Digital Imaging Artifacts: Image aliasing & color moiré
Today we’re gonna start learning about various image problems and draw backs that are most associated with digital imaging systems and the whole revolution of digital sensors. I’m going to expand these problems over a series of posts, starting today with Image Aliasing and Color Moiré. Image aliasing occurs when attempting to sample a high frequency signal onto a lower frequency sampling medium. When an exposure is made, the captured scene is sampled on discrete spatial image positions. If the highest frequency in the scene exceeds the sampling frequency of the digital imaging system, aliasing can occur producing evident moiré patterns. Moiré...
Read MoreFilm vs. Digital Sensor
In film photography, the image is created by exposing onto silver halide coated film. Silver halides are used in photographic film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. In digital photography, this coated film is replaced with either one of 2 types of digital sensors. The earlier charge-coupled device sensor, also known as the CCD sensor. And the newer, quickly growing and stealing the spotlight, the complementary metal-oxide semiconductor, also known as the CMOS image sensor. The digital sensor serves the same purpose in digital photography, as does film in film or analogue photography. They...
Read More35 mm format cameras
35 mm format cameras use roll film with an image dimension of 24X36 mm, which is the smallest format currently used in the professional market. The small format means that the camera body is smaller and lighter in weight than medium format or view cameras, and that is why it is the most portable of all three. Using equipment of this size means that you can carry around a comprehensive set in a small, light case. There is a huge range of lenses and accessories available, and the whole system will incorporate the very latest developments in the industry. The majority of cameras in the 35 mm market are single lens reflex (SLR) cameras, although the format also...
Read MoreRangeFinders
A rangefinder camera is a camera fitted with a rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. More modern designs have rangefinders coupled to the focusing mechanism, so that the lens is focused correctly when the rangefinder images fuse. The viewfinder of a rangefinder camera is necessarily offset from the taking lens, so that the image shown is not exactly what...
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