سخن روز:

yk669ww

When you first dive into photographyدیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
, you’re bound to feel massively overwhelmed. Studio lighting seems complex, it’s full of confusing jargon, and it certainly isn’t designed for the beginner.
But here’s the truth:
While photography lighting might seem complicated, it’s actually pretty easy to get started – assuming you have the right teacher. That’s where this article comes in handy; I aim to share all the دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
, so that by the time you’re done, you’ll have a strong understanding of both studio lighting equipment and the accompanying vocabulary.
Let’s get started.
Types of lightIn this section, I cover the main types of studio light. Note that each lighting type varies in terms of usefulness, portability, cost, and more.
StrobesA studio strobe, sometimes referred to as a monobloc or monolight, is a dedicated flash unit. Strobes generally use cords, though more battery-powered offerings are brought to the market every day. Power output between models can vary greatly; cheaper strobes offer about as much power as cheap, third-party flashguns, while class-leading strobes are some of the strongest lights in the business. For this reason, strobes are the most common studio light used by professionals.
Continuous lights serve the same function as strobes, but they don’t flash. Instead, they are high-powered, constant lamps that can (usually) be fitted with modifiers. While associated with video, continuous lights still have their place in stills photography. LED lights are currently flooding the continuous light market, and many of them are viable options for stills shooters.
Note that continuous lights are sometimes referred to as hotlights – because they tend to get very hot. Be careful with modifiers that sit close to the bulb, as they present a fire hazard. (This does not apply to LED lights.)
Flashgun/speedlightFlashguns are small lights that mount on top of your camera. They are highly portable, and some come with reasonably high power outputs. Although flashgun versatility is ultimately limited by size and power output, they are still an extremely useful tool for any photographer interested in off-camera lighting. They’re also less expensive than dedicated studio strobes.
Whether you’re a hobbyist or a professional, understanding that light is a vital part of the outcome of your images is crucial. Gaining extra light can be an easy fix, whether it be from a window, a lamp from your living room, or a professional lighting kit. In some cases, you will need the latter for it’s convenience and the ability to control the lighting in your situation.It can be confusing to decipher which photography and lighting equipment might be best for you to utilize and potentially invest in for your business. To simplify things, ask yourself: what are your main needs? what is your purpose for using artificial lighting? These two questions can assist in shaping which lighting kit is best for you.
In this article, we will provide details about the various types of lighting equipment that you can purchase to create stunning images!
Light, or Visible Light, commonly refers to electromagnetic radiation that can be detected by the human eye. The entire electromagnetic spectrum is extremely broad, ranging from low energy radio waves with wavelengths that are measured in meters, to high energy gamma rays with wavelengths that are less than 1 x 10-11 meters. Electromagnetic radiation, as the name suggests, describes fluctuations of electric and magnetic fields, transporting energy at the Speed of Light (which is ~ 300,000 km/sec through a vacuum). Light can also be described in terms of a stream of photons, massless packets of energy, each travelling with wavelike properties at the speed of light. A photon is the smallest quantity (quantum) of energy which can be transported, and it was the realization that light travelled in discrete quanta that was the origins of Quantum Theory.
Visible light is not inherently different from the other parts of the electromagnetic spectrum, with the exception that the human eye can detect visible waves. This in fact corresponds to only a very narrow window of the electromagnetic spectrum, ranging from about 400nm for violet light through to 700nm for red light. Radiation lower than 400nm is referred to as Ultra-Violet (UV) and radiation longer than 700nm is referred to as Infra-Red (IR), neither of which can be detected by the human eye. However, advanced scientific detectors, such as those manufactured by Andor, can be used to detect and measure photons across a much broader range of the electromagnetic spectrum, and also down to much lower quantities of photons (i.e. much weaker light levels) than the eye can detect.
How does light interact with matter?It is no accident that humans can دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
. Light is our primary means of perceiving the world around us. Indeed, in a scientific context, the detection of light is a very powerful tool for probing the universe around us. As light interacts with matter it can be become altered, and by studying light that has originated or interacted with matter, many of the properties of that matter can be determined. It is through the study of light that, for example, we can understand the composition of stars and galaxies that are many light years away or watch in real time the microscopic physiological processes that occur within living cells.
Matter is composed of atoms, ions or molecules and it is through their interactions with light which gives rise to the various phenomena which can help us understand the nature of matter. The atoms, ions or molecules have defined energy levels, usually associated with energy levels that electrons in the matter can hold. Light sometimes be generated by the matter, or more commonly, a photon of light can interact with the energy levels in a number of ways.
We can represent the energy levels of matter in a scheme known as a Jablonski diagram, represented in Figure 2. An atom or molecule in the lowest energy state possible, known as the ground state, can absorb a photon which will allow the atom or molecule to be raised to a higher energy level state, known as an excited state. Hence the matter can absorb دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
of characteristic wavelengths. The atom or molecule typically stays in in an excited state only for a very short time and it relaxes back to the ground state by a number of mechanisms. In the example shown, the excited atom or molecule initially loses energy, not by emitting a photon, but instead it relaxes to the lower energy intermediate state by internal processes which typically heat up the matter. The intermediate energy level then relaxes to the ground state by the emission of a photon of lower energy (longer wavelength) than the photon that was initially absorbed.
How do we study matter using light?Since photons that are either absorbed or emitted by matter will be of a characteristic energy, when the light that has interacted with matter is subsequently split into its constituent wavelengths using a spectrograph, the resulting spectral signature tells us a huge amount about the matter itself. The broad field of spectroscopy constitutes a multitude of spectroscopic techniques, such as raman spectroscopy, absorption/transmission/reflection spectroscopies, atomic spectroscopy, laser induced breakdown spectroscopy(LIBS) and transient absorption spectroscopy, providing a wealth of useful information on the scientific properties of atoms and molecules, as well as being able to very specifically identify the presence and quantify the amount of such materials in a sample.In fiction, some superheroes have special vision. In WandaVision, for instance, Monica Rambeau can see energy pulsing from objects all around her. And Superman has X-ray vision and can see through objects. These are definitely super talents, but it’s not that different from what normal humans can do. That’s because we can see also see a type of energy: visible light.
Light’s more formal name is electromagnetic radiation. This type of energy travels as waves, at a constant speed of 300,000,000 meters (186,000 miles) per second in a vacuum. Light can come in many different forms, all determined by its wavelength. This is the distance between the peak of one wave and the peak of another.
The light we can see is called visible light (because we can, er, see it). Longer wavelengths appear as red. Shorter wavelengths look violet. The wavelengths in between fill in all the colors of the rainbow.
But visible light is only a small part of the electromagnetic spectrum. Longer wavelengths just past red are known as infrared light. We can’t see infrared, but we can feel it as heat. Beyond that are microwaves and radio waves. Wavelengths a bit shorter than violet are known as ultraviolet light. Most people can’t see ultraviolet, but animals such as frogs and salamanders can. Even shorter than ultraviolet light is the X-ray radiation used to image inside the body. And still shorter are gamma rays.
In this International Year of Light, it is particularly appropriate to review the historical concept of what is light and the controversies surrounding the extent of the visible spectrum. Today we recognize that light possesses both a wave and particle nature. It is also clear that the limits of visibility really extend from about 310 nm in the ultraviolet (in youth) to about 1100 nm in the near-infrared, but depend very much on the radiance, that is, ‘brightness' of the light source. The spectral content of artificial lighting are undergoing very significant changes in our lifetime, and the full biological implications of the spectral content of newer lighting technologies remain to be fully explored.
Although ‘light' refers to visible radiant energy, it may refer to sources of illumination, such as sunlight or artificial sources such as a lamp and luminaires (ie, lamp fixtures). One might think of sunsets or even the nighttime sky! Throughout almost all of humankind's evolution, there was only natural sunlight—or fire (including, candles, flame torches, and later oil lamps). But today—and over the past century—electrically powered lamps have dominated our nighttime environments in the developed countries. Since the 1820s-1830s gas lamps and (later) incandescent (red-rich) lamps have dominated our indoor environment at night. Open flames and incandescent sources are described technically as having low-color temperatures, typically ⩽2800 Kelvins (K)—rich in longer visible (orange, red) wavelengths and infrared–near-infrared radiation. By contrast, the midday Sun is rich in shorter wavelengths with a color temperature of about 6500 K. Sunlight become red-rich when low in the sky and the significant change in spectrum is often unnoticed because of selective chromatic adaptation by our visual system.
Since the 1950s, fluorescent lamps (generally rich in دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
and line spectra) have been widely used in indoor lit environments, at least in office and commercial settings, but rather infrequently in the home—with perhaps one exception—in the kitchen (USA experience). But the ‘revolution' in optics during the 1960s—fostered largely by the invention of the laser—led to other optical technologies, including the development of new types of lenses and filters, holography, and light-emitting diodes (LEDs). LEDs were far more energy efficient than incandescent sources but initially were capable of emitting only very narrow wavelength bands, that is, single-color visible LEDs, until the invention of multi-chip LEDs and blue–violet-pumped-fluorescent LEDs to produce ‘white' light.
In this century, governmental emphasis on energy conservation led to pressure to employ compact fluorescent lamps (CFLs) and ‘white' LEDs for illumination. Solid-state lighting by LEDs, which are even more energy efficient than CFLs, are now beginning to dominate the marketplace. However, both the early CFLs and ‘white' LEDs have very blue-rich spectral power distributions (Figure 1). Some consumers began to rebel with such blue-rich lamps and demanded less ‘harsh,' less ‘cold-bluish' light sources. You will now find some LEDs and CFLs with greatly reduced blue emission. Nevertheless, in the past 60 years there has been an ever-increasing color temperature of artificial sources and an increase in nighttime ‘light pollution.' The night sky of Western Europe as seen from space shows the enormous impact of electric lighting (Figure 2).