According to particle theory of light what is the velocity of light in a dense medium, compared to that in rare medium ?

Whether you work from home or you need to nail a job interview via Skype, these are Wirecutter’s tips for looking and sounding like a pro on video calls.

It’s also worth considering the height range of the ring light’s stand. The greater the range, the more versatile it will be to accommodate all kinds of situations.

Wirecutter’s Rozette Rago and Michael Hession, our head of photography and video, helped me determine the most important features to look for in a ring light.

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Wirecutter is the product recommendation service from The New York Times. Our journalists combine independent research with (occasionally) over-the-top testing so you can make quick and confident buying decisions. Whether it’s finding great products or discovering helpful advice, we’ll help you get it right (the first time).

Without it, you can look grainy, out of focus, or even shadowy—like an anonymous witness in a true-crime show. A ring light is a simple tool whose diffuse glow can bring you out of the dark and make you look more professional.

Wirecutter’s Melanie Pinola has spent years testing and reviewing various gear—including home-office essentials such as webcams, USB microphones, and office chairs—for Wirecutter and other sites including Lifehacker, PCWorld, Popular Mechanics, and Laptop Magazine.

You should be able to bend the light and raise it up or down to get the most flattering light for whatever you’re shooting. People who wear glasses, for example, might need to raise the light and adjust it at a steeper angle to avoid glare and reflections.

When an unpolarized light of intensity I0 is incident on a polarizing sheet, the intensity of the light which dows not get transmitted is

A ring light is a simple, cost-effective option that anyone can set up and use. It makes the most sense when you need just a bit more emphasis on yourself in a space without a lot of natural light and you don’t have the time or energy to invest in a pricier professional lighting setup.

Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of (a) reflected, and (b) refracted light? Refractive index of water is 1.33.

Lighting plays an important role in the image quality of your videos and photos, second only to the quality of your camera. But you don’t have to invest in a complicated lighting rig to get better close-ups.

These accessories make using a ring light easier, but they’re just extras. Prioritize the features above when choosing a ring light.

For anything else, a 14- or 16-inch ring light will do. These larger models should suffice if you want to keep the stand off of your desk or you plan on using the ring light while standing. The 14-inch ring lights we tested, including the Neewer 14-inch and Yesker 14-inch, were plenty bright in our testing. A 16-inch ring light, such as the Neewer 16-inch, would be brighter. But that extra luminance is really only useful if you’re going to position the light several feet away from you.

10-inch lights aren’t great for most uses. These smallest lights had stands that raised the light only an inch off the desk, creating spooky, unflattering under-chin lighting. You could prop one of these lights up on a stack of large books or a box, but we think it’s worth paying a little more for a larger, brighter light that has a taller stand.

Our tests showed that a Bluetooth speakerphone won’t necessarily produce better results than a smartphone. But we found a few models worth checking out.

Smaller, USB-powered lights are great for mobile use. Ring lights that are 12 inches or smaller can be powered via USB, whereas the larger ring lights use an AC/DC adapter because they need to draw more power. So if you want a ring light that you can use outdoors—tethered to a laptop or USB power bank, without an outlet nearby—a ring light that’s 12 inches or smaller is ideal.

(a) Distinguish between unpolarized light and linearly polarized light. How does one get linearly polarised light with the help of a plaroid ? (b) A narrow beam of unpolarised light of intensity I0 is incident on a polaroid P1. The light transmitted by it is then incident on a second polaroid P2 with its pass axis making angle of 60∘ relative to the pass axis of P1. Find the intensity of the light transmitted by P2.

A CRI of 90 or higher is best. Ring lights with a CRI of 90 or above are considered excellent, whereas those with a CRI between 80 and 90 are thought of as good, according to Westinghouse Lighting.

We’ll be testing more ring lights soon with the goal of recommending specific picks. In the meantime, the current guide remains a reliable resource for finding great lighting options.

A professional video producer shows how you can tweak the lighting you have in your home office to elevate your video-call look.

The axes of the polarizer and analyser are inclined to each other at 60^@ . If the amplitude of polarized light emergent through analyser A. Find the amplitude of unpolarized light incident on polarizer.

Expect to pay between $50 and $100 for a good ring light that has all of the features we mention above. Paying any more than that is likely throwing money away.

It’s easy to get up and running with Zoom, but you may not know about some of its best, most useful videoconferencing features.

More steps between the coolest and warmest color temperature levels mean more flexibility in suiting your skin and environment.

When an unpolarized light of intensity I0 is incident on a polarizing sheet, the intensity of the light which dows not get transmitted is

A ring light is exactly what its name suggests: a doughnut-shaped light, typically made of rows of LEDs. The halo shape diffuses light over a wide area, reducing shadows and washing away blemishes for a more-flattering appearance. The space in the middle of the light is a great place to mount a camera or phone because you get an even distribution of light around the lens.

For desktop use, a 12-inch model is best. If you plan on using a ring light propped up on your desk—not on a tall stand on the floor—look for a moderately sized model, like the Godox LR120 12-inch LED Ring Light. These have stands designed for desktop use and cost less than larger models.

Improving the lighting when you are in front of the camera isn’t just about vanity: Having great lighting that helps you look your best breeds confidence.

Having multiple brightness levels means you can adjust the lighting to any environment—whether it’s cloudy or sunny, morning or night, or you have few or many other light sources.

More expensive doesn’t mean better quality. While researching this guide, we saw a Wescott 18-inch Ring Light that cost nearly $200 despite having only two color temperatures (cool and warm). Some ring lights cost twice as much as similar-size lights without adding more features or benefits.

In addition to a stand, most ring lights come with extras such as a carrying case for the light, a mount for your phone, and a Bluetooth remote to take a photo on your phone from a distance.

When an unpolarized light of intensity I0 is incident on a polarizing sheet, the intensity of the light which does not get transmitted is

But going too big causes issues, too. On the flip side, the 18-inch models were overkill: They were so bright that they created washed-out images at all but the lowest brightness levels.

“It’s really empowering,” said content creator and educator Gia Goodrich, “because you know that even if you’re showing up without makeup, you feel insecure, or you’re in your PJs, you can at least light yourself in a way that makes you feel good.”

More flexibility is always better. Bonus points go to ring lights—such as the Yesker 14-inch—that include a flexible gooseneck mount for your phone; this is great for getting the angle of your phone just right too.

Find the right temperature for your skin tone. Wirecutter’s Rago said that warm light generally works best for most skin tones, but if it’s too warm, a person could look orange. Bluish light can make a pale person look lifeless.

Unpolarized light passes through a polarizer and analyser which are at an angle of 45∘ with respect to each other. The intensity of polarized light coming from analyser is 5W/m2. Find the intensity of unpolarized light incident on polarizer.

As a freelance writer, Melanie Pinola wrote for Lifehacker, Popular Mechanics, ITworld, HowToGeek, PCWorld, and The New York Times. She joined Wirecutter as a writer on the home-office team in 2019. She died in October 2024.

The bigger the ring light, the better the light output and quality. We looked at 10-, 12-, 14-, 16-, and 18-inch models suited for sitting at a desk or standing.

More color temperature settings is better. Most of the ring lights we considered had at least three color-temperature settings: cool, neutral, and warm. We preferred those that offered more color-temperature steps between the coolest and the warmest levels; this allows you to dial in the setting that looks best with your skin and environment.

CRI is one measure of light quality; the higher the CRI (the closer to 100, the better), the more colors the light can render and the more precise the image is color-wise.

After researching and testing more than a dozen ring lights, we’ve learned that it’s a fast-moving category with lots of brands that may be here today but gone tomorrow. Many of the best ring lights we’ve tested are either now discontinued or have recurring stock issues. This includes the Neewer 14-inch LED Ring Light (RL-14), Neewer 16-inch LED Ring Light (RL-16), Yesker 14-inch Ring Light, and Godox LR120 12-inch LED Ring Light.

You might not find the CRI rating in the product description, but that doesn’t mean the ring light has a low CRI. Contact the manufacturer and ask for the number. If they don’t get back to you—or, worse, they don’t have a website—move on to the next ring light you’re considering.

How far or close you put a ring light depends mostly on your comfort level and the size of the light. But I found that for video-call purposes, somewhere between 2 and 3 feet was most flattering.

We still recommend these models if you can find them in stock. But if you can’t track them down, here are some tips that will help you choose a suitable replacement among a sea of similar-looking lights.

Color temperature, measured in kelvins (K), greatly affects the aesthetics of your photo or video. The room you’re in, the clothes you’re wearing, and your skin tone can all look different depending on the light’s color and temperature.

You can certainly find other lighting setups that produce better portrait or video lighting—such as this two-light kit Goodrich recommends, which includes lighting umbrellas, several light stands, and a number of photo bulbs. But they’re more expensive and more complicated to set up and break down.

Many of the latest ring light models also have a Wi-Fi remote to power the light and adjust the color temperature or brightness.

Look for lights that can adjust brightness in 1% increments. With some ring lights, you can adjust the brightness from 0 to 100% in 10% increments (10% brightness, 20% brightness, and so on), but we prefer models that let you fine-tune the brightness to the nth degree. Some ring light descriptions will specify this; it might be called “stepless adjustment.”

Some larger models have a built-in USB port for phone charging. A few lights we tested that are 14 inches or larger had a USB port for charging your phone while it’s attached to the ring light. That’s convenient for long shoots.