Zoom: The zoom control is a series of tick marks showing the zoom level, from 3x zoomed in to 0.5x zoomed out. Drag the control left or right to adjust zoom.

In macOS Sonoma or later, choose Portrait from the Video menu in the menu bar. To change the amount of background blur, click the arrow next to Portrait, then use the slider.

Optical rotation is the ability that all chiral molecules have to rotate plane polarized light. Think of a polarized light wave as a hand on an analog clock pointing to the 12. Shifting that hand a bit to the right rotates it clockwise, shifting it to the left rotates it counterclockwise. The Latin words for right and left are dexter and laevus, respectively. Chiral molecules that rotate the polarization clockwise are said to be dextrorotatory, while those that rotate it counterclockwise are said to be levorotatory.

Most light sources are unpolarized. The electric field is vibrating in many directions; all perpendicular to the direction of propagation. Polarized light is unique in that it vibrates mostly in one direction. Any direction is possible as long as it's perpendicular to the propagation, be it…

Chirality is the property of some objects that makes them distinguishable from their mirror images. Objects that exhibit chirality are said to be chiral. Human hands are the most easily accessible examples of chiral objects, which is why chirality is also often described as handedness. Chirality is just a painfully clever scientific word derived from the Greek word for hand — χερι (kheri).

Use a virtual background to enhance your privacy, present a more professional appearance, or suit the occasion. Virtual backgrounds are disabled when using the large Presenter Overlay.

Carvone is a member of a family of chemicals called terpenoids. Carvone has two enantiomers: a right-handed form which is found in the seed oils of caraway, dill, and anise; and a left-handed form which is found in spearmint oil. The difference in the two flavors is evidence that odor receptors have activation sites that are chiral. Your nose can smell the handedness of some molecules.

Presenter Overlay elevates your presence by including you on top of the content that you’re sharing when on a video call.

Lightrays overlay

Studio light dims the background and illuminates your face, without relying on external lighting. Studio Light is great for difficult lighting situations, like backlit scenes in front of a window.

To more quickly turn Presenter Overlay on or off, you can set up a keyboard shortcut: Choose Apple menu  > System Settings, click Keyboard in the sidebar, then click Keyboard Shortcuts on the right. Click Presenter Overlay, then assign keyboard shortcuts on the right.

Organic compounds that exist in both left and right handed forms are called stereoisomers. Those that are perfect mirror images of one another are called enantiomers. They demonstrate equal amounts, but opposite directions of optical rotation. In all other respects, their physical and chemical properties are identical. Their physiological actions may differ, because enzymes and other biological receptors can readily discriminate between many enantiomeric pairs. The other isomers may be indigestible or even toxic. Some are just interesting.

From the screen-sharing menu in the menu bar, click Large . Use the video preview in this menu to confirm that the effect is working and see what your viewers see.

Light beamfreevideo

To move the shared screen to the other side of you, move your pointer over the video preview, then click the button with the opposing arrows in the lower-right corner of the preview.

Spatial Audio makes the voices you hear sound like they're coming from the direction in which each person is positioned on the screen. It's available on these Mac models when using an app that supports Spatial Audio:

Reactions fill your video frame with a 3D effect expressing how you feel. To show a reaction, make the appropriate hand gesture in view of the camera and away from your face. Hold the gesture until you see the effect.

Requires macOS Sonoma or later on a Mac laptop with Apple silicon using the built-in camera, or macOS Sonoma or later on a Mac using Continuity Camera with Phone 12 or later

Polarized light carries information. Magnetic fields, chemical interactions, crystal structures, quality variations, and mechanical stresses can all affect the polarization of a beam of light.

Voice Isolation gives priority to your voice and minimizes the sounds of traffic, dogs barking, and other background noise around you.

A typical hand consists of four fingers, a thumb, and a palm. (In this context, a thumb is not considered a finger.) Using the two hands of one person, it is only ever possible to get two of these parts to point in the same direction at the same time.

The large overlay keeps you prominent while your shared screen is framed next to you — even when using Center Stage. Your room appears in the background (virtual backgrounds are disabled), and you can walk, talk, and move in front of the screen.

Chemically bonding glucose and fructose produces sucrose — the stuff that most people today would call sugar (or maybe table sugar). Its name comes from the French word for sugar, sucre. The disaccharide sucrose is dextrorotatory but a mixture of the monosaccharides glucose and fructose is levorotatory. "Invert sugar" is made by heating a solution of sucrose and water. The two halves of the disaccharide separate (hydrolyze) and the rotation caused by the fructose dominates. The polarization of the solution has been "inverted" but the sugars themselves have not had their chirality inverted. Doing this would require the inversion of the molecule in three separate places, which is an extremely tricky thing to do.

In macOS Sonoma or later, choose Studio Light from the Video menu in the menu bar. To adjust the intensity of this effect, click the arrow next to Studio Light, then use the slider.

Requires macOS Sonoma or later on a Mac with Apple silicon, or macOS Sonoma or later on a Mac using Continuity Camera with iPhone 12 or later

Imagine a light wave traveling toward you, on its way to entering your eye. In what direction is the electric field vibrating? (Light is both electric and magnetic, but it is usually the electric field that we are interested in.) Up and down? Sure. Left and right? Sure, why not. Both alignments are perpendicular to the propagation of the wave.

Light is a transverse electromagnetic wave that can be seen by a typical human. Wherever light goes, the electric and magnetic fields are disturbed perpendicular to the direction of propagation. This propagating disturbance is what makes light a wave. The fact that the electric and magnetic fields are disturbed makes light an electromagnetic wave. The fact that it disturbs these fields at right angles to the direction of propagation makes light a transverse wave. In this section we will explore what it means to be transverse.

The small overlay shows your face in a movable bubble, which gives more space to the screen you're sharing. You can point to important details.

macOS includes a variety of video and audio features that you can use in FaceTime and many other videoconferencing apps.

Requires macOS Sequoia or later on a Mac with Apple silicon, or macOS Sequoia or later on a Mac using Continuity Camera with iOS 18 or later on an iPhone 12 or later

To turn this feature on or off, choose Reactions in the Video menu, which appears in the menu bar when a video call is in progress. To show a reaction without using a hand gesture, click the arrow next to Reactions in the menu, then click a reaction button in the submenu.

Requires a Mac laptop with Apple silicon using the built-in camera, or a Mac using Continuity Camera with iPhone XR or later

Requires macOS Sonoma or later and any of these devices: a Mac using the built-in camera of an Apple Studio Display, a MacBook Pro introduced in 2024 or later using its built-in camera, an iMac introduced in 2024 or later using its built-in camera, or a Mac using Continuity Camera with iPhone XR or later

All sugars produced by living things are right-handed molecules, but they may rotate the polarization of light in either direction. Glucose is the most abundant simple sugar (monosaccharide) and is the primary source of energy for all living things. Its name comes from the Greek word for sweet, γλυκος (glykos). Because it rotates plane polarized light clockwise it is also known as dextrose. Fructose is another simple sugar. Its name comes from the Latin word for fruit, fructus. Because it rotates plane polarized light counterclockwise it is also known as levulose.

Determining whether a particular compound is right- or left-handed is determined by a particularly complicated set of rules that I don't understand (and don't care to understand at this moment), but being able to do so is especially important in organic chemistry. Something possibly useful to know for physics students is that all naturally occurring sugars are right-handed and all naturally occurring amino acids are left-handed (except glycine, which is not chiral).

In macOS Sonoma or later, click Mic Mode from the Video menu or Audio menu in the menu bar, then choose a mic mode. In macOS Ventura or macOS Monterey, click Control Center in the menu bar, then click Mic Mode. Choose from the following mic modes:

spectroscopy, polarimetry, defectoscopy, astronomy, platography, material research, laser applications, light modulation, agricultural production, electric power generation, environmental control devices, molecular biology, biotechnology