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playground:exposure_to_the_right_ettr [2014/01/25 12:17] – mgrantplayground:exposure_to_the_right_ettr [2014/01/25 12:23] (current) – mgrant
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 Also in the **Overlay Tab** you can scroll to **Zebras**, press **Q**, and make sure that **RAW zebras** are ON.   The **RAW zebras** will show on the image itself to mark the areas where a color channel may be overblown. Also in the **Overlay Tab** you can scroll to **Zebras**, press **Q**, and make sure that **RAW zebras** are ON.   The **RAW zebras** will show on the image itself to mark the areas where a color channel may be overblown.
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-{{:playground:aettr4.jpg|}} 
  
 ====== Step by step intructions ====== ====== Step by step intructions ======
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 12. Press trash button to exit ML menu. 12. Press trash button to exit ML menu.
  
-===== Usage =====+====== Usage ======
  
 You are highly recommended to use a tri-pod or other support.  Multiple images or measurments of the scene will be taken and you do not want to change the scene much between measurements.  Also the shutter speed chosen may be quite low. You are highly recommended to use a tri-pod or other support.  Multiple images or measurments of the scene will be taken and you do not want to change the scene much between measurements.  Also the shutter speed chosen may be quite low.
  
-==== Always On mode ====+===== Always On mode =====
  
 1. Frame you subject and set the aperture (for the DOF) and shoot a test photo. 1. Frame you subject and set the aperture (for the DOF) and shoot a test photo.
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 3. Shoot another a photo and repeat to step 2 until your photo is not over exposed (few or no zebra lines, and the exposure curve up to the right side of the graph). 3. Shoot another a photo and repeat to step 2 until your photo is not over exposed (few or no zebra lines, and the exposure curve up to the right side of the graph).
  
-==== Auto snap mode ====+===== Auto snap mode =====
  
 1. Frame you subject and set the aperture (for the DOF). 1. Frame you subject and set the aperture (for the DOF).
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 3. Now look at the display and you should see the second image with the histogram and the zebras in the over exposed areas (if you enabled them).  If your photo is over exposed, press the shutter again.  The camera will take at least one (and maybe a second photo) again.  Repeat until there are few or no zebra lines and the exposure curve is up to the right of the graph. 3. Now look at the display and you should see the second image with the histogram and the zebras in the over exposed areas (if you enabled them).  If your photo is over exposed, press the shutter again.  The camera will take at least one (and maybe a second photo) again.  Repeat until there are few or no zebra lines and the exposure curve is up to the right of the graph.
  
-==== Press Set and HalfS DblClick modes ====+===== Press Set and HalfS DblClick modes =====
  
 1. Frame you subject and set the aperture (for the DOF). 1. Frame you subject and set the aperture (for the DOF).
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 4. Do not recompose your shot.  Shoot the scene. 4. Do not recompose your shot.  Shoot the scene.
  
-==== Using the histogram ====+===== Using the histogram =====
  
 Inside this histogram you may see near the top-left of the graph, in white lettering, the letter E followed by a number which represents how far you can go, in EV numbers, to reach ETTR, i.e E1.2 Inside this histogram you may see near the top-left of the graph, in white lettering, the letter E followed by a number which represents how far you can go, in EV numbers, to reach ETTR, i.e E1.2
  
 Inside the RAW histogram near the bottom you may see colored circles with numbers inside which represent the overblown channels (R, G, B) and the number of EV of over-exposure.  To see this aim to an area with higher more light and take a pic. Inside the RAW histogram near the bottom you may see colored circles with numbers inside which represent the overblown channels (R, G, B) and the number of EV of over-exposure.  To see this aim to an area with higher more light and take a pic.
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 +{{:playground:aettr4.jpg|}}
  
 If there are overexposed areas you will see RAW Zebras in the color which is overblown. If there are overexposed areas you will see RAW Zebras in the color which is overblown.
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 If the camera beeps it means that the photo is out of specs and you should shoot again.  In the tests I ran I found that in extreme situations the adjustment was completed in three photos.  For most situations the adjustment is done in one shot. If the camera beeps it means that the photo is out of specs and you should shoot again.  In the tests I ran I found that in extreme situations the adjustment was completed in three photos.  For most situations the adjustment is done in one shot.
  
-===== Convergence to results =====+====== Convergence to results ======
  
 With the **Always on** and **Auto snap** setting which takes images, it may require at least two images (sometimes three or four) to come up with the proper exposure.  Alternatively you can set the Trigger mode to **Press Set** or **HalfS DblClick** in which case the camera will go to live view, analyze the scene, and return to photo mode with the correct settings. With the **Always on** and **Auto snap** setting which takes images, it may require at least two images (sometimes three or four) to come up with the proper exposure.  Alternatively you can set the Trigger mode to **Press Set** or **HalfS DblClick** in which case the camera will go to live view, analyze the scene, and return to photo mode with the correct settings.
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 When the algorithm finds an adequate exposure it will beep once and give you a message in the LCD screen. ETTR settled at ISO xxx and the shutter speed.  When the algorithm finds an adequate exposure it will beep once and give you a message in the LCD screen. ETTR settled at ISO xxx and the shutter speed. 
 Note: the image review time in the LCD is set via Canon menu in Image Review.  You may want to set it to atleast 8 seconds so you can see the results in the LCD before it turns off. Note: the image review time in the LCD is set via Canon menu in Image Review.  You may want to set it to atleast 8 seconds so you can see the results in the LCD before it turns off.
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-===== Raw histogram use ===== 
- 
-It is best to enable RAW Histograms via Global draw.  This will put a little histogram on the LCD during image review.  This histogram can show an ETTR hint (how many EVs are required to reach ETTR), or the Dyanmic Range of the image.  It will also show the clipped channels via colored numbered circles. 
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-If you also enabled RAW zebras via Global draw, you will also see, if any, areas of the image are over-exposed.  Black will be completely overexposed, then you can see red, green, and blue channels clipped areas shown with their respective colors.  White will be dark areas completely under-exposed.  
  
 ===== References ===== ===== References =====
playground/exposure_to_the_right_ettr.1390648675.txt.gz · Last modified: 2014/01/25 12:17 by mgrant