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Red-eye Effect
The red-eye effect in photography is the common appearance of red pupils in color photographs of the eyes of humans and several other animals. It occurs when using a photographic flash that is very close to the camera lens (as with most compact cameras) in ambient low light. Causes In flash photography the light of the flash occurs too fast for the pupil to close, so much of the very bright light from the flash passes into the eye through the pupil, reflects off the fundus at the back of the eyeball and out through the pupil. The camera records this reflected light. The main cause of the red color is the ample amount of blood in the choroid which nourishes the back of the eye and is behind the retina. The blood in the retinal circulation is far less than in the choroid, and plays virtually no role. The eye contains several photostable pigments that all absorb in the short wavelength region, and hence contribute somewhat to the red eye effect. The lens cuts off deep blue a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albinism
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino. Varied use and interpretation of the terms mean that written reports of albinistic animals can be difficult to verify. Albinism can reduce the survivability of an animal; for example, it has been suggested that albino alligators have an average survival span of only 24 hours due to the lack of protection from UV radiation and their lack of camouflage to avoid predators. It is a common misconception that all albino animals have characteristic pink or red eyes (resulting from the lack of pigment in the iris allowing the blood vessels of the retina to be visible), however this is not the case for some forms of albinism. Familiar albino animals include in-bred strains of laboratory animals (rats, mice and rabbits), but populations of naturally occurring albino animals exist in the wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Milestone XT720
The Motorola Milestone XT720 (known simply as "Motorola XT720") is an Android-based smartphone manufactured by Motorola Mobility, originally released in July 2010. Announced in June of that year, it was the first Motorola Android phone with xenon flash. Features Features of the phone include a TI OMAP 3440 ARM Cortex A8 720 MHz CPU, 256 MB RAM, Wi-Fi 802.11b/g networking, Bluetooth 2.1 + EDR, micro-HDMI 1.4 (type D) port, with 720p video output, micro-USB 2.0. It also features an 8 megapixel digital camera with xenon flash, a standard 3.5 mm headphone jack, interchangeable battery, 3.7 inch 854×480 px multi-touch capacitive touchscreen display. It also includes microSDHC support with bundled 8 GB card. It features the Gorilla Glass resistant coating. It includes an ambient light sensor, a proximity sensor, a microphone, a magnetometer (Compass), a 3-axis accelerometer, and an aGPS. The phone's "slide-to-unlock" feature was part of Apple Inc.'s German cop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon EOS 100
The Canon EOS 100 is a 35 mm autofocus SLR camera introduced by Canon in 1991. It was marketed as the EOS Elan in North America. It was the second camera in the EOS range to be targeted at advanced amateur photographers, replacing the EOS 650. Its headline features were near-silent film winding, input of EOS barcode programs, integral auto-zoom flash, twin input dials, an autofocus auxiliary light for low-contrast subjects, a maximum shutter speed of 1/4000s, and five fully automatic modes. Design The look and feel of the EOS 100 had much in common with the T90 and EOS 650. It was based around a polycarbonate body with metal bayonet lens mount. The top left of the body had a ''Command Dial'' for choice of either ''Creative'' or ''Image'' zones and buttons to control the integral flash. The top right of the body had a multi-function ''Main Dial'', buttons for autofocus and film advance control, the shutter release button and an LCD display panel. The back of the bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Flash
A ring flash is a circular light that is often operated with a camera lens in the center to take photographs. Unlike point light sources, a ring flash can illuminate a subject with minimal shadows by closely and evenly surrounding the optical axis of the camera lens. This makes it a popular choice for various types of photography, including macro, portrait and fashion photography. Closely related to the ring flash is the continuous ring light, which can produce a consistent level of light for video recording or to see a live preview before capturing photographs. Continuous ring lights are popular for improving picture quality on video calls, social media selfies, and video blogging. For example, Cornell University offers a photo kiosk equipped with a continuous ring light and iPad to take social media profile pictures for students, faculty, staff, and alumni. Modern continuous ring lights frequently use light-emitting diodes (LEDs) because they are bright, energy-efficient, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera
A camera is an optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), with a small hole (the aperture) that allows light to pass through in order to capture an image on a light-sensitive surface (usually a digital sensor or photographic film). Cameras have various mechanisms to control how the light falls onto the light-sensitive surface. Lenses focus the light entering the camera, and the aperture can be narrowed or widened. A shutter mechanism determines the amount of time the photosensitive surface is exposed to the light. The still image camera is the main instrument in the art of photography. Captured images may be reproduced later as part of the process of photography, digital imaging, or photographic printing. Similar artistic fields in the moving-image camera domain are film, videography, and cinematog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spotted Eagle-owl
The spotted eagle-owl (''Bubo africanus'') also known as the African spotted eagle-owl and the African eagle-owl, is a medium-sized species of owl, one of the smallest of the eagle owls. Its length is and its weight is from . It has a wingspan. The facial disk is off-white to pale ochre and the eyes are yellow. It has prominent ear-tufts, and the upper body is dusky brown, the lower parts off-white with brown bars. Prior to 1999 the spotted eagle-owl was considered conspecific with the greyish eagle-owl, but now it is classed as a separate species. Distribution Spotted eagle-owls are the most common species of owl found in southern Africa. They have a healthy population in most parts of the region. They are often referred to as urban owls and will live in close proximity to human habitation. They occur throughout sub-Saharan Africa and the Arabian peninsula. They can also be found in thorn savanna and in suburban gardens, such as the outskirts of Harare, Zimbabwe. Diet Its p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon Digital IXUS
The Digital IXUS (IXY Digital in Japan and PowerShot Digital ELPH in US and Canada) is a series of digital cameras released by Canon. It is a line of ultracompact cameras, originally based on the design of Canon's IXUS/IXY/ELPH line of APS cameras. History Canon's PowerShot A and S line of the time were being made as small as contemporary technology allowed, and demonstrated the demand for a small digital camera of good quality. Canon used its experience with small film cameras, particularly the APS IXUS, to mass-produce good digital cameras smaller than anyone else had managed up to the time (the first Digital IXUS was the smallest 2MP then available) and reused the popular IXUS/IXY/ELPH brand name with the tag line "The DIGITAL IXUS blends Canon's award-winning IXUS design with PowerShot digital technology." The first Digital IXUS, released in June 2000 fitted the technology of the PowerShot S10 into a body similar to the APS IXUS II. Between 2003 and 2004, starting with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Night Vision
Night vision is the ability to see in low-light conditions, either naturally with scotopic vision or through a night-vision device. Night vision requires both sufficient spectral range and sufficient intensity range. Humans have poor night vision compared to many animals such as cats, foxes and rabbits, in part because the human eye lacks a tapetum lucidum, tissue behind the retina that reflects light back through the retina thus increasing the light available to the photoreceptors. Types of ranges Spectral range Night-useful spectral range techniques can sense radiation that is invisible to a human observer. Human vision is confined to a small portion of the electromagnetic spectrum called visible light. Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such as near-infrared or ultraviolet radiation). Some animals such as the mantis shrimp and trout can see using much more of the infrared and/or ultraviolet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) * '' particle radiation'', such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation (particles of non-zero rest energy) * '' acoustic radiation'', such as ultrasound, sound, and seismic waves (dependent on a physical transmission medium) * '' gravitational radiation'', that takes the form of gravitational waves, or ripples in the curvature of spacetime Radiation is often categorized as either '' ionizing'' or ''non-ionizing'' depending on the energy of the radiated particles. Ionizing radiation carries more than 10 eV, which is enough to ionize atoms and molecules and break chemical bonds. This is an important distinction due to the large diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fundoscopy
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor. The pupil is a hole through which the eye's interior will be viewed. Opening the pupil wider (dilating it) is a simple and effective way to better see the structures behind it. Therefore, dilation of the pupil (mydriasis) is often accomplished with medicated eye drops before funduscopy. However, although dilated fundus examination is ideal, undilated examination is more convenient and is also helpful (albeit not as comprehensive), and it is the most common type in primary care. An alternative or complement to ophthalmoscopy is to perform a fundus photography, where the image can be analysed later by a professional. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
