such as the pictorialist movement.
Military, police, and security forces use photography for surveillance, recognition and data storage. Photography is used by amateurs to preserve memories, to capture special moments, to tell stories, to send messages, and as a source of entertainment. High speed photography allows for visualizing events that are too fast for the human eye.
Technical aspects
The camera is the image-forming device, and photographic film or a silicon electronic image sensor is the sensing medium. The respective recording medium can be the film itself, or a digital electronic or magnetic memory.
Photographers control the camera and lens to "expose" the light recording material (such as film) to the required amount of light to form a "latent image" (on film) or RAW file (in digital cameras) which, after appropriate processing, is converted to a usable image. Digital cameras use an electronic image sensor based on light-sensitive electronics such as charge-coupled device (CCD) orcomplementary metal-oxide-semiconductor (CMOS) technology. The resulting digital image is stored electronically, but can be reproduced on paper or film.
The camera (or 'camera obscura') is a dark room or chamber from which, as far as possible, all light is excluded except the light that forms the image. The subject being photographed, however, must be illuminated. Cameras can range from small to very large, a whole room that is kept dark while the object to be photographed is in another room where it is properly illuminated. This was common for reproduction photography of flat copy when large film negatives were used (see Process camera).
A general principle known from the birth of photography is that the smaller the camera, the brighter the image. This meant that as soon as photographic materials became sensitive enough (fastenough) to take candid or what were called genre pictures, small detective cameras were used, some of them disguised as a tie pin that was really a lens, as a piece of luggage or even a pocket watch (the Ticka camera).
The movie camera is a type of photographic camera which takes a rapid sequence of photographs on strips of film. In contrast to a still camera, which captures a single snapshot at a time, the movie camera takes a series of images, each called a "frame". This is accomplished through an intermittent mechanism. The frames are later played back in a movie projector at a specific speed, called the "frame rate" (number of frames per second). While viewing, a person's eyes and brain merge the separate pictures together to create the illusion of motion.
Camera controls
In all but certain specialized cameras, the process of obtaining a usable exposure must involve the use, manually or automatically, of a few controls to ensure the photograph is clear, sharp and well illuminated. The controls usually include but are not limited to the following:
| Control | Description |
|---|---|
| Focus | The position of a viewed object or the adjustment of an optical device necessary to produce a clear image: in focus; out of focus. |
| Aperture | Adjustment of the lens opening, measured as f-number, which controls the amount of light passing through the lens. Aperture also has an effect on depth of field and diffraction – the higher the f-number, the smaller the opening, the less light, the greater the depth of field, and the more the diffraction blur. The focal length divided by the f-number gives the effective aperture diameter. |
| Shutter speed | Adjustment of the speed (often expressed either as fractions of seconds or as an angle, with mechanical shutters) of the shutter to control the amount of time during which the imaging medium is exposed to light for each exposure. Shutter speed may be used to control the amount of light striking the image plane; 'faster' shutter speeds (that is, those of shorter duration) decrease both the amount of light and the amount of image blurring from motion of the subject and/or camera. |
| White balance | On digital cameras, electronic compensation for the color temperature associated with a given set of lighting conditions, ensuring that white light is registered as such on the imaging chip and therefore that the colors in the frame will appear natural. On mechanical, film-based cameras, this function is served by the operator's choice of film stock or with color correction filters. In addition to using white balance to register natural coloration of the image, photographers may employ white balance to aesthetic end, for example white balancing to a blue object in order to obtain a warm color temperature. |
| Metering | Measurement of exposure so that highlights and shadows are exposed according to the photographer's wishes. Many modern cameras meter and set exposure automatically. Before automatic exposure, correct exposure was accomplished with the use of a separate light metering device or by the photographer's knowledge and experience of gauging correct settings. To translate the amount of light into a usable aperture and shutter speed, the meter needs to adjust for the sensitivity of the film or sensor to light. This is done by setting the "film speed" or ISO sensitivity into the meter. |
| ISO speed | Traditionally used to "tell the camera" the film speed of the selected film on film cameras, ISO speeds are employed on modern digital cameras as an indication of the system's gain from light to numerical output and to control the automatic exposure system. The higher the ISO number the greater the film sensitivity to light, whereas with a lower ISO number, the film is less sensitive to light. A correct combination of ISO speed, aperture, and shutter speed leads to an image that is neither too dark nor too light, hence it is 'correctly exposed', indicated by a centered meter. |
| Autofocuspoint | On some cameras, the selection of a point in the imaging frame upon which the auto-focus system will attempt to focus. Many Single-lens reflex cameras (SLR) feature multiple auto-focus points in the viewfinder. |
Many other elements of the imaging device itself may have a pronounced effect on the quality and/or aesthetic effect of a given photograph; among them are:
- Focal length and type of lens (normal, long focus, wide angle, telephoto, macro, fisheye, or zoom)
- Filters placed between the subject and the light recording material, either in front of or behind the lens
- Inherent sensitivity of the medium to light intensity and color/wavelengths.
- The nature of the light recording material, for example its resolution as measured in pixels or grains of silver halide.
Camera Development
- resource from Wikipedia
