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raw_based_exposure_feedback [2021/02/04 06:45]
Audionut more formatting
raw_based_exposure_feedback [2021/02/04 08:32] (current)
Audionut more formatting
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   * [[#RAW vs JPG]]   * [[#RAW vs JPG]]
  
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 {{ https://s1.postimg.cc/32j1k4ilj3/Spot_ETTR.jpg?200}} {{https://s1.postimg.cc/77emw8deq7/Spot_Midtone.jpg?200 }} {{ https://s1.postimg.cc/8l1609lw5r/Spot_Highlight.jpg?200  }} {{ https://s1.postimg.cc/32j1k4ilj3/Spot_ETTR.jpg?200}} {{https://s1.postimg.cc/77emw8deq7/Spot_Midtone.jpg?200 }} {{ https://s1.postimg.cc/8l1609lw5r/Spot_Highlight.jpg?200  }}
  
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 ==== Histogram ==== ==== Histogram ====
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 The colored circles in the histogram, warn of overexposure in the color channel The colored circles in the histogram, warn of overexposure in the color channel
-((This information is derived from the downsized Live View stream.  So the percentages reported, may not be an //extremely// accurate representation of the actual percentage, but provides useful information nonetheless.)).  Small circles show a very small amount of exposure, with the circles increasing in size.  When at least 1 % of the pixels of a channel are overexposed, the numbers inside these colored circles, describe the percentage of pixels that have been overexposed in that color channel.  In the above example. 1% of red pixels have been overexposed, 10% of green pixels and 2% of Blue pixels.+((This information is derived from the downsized Live View stream.  So the percentages reported, may not be an //extremely// accurate representation of the actual percentage, but provides useful information nonetheless.)).  Small circles show a very small amount of exposure, with the circles increasing in size.  When at least 1 % of the pixels of a channel are overexposed, the numbers inside these colored circles, describe the percentage of pixels that have been overexposed in that color channel.  In the above example. 1% of red pixels have been overexposed, 10% of green pixels and 2% of Blue pixels.\\  
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 == Histogram Dynamic Range Feedback == == Histogram Dynamic Range Feedback ==
  
-The histogram in ML also contains [url=http://en.wikipedia.org/wiki/Dynamic_range]Dynamic Range[/url] feedback.  This describes the ratio between the reported white level, and the [url=http://en.wikipedia.org/wiki/Noise_floor]Noise Floor[/url] of the camera, and is only very accurate when the image contains overexposed pixels.+The histogram in ML also contains [[wp>Dynamic_range|Dynamic Range]] feedback.  This describes the ratio between the reported white level, and the [[wp>Noise_floor|Noise Floor]] of the camera, and is only very accurate when the image contains overexposed pixels.
  
-[img width=300]https://s1.postimg.cc/5f8wn5utwv/DR_hint.png[/img]+{{ https://s1.postimg.cc/5f8wn5utwv/DR_hint.png?200}} {{https://s1.postimg.cc/67ls4wdd33/Histo_DR.jpg?200 }}
  
-[img width=400]https://s1.postimg.cc/67ls4wdd33/Histo_DR.jpg[/img]+Note The brown area in the rear of the histogram represents this noise floor. 
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-Note:  The brown area in the histogram represents this noise floor. 
  
-[hr] +===Simplified Histobar ====
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-[anchor=Histobar][color=green][u][size=14pt][b]Simplified Histobar[/b][/size][/u][/color][/anchor]+
  
 +{{ https://s1.postimg.cc/9gxnfpuab3/Histobar.png?200}}
 For LiveView work, there is also the Simplified Histobar. For LiveView work, there is also the Simplified Histobar.
  
-[img width=300]https://s1.postimg.cc/9gxnfpuab3/Histobar.png[/img]+
  
 The Histobar is shown here at the top left of the liveview screen. The Histobar is shown here at the top left of the liveview screen.
- +{{https://s1.postimg.cc/8s4dvpcbwv/Histobar1.png?200 }}
-[img width=400]https://s1.postimg.cc/8s4dvpcbwv/Histobar1.png[/img]+
  
 Red indicates overexposure, blue indicates extreme underexposure, and the yellow bar represents the midpoint. Red indicates overexposure, blue indicates extreme underexposure, and the yellow bar represents the midpoint.
 The blue bar increases in size with increasing underexposure.  So the image above shows a small amount of the scene is extremely underexposed, and a full bar would indicate a large amount of the scene is extremely underexposed. The blue bar increases in size with increasing underexposure.  So the image above shows a small amount of the scene is extremely underexposed, and a full bar would indicate a large amount of the scene is extremely underexposed.
  
-The midtone point is the median of the scene.  For further information, see [url=http://www.magiclantern.fm/forum/index.php?topic=8539.msg80044#msg80044]this post[/url] by a1ex.+The midtone point is the median of the scene.  For further information, see [[ml>forum/index.php?topic=8539.msg80044#msg80044|this post]] by a1ex.
  
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-[anchor=Zebras][color=green][u][size=14pt][b]Zebras[/b][/size][/u][/color][/anchor] 
  
-[img width=300]https://s1.postimg.cc/6ggsz6eh5r/Zebras.png[/img]+==== Zebras ==== 
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 +{{ https://s1.postimg.cc/6ggsz6eh5r/Zebras.png?200}}
  
 Zebras provide a graphical overlay of the areas in the scene which are overexposed, and underexposed. Zebras provide a graphical overlay of the areas in the scene which are overexposed, and underexposed.
  
-[img width=360]https://s1.postimg.cc/1htaknr6en/Zebra1.png[/img] [img]https://s1.postimg.cc/2dd0lxt9zz/97pwi.gif[/img]+{{https://s1.postimg.cc/1htaknr6en/Zebra1.png?200 }} {{https://s1.postimg.cc/2dd0lxt9zz/97pwi.gif?200 }} 
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-And a scene showing zebras/histogram, with overexposure, and underexposure.+{{ https://s1.postimg.cc/96atmkc24v/Histo_Zebras.jpg?200}} 
 +And a scene showing zebras/histogram, with overexposure, and underexposure. -> See image
  
-[img width=400]https://s1.postimg.cc/96atmkc24v/Histo_Zebras.jpg[/img] 
  
 As with the histogram, the color displayed by the zebras, represent the color channel in the camera that is overexposed.  Again, a Cyan reading is describing overexposure in both the Green, and the Blue channels, Yellow describing both Green and Red channels, and Magenta describing both Red and Blue channels. As with the histogram, the color displayed by the zebras, represent the color channel in the camera that is overexposed.  Again, a Cyan reading is describing overexposure in both the Green, and the Blue channels, Yellow describing both Green and Red channels, and Magenta describing both Red and Blue channels.
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-Unlike the histogram, black describes overexposure in all color channels, and white describes underexposure.  [s]This underexposure point describes any data that is within 1 EV of the camera noise floor[/s]. +{{ https://s1.postimg.cc/9b9h4ytg7j/Zebra_under.png?200}} 
- +== Raw Zebra Underexposure== 
- +This allows you to choose at what exposure the [[/glossary/#underexposure]] zebras will be displayed.  0 EV means that the zebras will be displayed where the amount of [[/glossary/#noise]] in the image, is equal to the amount of signal in the image (the [[/glossary/#SNR|noise floor]]).  
-Update:  dmilligan added some underexposure adjustment to the zebras. +
-[img width=400]https://s1.postimg.cc/9b9h4ytg7j/Zebra_under.png[/img] +
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-This allows you to choose at what exposure the underexposure zebras will be displayed.  0 EV means that the zebras will be displayed where the amount of noise in the image, is equal to the amount of signal in the image (the noise floor).  +
 A general consensus amongst photographers, is that the limit for acceptable amount of noise in images, is 2 EV above this noise floor. A general consensus amongst photographers, is that the limit for acceptable amount of noise in images, is 2 EV above this noise floor.
  
raw_based_exposure_feedback.1612417552.txt.gz · Last modified: 2021/02/04 06:45 by Audionut