from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A system of three (not five) mirrors used as a cheaper substitute to a pentaprism in the viewfinders of some single-lens reflex cameras


from Wiktionary, Creative Commons Attribution/Share-Alike License

penta- +‎ mirror


  • Sony's Live View mode is also unusual, because it uses a secondary sensor inside the pentamirror that doesn't interfere with the A500's autofocus system, unlike other digital SLR designs.

    Imaging Resource What's New

  • (It seems to me that beneath the pentamirror prism would be an ideal location which wouldn't likely be bumped or covered).

    Imaging Resource News Page

  • • Dedicated live view sensor (pentamirror tilt system) • 1200 zone evaluative metering

    Photography Tips

  • The pentamirror viewfinder is otherwise unchanged from that of the K-x, with the Pentax K-r providing the same 96% viewfinder coverage, 0. 85x magnification, and -2.5 to +1.5 diopter adjustment.

    Imaging Resource News Page

  • You can easily see the gradually increasing size of the cameras - and the size of the pentaprism / pentamirror hump as you move up the range.

    News: Digital Photography Review (

  • In addition to the Live View LCD, the camera also features an eye-level pentamirror single-lens viewfinder covering about 95\% of the frame.

    DailyTech Main News Feed

  • Here you press a button on the left of the camera's pentamirror housing and it pops up.

    Imaging Resource News Page

  • I suspect this is due to how Nikon trimmed its outer dimensions as well as the addition of an actual pentaprism in substitution for the D70's pentamirror arrangement.

    Imaging Resource News Page

  • A normal pentamirror arrangement reflects the light out the optical viewfinder eyepiece..

    Imaging Resource News Page

  • First, it moves the mirror to reflect the light to the secondary sensor inside the pentamirror housing.

    Imaging Resource News Page


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