Once the mirror is flipped upwards a small door will move from top to bottom exposing the sensor beneath. After that another door will fall down, covering up the entire sensor. This process can vary in time\u00a0depending on\u00a0the length of your shutter speed. Sometimes a shutter speed can be so fast that your camera sensor won’t be entirely exposed at any one time.<\/p>\n
After the second door closes your mirror will fall back into place. The doors will then reset\u00a0to their original positions underneath. This entire process from mirror up to mirror down is known as an\u00a0actuation. A typical DSLR can\u00a0withstand\u00a0over 100,000 actuations<\/strong> in its lifetime.\u00a0<\/span><\/p>\n The following is a graphic example of 1 full\u00a0actuation:\u00a0<\/span><\/p>\n Unlike DSLRs, mirrorless cameras don’t use a mirror box or pentaprism to project light directly into the viewfinder. Instead, when using a mirrorless camera the sensor is perpetually exposed<\/strong> to incoming light by default with nothing in-between. This is why mirrorless cameras use either an LCD screen or an electronic viewfinder to monitor what is coming through the lens.<\/p>\n As soon as the user hits the shutter button a door will swing up to cover the sensor. Once covered up the sensor will begin exposing. The door will then swing down to expose the sensor to light<\/strong>. After that another door will swing down to cover the sensor. The sensor will then stop exposure and the doors will reset.<\/p>\n Here’s an example of how a mirrorless camera works:<\/p>\n Before the existence of digital sensors it was vital your camera have a mechanical shutter. This is because\u00a0you can’t simply turn film on or off like a digital sensor.\u00a0Pre-developed film is light sensitive, meaning any exposure to outside light would severely damage your images. However, in the age of digital photography\u00a0the landscape is certainly different. Modern sensors are fully capable of taking photographs without a mechanical shutter.<\/p>\n Smaller consumer cameras like point-and-shoots and phone cameras are all examples of shutterless cameras.\u00a0Shutterless cameras tend to have more image noise in the image\u00a0than their traditional shuttered counterparts. This is because shutterless cameras constantly send power to the sensor. When a user hits the shutter button the sensor is flooded with more power and the image is captured and if you’re familiar with\u00a0ISO\u00a0<\/strong>you know that more\u00a0power equals more noise.<\/p>\n We will likely see professional shutterless cameras in the future, but for now they simply are too grainy\/noisy\u00a0for most high-end professional photography.<\/p>\n When shooting video on a the shutter process is much different. Because a typical still\u00a0camera\u00a0can only activate it’s shutter mechanism about 6 times per second, the physical shutter doors are far too slow to shoot video (which is typically shot in 24 or 30 fps). Instead, when shooting video or in the live-view mode your shutter doors and mirror are left open, leaving your sensor perpetually exposed<\/strong>. Instead of relying on mechanical processes, the ‘shutter speed’ when shooting video is only a reference to a timed amount\u00a0of power that goes through the sensor. This is known as an electronic shutter. After each frame is captured the electronic\u00a0shutter resets.<\/p>\n Although the name would insinuate that it is simply a type of shutter process, a global shutter\u00a0is more a camera sensor related feature.\u00a0When it comes to camera sensors there are two main categories that you need to know CMOS and CCD.<\/p>\n CMOS sensors are more common among consumer\u00a0to pro-sumer cameras, but they are also more problematic. This is because CMOS sensors read pixel information from the top left of the sensor to the bottom right. This is a\u00a0problem because if your subject is incredibly fast and moves position during capture you will get warped images. This is known as rolling shutter and it can produce some pretty annoying ‘jello’ effects, especially when shooting video.<\/p>\n On the other hand CCD sensors, or global\u00a0shutters, will record the entire frame at once, very similar to a film camera. This eliminates warping, leaving you with a more\u00a0pleasing image.<\/p>\n Rotary disk shutter\u00a0only pertains to actual film (movie) cameras. As you probably already know, a film camera works by exposing 24 individual film frames to light per second. The result is fluid motion that gives the illusion of movement<\/strong>. As you can imagine, the mechanical processes already covered in this article, known as focal-plane shutters, are far too complex and time consuming to be performed 24 times per second. Instead a film camera uses a rotary disk shutter.<\/p>\n This shutter looks very similar to a\u00a0fan. In short, the Rotary Disk rotate on the inside of the camera body, exposing the film to light\u00a0then covering it up again with\u00a0the blade of the disk. The rotary disk process works in 3 steps: under the cover of the disk the camera film\u00a0would move into place, the disk would allow light in, and the disk would cover the frame. Repeat this process\u00a024 times per second <\/strong>and you have yourself a moving picture.<\/p>\n The thing that makes rotary disk shutters\u00a0truly unique is the way in which the shutter speed is calculated. In modern cameras you can select the exact shutter speed you want for your image, but in traditional film (movie) cameras you have to calculate your shutter speed yourself. Rotary disks have the shutter angle, or the size of the pizza slice (see chart), listed on their blades. DP’s can\u00a0then go in and determine what the shutter speed is\u00a0by calculating the shutter angle with the frame rate.<\/p>\n For example, if you were shooting a film at 24 fps and had a rotary disk\u00a0with a shutter angle of 180 degrees your shutter speed would be 1\/48 or double 24 fps. The following diagram may help you get a good idea of how this process\u00a0works.<\/p>\n If you are looking to shoot on film in the near future there are a lot of really good online resources<\/a>\u00a0to help you figure out your shutter speed. It’s also not uncommon to see shutter speed displayed\u00a0by shutter angle when shooting on high-end cinematography cameras.<\/p>\n A leaf shutter\u00a0is a shutter that functions inside of a lens. Instead of acting like a door or a fan, a leaf shutter works a lot like a lens aperture.<\/p>\n You won’t find leaf shutters\u00a0in everyday cameras. Typically they are only found in medium format high-end photography cameras. They\u00a0can function at higher flash sync speeds (up to 1\/1600) making them great for anyone who wants to shoot outdoors at a low f-stop with a strobe. Because these lenses are hand crafted, not manufactured on an assembly line, they tend to be incredibly expensive.<\/p>\n The following videos showcase various camera shutters in slow motion. Note\u00a0how violent the process is on the photography equipment. It\u2019s amazing that the camera shutters don\u2019t break more often.<\/p>\n![\"Shutter](\"http:\/\/pbblogassets.s3.amazonaws.com\/uploads\/2015\/02\/Shutter-Example.gif\")
<\/a><\/p>\nHow do mirrorless camera shutters work?<\/h2>\n
<\/a><\/p>\nWhy do cameras have mechanical shutters anymore?<\/h2>\n
<\/a>Image from Shutterstock<\/a><\/em>
\n<\/a><\/p>\nHow do shutters work when capturing video?<\/h2>\n
What is a global shutter?<\/h2>\n
\n<\/a>Image from Andor.com<\/a><\/em><\/p>\nWhat is a rotary disk shutter?<\/h2>\n
\n<\/a>Image from Wikipedia<\/a><\/em>
\n<\/a><\/p>\n<\/a><\/p>\nWhat in the heck is a leaf shutter?<\/h2>\n
<\/a>Image from KernPhoto<\/a><\/em><\/p>\nShutters In-Action<\/h2>\n
Nikon D4 (DSLR)<\/h3>\n