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Why does an image of the panel appear to left side of the actual object when the picture is taken if the lamp in a switched on state?


That is most likely the result of an internal reflection between different elements in your lens. Modern coatings can reduce and/or eliminate a lot of internal reflections, but all bets are off when you have an extremely bright light source in the frame.

  • One way to verify this is to place the light source in different parts of the frame, and watch how the orientation of the ghost image changes (or doesn't).
    – Zeiss Ikon
    Apr 9 '20 at 16:47

Modern camera lenses are an array of multiple lenses. Such designs are necessary to mitigate degrading of the image due to aberrations. We are talking about the fact that all lenses suffer from about 7 major distortions. While these aberrations are minimized, they cannot be eliminated. Each of the several lens elements have polished glass surfaces. About 6% of the light that hits a surface is reflected away. This surface reflection is the source of ghost images and flare. We coat each lens surface with a thin transparent mineral overlay. The thickness of this coat and the density of the coat reduces the tendency of surface reflections to about 2%. The coat helps, but does not eliminate ghost images. Also, the imaging chip in the camera has a cover glass for protection, and it also is coated. Ghost images are plagues we must endure.

  • Note that 2% of light, 1/50, is less than six stops dimmer. In Zone System terms, the Zone X+ light source might be reduced to a Zone IV by a single reflection. If the light source is several stops past Zone X, it might still be above Zone 8 after two, perhaps even three reflections.
    – Zeiss Ikon
    Apr 9 '20 at 17:39
  • @Zeiss Ikon -- The 2% loss is per individual lens element surface. A tip of the hat to Harald Taylor, who in 1892, observed that old lenses of the same design as new lenses, passed more light. His investigation, revealed that crud from air pollution (coal burning industrial London) deposited a fine film on shelved lenses. To day we bloom (artificially age) lenses to mitigate surface reflections. Apr 9 '20 at 20:44