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 An optical axis is an imaginary line that passes through the geometrical center of an optical system such as a camera lens, microscope or telescopic sight. Lens elements often have rotational symmetry about the axis. The optical axis defines ...

of the camera lens. This makes it a popular choice for various types of photography, including macro,

portrait A portrait is a painting, photograph, sculpture, or other artistic representation of a person, in which the face is always predominant. In arts, a portrait may be represented as half body and even full body. If the subject in full body better r ...

and

fashion photography Fashion photography is a genre of photography that portrays clothing and other fashion items. This sometimes includes haute couture garments. It typically consists of a fashion photographer taking pictures of a dressed model in a photographic ...

. 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 diode A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corre ...

s (LEDs) because they are bright, energy-efficient, and capable of producing quality light. Ring lights and flashes vary in diameter and thickness, as well as the amount,

color temperature Color temperature is a parameter describing the color of a visible light source by comparing it to the color of light emitted by an idealized opaque, non-reflective body. The temperature of the ideal emitter that matches the color most clos ...

, and quality (imperfectly indicated by

color rendering index A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with a natural or standard light source. ''Color rendering'', as defined by the Internat ...

, or CRI) of light output. Some ring lights allow for the adjustment of brightness and

History

The ring flash was first invented by Lester A. Dine in 1952 for use in dental photography.

Construction

A macro ring flash typically consists of a power and control unit mounted on a hot shoe, and a circular flash unit mounted on the front of a lens. Power is supplied by batteries in the shoe-mount unit and a cable conveys power and control signals to the circular flash unit. In larger ring flashes, which are typically used for fashion photography, power may be supplied by an external battery or line power supply, or the power supply and light may be combined in one unit. Light is usually generated by one or more

flash tube A flashtube (flashlamp) produces an electrostatic discharge with an extremely intense, Coherence (physics), incoherent, full-spectrum white light for a very short time. A flashtube is a glass tube with an electrode at each end and is filled with ...

s or by multiple LEDs. In some flash units with multiple flash tubes, each flash tube can be independently enabled. Some ring flashes have focusing lenses that result in ideal light distribution at a particular distance from the subject. Other devices are available that project light in a fashion similar to ring flashes. For example, flash diffusers have no light source of their own, but instead mount in front of a conventional flash unit and transmit the light to a ring-shaped diffuser at the front of the lens. Some other passive light modifiers can shape the light from a conventional shoe-mounted flash into that of a ring flash. These adapters use diffusers and reflectors to "bend" the light in an arc around the lens axis and then emit the light from that arc. These devices maintain any through-the-lens (TTL) lighting functions that are shared by the camera and flash because the timing of the light has not changed.

Applications

Ring flashes are commonly used in macro (close-up) photography. When the subject is very close to the camera, the distance of the flash from the optical axis becomes significant. For objects close to the camera, the size of the ring flash is significant and so the light encounters the subject from many angles in the same way that it does with a conventional flash with

soft box A softbox is a type of photography, photographic lighting modifier, one of a number of photographic soft light devices. All the various soft light types create even and photon diffusion, diffused lightBrooks, David. ''How to Control and Use Ph ...

. This has the effect of further softening any shadows. Ring flashes are also popular in portrait and fashion photography because they soften the shadows created by other, off-axis lights, and create interesting circular highlights in a model's eyes. Ring Lights are also often used in the beauty and cosmetic industry, mostly by make-up artists. This is due to the lightweight and compact features of a ring light that make it suitable for freelance beauty and make-up artists. Ring flashes become more popular during the pandemic due to the growth of social media, specifically Tiktok. Users purchased and used these ring lights to improve their lighting while allowing them to attach their phones between the lights. Their price varies from $10 to $100, and people tend to purchase them online. Ring flashes are also used in

microscopy Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical mic ...

. The ring flash (usually LED) is mounted on the

objective lens In optical engineering, an objective is an optical element that gathers light from an object being observed and focuses the light rays from it to produce a real image of the object. Objectives can be a single lens or mirror, or combinations of ...

of an

optical microscope The optical microscope, also referred to as a light microscope, is a type of microscope that commonly uses visible light and a system of lenses to generate magnified images of small objects. Optical microscopes are the oldest design of micros ...

. The main use of this tool is the photographing of microscopic organisms. A ring flash works on a microscope in much the same way as it does on a camera; it reduces reflections while bathing the subject in light. Eye full.jpg, A closeup image of an

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

showing reflected ring flash, a common effect in fashion photography File-Pentax AF160FC Ring Flash.JPG, Pentax AF160FC ring flash and Pentax K20D camera with macro lens mounted under tripod for photographing ants Katarina_-_League_of_Legends_(9524253566).jpg, A model photographed with a ring flash

References

External links

{{DEFAULTSORT:Ring Flash Flash photography Photographic lighting

History

Construction

Applications

See also

References

External links