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omd:live_histogram

live histogram in Olympus cameras

what is the Live Histogram

  • this is a chart which displays relative frequency of all pixel values in the image
  • the horizontal axis represents the pixel brightness and covers approximately 8 stops of brightness from ~-4EV on the far left to ~+3.7EV on the far right
  • pixels to the right of this will be represented as a red vertical line on the far right and can be expected to be “blown out” in jpegs
  • pixels to the left of this will be represented as a blue vertical line on the far left and can be expected to be “blocked out” in jpegs
  • the light meter aims to make all subjects exposed so they approximate an 18% gray card and thus the pixels will be represented primarily in the centre of the histogram
  • most scenes however are made up of a wide range of brightness values and these will be spread across the histogram
  • if the histogram is mainly to the left of center via exposure compensation or manual exposure, your scene will be dark, and vice versa if it is to the right

activating the live histogram

  • Menu:Cogs:D:Info Settings:LV-Info: Live histogram icon = ON
  • Menu:Cogs:D:Info Settings:Playback Info: histogram = ON allows playback histogram
  • in picture taking mode, pressing INFO button will toggle through all the activated display types including Live Histogram

using the live histogram

  • the metering, including the live histogram is dependent upon jpeg settings and white balance
  • it is an AVERAGE of the 3 colour channels
    • do not use this for colors of only red, green or blue or when using an IR filter as it will be misleading and risk blown highlights UNLESS you have set Picture Mode to Monotone and applied a filter so it is only reading one colour channel - eg. for IR choose the Red filter in the Picture Mode so only the red channel will be metered.
  • the width of the histogram represents ~8EV
  • the green area represents the subject in the centre spot of the scene
    • gives a defacto spot meter even in ESP mode!
    • if aim at white paper (+2.3EV), the green area should be near the right end but there should still be a gap
    • if aim at average Caucasian skin (+1.0EV) the green areas should be just a little to the right of middle of the histogram
    • if aim at black paper or an iPhone screen that is turned off (-3EV), the green area should be near the far left but there should be a gap to the left
omd/live_histogram.txt · Last modified: 2015/09/19 02:50 by gary1