Electronic shutter

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An electronic shutter with photographic images will also be silent or silent closure named because it requires no mechanical components, and therefore does not cause noise.

No moving components are required for the corresponding recordings because they are controlled completely electronically . The exposure processes include resetting the light-sensitive elements, adhering to a specified exposure time during light exposure and then reading out the sensor signals.

Electronic locks are increasingly being used to supplement or replace mechanical locks in still and moving image cameras, provided that these do not work with photographic film but with electronic image sensors .

With SLR cameras , a shutter-release noise is created when taking a picture, especially when the mirror is folded up and down. With film cameras , it is primarily the transport of the film that generates noise. Most high-quality still and moving image cameras also have a mechanical shutter that covers the image sensor or completely dims the lens and only releases it during the exposure period. Nowadays, a silent shutter is state of the art, especially for video recordings . With the silent shutter for taking still pictures, a camera is operated in video mode without permanently recording image data. The image sensor is permanently reset, exposed and read out, for example to enable viewfinder images in live view .

advantages

  • No noise when taking photos or filming, which can be an advantage, for example, during theater or concert performances or when shooting wild animals.
  • No shaking of the camera and therefore no blurring of the recordings caused by it.
  • No wear on mechanical components.
  • Very short exposure times are possible, especially with smaller image sensors (some cameras from Fujifilm and from the Sony RX series, the Olympus OM-D E-M5 III and M1X or the Panasonic Lumix DC-G9 , for example, can only expose 1 / 32,000 second ). Conventional mechanical shutters cannot expose for that short.
  • Enabling quick series of images or multiple exposures, such as for series photography , for focus stacking or tracking of objects, as well as for pixel shift (several images with slightly shifted image sensor) or high-contrast images .
  • Due to the missing edges of the mechanical shutter, no undesirable effects are caused in the image by diffraction at these edges.

disadvantage

Many digital cameras nowadays do not have CCD sensors for image recording, among other things because of the high image resolutions , but CMOS sensors which, due to the system, can only read the image lines sequentially, i.e. line by line or column by column. Due to the sequential reading of the image lines, geometrical distortions can occur with moving subjects (see also rolling shutter effect ). The image of the moving subject is at different points in time on the image sensor. The faster the image can be read out, the less this effect is.

Some digital SLR cameras have the option of silently triggering the shutter in live view mode, but the optical viewfinder does not show a picture.

When taking pictures with flash, it must be ensured that the flash is available evenly during the entire exposure. Flickering light sources, such as gas discharge lamps , which are not necessarily visible to the human eye, can result in uneven exposures in the image.

The complete resetting of the image sensor without exposure as with a closed mechanical shutter is not possible, so that the uninterrupted exposure can limit the dynamic range of the brightnesses in the recorded images.

Furthermore, without additional acoustic signals, the user cannot hear when and whether the camera is triggered.

With global electronic shutters (“global shutter”), the image sensor can be read out completely and simultaneously, so that some of the disadvantages mentioned above do not arise.

Web links

Individual evidence

  1. Fujifilm presents an extended version of the X-T1 , top-foto.de, September 10, 2014, accessed on February 8, 2020
  2. The Sony A7s is quiet ... very quiet even! , photografix, June 14, 2014, accessed February 8, 2020
  3. What is the "electronic first shutter curtain" function? , Sony , October 8, 2019, accessed February 8, 2020
  4. a b c Richard Butler, Samuel Spencer: Panasonic Lumix DMC-G7 Review , Digital Photography Review, July 6, 2015, accessed February 8, 2020
  5. Bokeh and Electronic Shutter , pen and tell, December 7, 2018, accessed February 8, 2020
  6. Rolling and Global Shutter (CMOS sensors) , Stemmer Imaging, accessed February 8, 2020
  7. Photo tip - The silent lock , test.de , February 26, 2020, accessed on March 1, 2020
  8. Flashing with CMOS industrial cameras and rolling shutter , SVS-Vistec, accessed on February 8, 2020
  9. ^ Rolling Shutter , movie college, accessed February 8, 2020
  10. Sony develops CMOS sensor with global shutter function , photoscala, February 21, 2018, accessed February 8, 2020