2.1. Angle / Speed.

1.1.1. Focal-Plane Shutter.

1.1.2. Leaf.

1.1.3. Rotary.

1.2.1. Rolling.

1.2.2. Global.

1.1. Mechanical:

Physical curtains or blades that travel across in front of the film plane / sensor, blocking the incoming light. These can be of the following types:

1.1.1. Focal-Plane Shutters:

Whether they are horizontal or vertical curtains, typically in newer models is vertical as on standard sensor sizes there is less distance to cover in that dimension (24mm in vertical vs 36mm in horizontal).

1.1.2. Leaf:

Overlapping metal blades that open from the center like an iris. It allows for a more even illumination of the sensor because light from the central area of the lens reaches the entire sensor simultaneously. This characteristic avoids the sequential exposure pattern that is inherent in focal-plane shutters.

1.1.3. Rotary:

A spinning disc with an opening that briefly exposes the film/sensor. The shutter speed with a rotary disc is often defined by the shutter angle, which represents the size of the open sector as a portion of the full 360-degree rotation (this angle directly correlates to the amount of motion blur that is captured in each individual frame of the film).

1.2. Electronic:

The incoming light onto the sensor is controlled by electronically activating / deactivating it.

1.2.1. Rolling:

The exposure process occurs sequentially, typically row by row, starting at one edge of the sensor (often the top) and proceeding to the opposite edge (often the bottom). This means that although every line of pixels receives the correct amount of exposure time, the precise moment at which the exposure begins and ends varies across the area of the sensor. If a scene is changing rapidly or the subject is in motion, it will be captured at slightly different points in time. This temporal difference in the capture process is the fundamental cause of various visual artifacts that are characteristic of rolling shutters.

Due to its relative simplicity and lower manufacturing cost, the rolling shutter mechanism is the more prevalent type found in most consumer-grade digital cameras, including DSLRs, mirrorless cameras, and even smartphones.

1.2.2. Global:

The entire sensor is activated/deactivated simultaneously. This simultaneous exposure ensures that the entire image is captured at precisely the same moment in time, effectively eliminating the spatial distortions that can arise with rolling shutters when capturing moving subjects.

However, due to the more complex sensor design required to achieve simultaneous exposure and readout, global shutters are less commonly found in consumer-level cameras and are typically reserved for more specialized applications, such as high-speed video recording or industrial vision systems.

1.3. Hybrid:

A combination of both electronic and mechanical elements that aims to leverage the benefits of both types, such as for example the electronic front curtain shutter (EFCS). In this mode, the exposure is initiated electronically (typically rolling) by activating the sensor (hence reducing the sound, initial shutter vibration and lag) and terminated mechanically by the closing of the camera's rear shutter curtain.

When it comes to capturing video, the list of suitable shutters drastically narrows down. Whether capturing it on film or digitally, video inherently requires a shutter mechanism that can operate continuously while at the same time rapidly expose each frame. When it comes to film, rotary shutters are the only viable, while in digital, it can be either a global or rolling shutter.

2.1. Angle / Speed:

Shutter angle originated from film cameras and refers to the size of the opening in the rotary shutter measured in degrees, term that has been also lately incorporated into digital cameras, as it provides an easier method to calculate motion blur. Shutter speed represents its equivalent in some digital cameras and describes the time that the sensor is exposed to light, measured in fractions of a second (or seconds for longer exposures), e.g. 1/60.

While still photography finds the shutter speed methodology more adequate (due to its short burst nature), and many consumer level video camaras just offer the shutter speed methodology, professional filmmaking often use shutter angle as the standard measure. A larger shutter angle corresponds to a longer duration that the shutter is open during the exposure of each frame, and thus results in more motion blur. For example, a shutter angle of 180 degrees means that the shutter is open for exactly half of the time it takes to expose one frame (half of the rotary circle is letting light through while the other half is blocking it). This amount is generally conceived to produce motion that appears most natural to the human eye. A shutter angle of 45° is often employed to capture greater details in the expense of less motion blur, while a 360° shutter offers more motion blur and a dreamlike experience.

The translation of shutter angle to shutter speed is based on the frame rate. Frame rate (or frames per second, FPS) is the amount of individual still images that are capture in sequence in a second, to create the illusion of motion (e.g. a frame rate of 24 comprises twenty four images recorded in one second). Lower frame rates record less images and hence there is a larger time gap in between them, resulting in a more "choppy", while higher frame rates capture more images per second and a smoother perception of motion. It is believed that the human eye naturally detect visual changes at rates between 30 to 60, while traditional cinema often employs 24. However, the amount of images per second is not related to motion blur. If the frame rate is low but the shutter angle short / shutter speed fast, the few images will still be recorded in crisp detail.

The formula for the conversion is shutter speed = 1 / (frame rate × (shutter angle / 360)). In easier terms, a shutter angle of 180° translates into a shutter speed of 1 second divided by twice the frame rate, e.g. 1/48, because 180° represents a half circle in the rotary shutter or in other words a half exposure of the frame (360°/2 = 180°), hence its shutter speed equivalent is half the frame rate (24/2 = 48, 1/48).

Shutter angle provides a more intuitive way for filmmakers to consistently control the amount of motion blur in their footage, especially when the frame rate of the camera is varied. Unlike setting a fixed shutter speed, maintaining a constant shutter angle will automatically adjust the exposure time proportionally to changes in the frame rate. This ensures that the appearance of motion blur remains relatively consistent across different frame rates, as the exposure time is always a fixed fraction of the frame duration.

3.1. Motion Blur:

Refers to the streaking or smearing effect that occurs due to the element's movement relative to the camera's film plane / sensor while the shutter is open. In other words, it is recorded as a streak due to it leaving a print of its own movement in the image, the blend of successive points along its path during the exposure time.

It can be either because the element itself is moving, or the camera is moving, or both (although, if both would move in the same direction and speed, motion blur would be neutralised). The extent of this blur is determined by how fast this relative movement is combined with how long the shutter remains open.

An interesting effect can be perceived during motion blur: if the elements receives a very short burst of high intensity light (flash, muzzle-flash, etc), this extremely short exposure compared to the shutter time and high intensity of the light compared to the surroundings will effectively "freeze" the element in time, removing the discernible visual motion blur.

3.2. Temporal Aliasing:

A phenomenon that occurs in video due to the sampling of a continuous motion or signal at discrete time intervals. If the frame rate (the number of still images captured per second) is not sufficiently high to capture the speed of a moving object, the motion can appear to be jerky, discontinuous, or even moving in the wrong direction. The classic example of temporal aliasing is the wagon-wheel effect, where the spokes of a rotating wheel in a video can appear to be spinning much slower than they actually are, or even to be rotating backward. This illusion happens because the camera is capturing discrete frames of the wheel's rotation. If the wheel rotates by a certain amount between each frame, and this amount aligns with the spacing of the spokes, the eye can be tricked into perceiving a different rate or direction of rotation. The Nyquist-Shannon sampling theorem states that to accurately reconstruct a signal, the sampling rate must be at least twice the highest frequency present in the signal. If the frequency of the motion exceeds half the frame rate (the Nyquist frequency), temporal aliasing will occur.

The shutter angle/speed can influence the appearance of temporal aliasing. Longer exposure times can increase motion blur, which might help to smooth out the perceived motion and mask some of the jerky effects of aliasing.

3.3. Banding:

A visual artifact that manifests as unevenly exposed bands in the image (and sometimes sharp transitions between exposed and unexposed portions), that occurs if there is a short burst of light (e.g. flash, muzzle-flash, etc.) relative to a slower sequential shutter mechanism (sequential as the focal-plane shutter or the electronic rolling shutter), hence some parts of it might stay closed / off during the light increment and therefore the image not exposed evenly across.

This effect is also noticeable with screens because their refresh rate interacts with both the camera's frame rate and its shutter speed/angle, and when these three elements are not properly synchronized, banding appears. The frame rate determines how often the camera records the screen, the shutter speed determines how long each sample lasts, and the screen's refresh rate determines when different portions of the screen update. The relationship between all three timing elements determines the specific pattern and movement of the bands visible in the footage.

3.4. Flicker:

Refers to sudden cyclical changes of light across the image. This is due to the refresh rate or frequency of a light source not synchronized with the camera's frame rate and shutter speed/angle. The mismatch between these timing elements causes successive frames to capture the light source at different points in its intensity cycle, resulting in visible brightness variations from frame to frame. Slower frame rates relative to light frequency typically produce more noticeable flickering.

3.5. Artefacts:

Sensor readout noise, compression and digital stabilization algorithms that constantly make micro-adjustments to the frames might sometimes introduce micro jitter (visible when magnified). Whereas in film, it can come from subtle vibrations in mechanism itself or the classic film gate weave (the physical movement of film through the camera).