Electronic viewfinder

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Principle of an electronic viewfinder: The image of a small screen in the electronic viewfinder is virtually reproduced and enlarged with the help of a system of converging lenses in an eyepiece according to Kellner , so that the viewer (right) can see it at a clear visual range .
Digital camera with monochrome live view representation of a colored scene in an electronic viewfinder

An electronic viewfinder (English: electronic view finder (EVF)) is a detector with a very small screen , the virtual image via an optical system is viewed with one eye.

For this purpose, liquid crystal screens or OLED screens, which are operated in live view mode, are used in digital and video cameras . Before this technology was available, small CRT screens were built into television cameras , for example . The photographer or cameraman looks at the electronically recorded image through the lens in the electronic viewfinder and can thus see the exact image section and other information. To adapt the viewfinder to the visual acuity of the user, a diopter compensation can often be carried out by changing the lens position in the viewfinder .

Advantages and disadvantages

Advantages over an optical viewfinder

  • The viewfinder shows the image taking into account the settings for exposure , white balance , color saturation and other effects.
  • An electronic viewfinder can also be used to display images after taking a picture. The photographer can use the viewfinder to check the image immediately after taking the picture without having to remove the camera. This is particularly useful in bright surroundings, since less stray light reduces the contrast in the image when looking into a viewfinder than when looking at a (rear) screen .
  • An electronic viewfinder shows the image regardless of the selected aspect ratio or the set digital zoom, always with complete image field coverage.
  • An electronic viewfinder can display viewfinder images with the imaging errors ( distortion , chromatic aberration , vignetting ) compensated by the camera electronics while recording .
  • In cameras with image stabilized image sensors , an electronic viewfinder shows a calmer image.
  • In a dark environment or when checking the images with a small aperture ( stopping down ), the image can be displayed brighter and therefore more recognizable.
  • The viewfinder can also be used in video mode or with (noiseless) electronic shutter .
  • No parallax .
  • Additional information can be displayed to a much larger and more flexible extent, such as a histogram with the exposure values ​​or highlighting of overexposed image areas, focus peaking , a software magnifying glass , face recognition (possibly also with eye recognition ), the tracking of a focus point set on a subject , an electronic spirit level or auxiliary or grid lines for aligning the camera to the edges of objects or for panoramic photography . In some cameras with a touch-sensitive screen, this can be used while the electronic viewfinder is being used to control the information displayed in the viewfinder image, for example when selecting a menu item or the autofocus area and determining the position of the histogram.
  • Viewfinder images with additional ...

  • ... marking of the recognized and focused faces

  • ... highlighted red highlighting of all sharp edges (focus peaking)

  • ... display of grid and grid lines for aligning object edges

  • ... display of auxiliary lines for vertical alignment of the camera ( rolling and nodding )

  • ... the overexposed areas of the image are marked with a zebra pattern

Disadvantages compared to an optical viewfinder

  • Electronic seekers require electrical energy.
  • Depending on the internal delay time in signal processing, panning cameras or moving subjects may lead to noticeable delays in the display of the displayed image. This delay depends on the speed of the image acquisition, the image processing procedures and the display. However, OLED viewfinders now offer frame rates of up to 240 frames per second.

Web links

Individual evidence

  1. ↑ a b Sony Releases 0.5-type OLED Microdisplay with Top-of-Class UXGA Resolution, Featuring the World's Smallest Pixel Pitch of 6.3µm , Sony press release of May 28, 2018, accessed July 18, 2018.
  2. ↑ a b c Stiftung Warentest : Power lies in the viewfinder. In: test . 3/2014, pp. 38-44.
  3. ↑ Markus Bautsch: Bildaufnahme - Hellheiten , in: Wikibook digital imaging methods , accessed on June 23, 2014.
  4. ↑ Seeker concept , Lumix G Experience, accessed on July 18, 2018.