playground:playground
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This is work in progress before it gets inserted into the main doc page. | This is work in progress before it gets inserted into the main doc page. | ||
- | * Exposure helpers: [[#Exposure to the right (ETTR)|ETTR]], | ||
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- | ====== Exposure to the right (ETTR) ====== | ||
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- | Exposure to the right (ETTR) is a technique of setting the exposure of a scene such that few or no pixels are are over exposed (blown out) thus maximizing the information captured without loosing information to over-exposure. | ||
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- | There are two methods (three really) of using ETTR: | ||
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- | The first method involves taking 2 images. | ||
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- | The second method uses the live view momentarily to run through a series of exposures until the exposure is correct without taking a photo. | ||
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- | ETTR sets the shutter speed and ISO. It does not change the aperture setting thus not altering the depth of field of the scene. | ||
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- | In the Expo Tab (Exposure Menu of ML) you will find Auto ETTR: | ||
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- | {{: | ||
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- | Pressing the **Q** button brings you to the settings menu of the ETTR function: | ||
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- | {{: | ||
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- | ==== The Settings ==== | ||
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- | **Trigger mode**: Always ON, Auto Snap, Press SET, HalfS DblClick. | ||
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- | * **Always on** means that every time you take a picture the image is displayed in the LCD monitor with an analysis of the image and the shutter speed and ISO are set for the next shot. | ||
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- | * **Auto snap** means that every time you take a picture the image is displayed in the LCD monitor with an analysis of the image, and that if the results are not adequate it will automatically take another image. | ||
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- | * **Press SET** means that every time press the SET button the current scene is displayed in live view, the image is analyzed by stepping through a series of exposure settings. | ||
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- | * **HalfS DblClick** | ||
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- | For Timelapse set it to **Always on**. | ||
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- | With **Always on** and **Auto snap**, you should definitely enable Zebras and Histogram to see if the settings it choose are correct. | ||
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- | **Slowest shutter**: 1/60 The slowest shutter that will allow for the current scene. . For a night time lapse set it to 30 seconds. | ||
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- | **Highlight Ignore**: 0.2% Percentage of (highlight) pixels to ignore when calculating ETTR. This is used if you want to allow overexposure in the highlights, for example room lights. | ||
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- | **Midtone SNR limit**: 6 Is defined in EV levels of noise in the Midtones form 1 to 8 EV. The higher the SNR the less noise. | ||
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- | **Shadow SNR limit**: 2 Is defined in EV levels of noise form 1 to 4 EV. The higher the SNR the less noise. | ||
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- | ==== The Advanced settings ==== | ||
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- | **Exposure Target**: A general exposure target for the scene, | ||
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- | **Link to Canon shutter**: | ||
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- | **Link to DUAL ISO**: ON or OFF. In ON position the camera will analyze the scene via Trigger mode (4) and decide if DUAL ISO is required or not. Requires the DUAL ISO module to be enabled. | ||
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- | Note: If Link to DUAL ISO is set to OFF, the module will not calculate the required DUAL ISO and the image will only be set to meet the ETTR requirements. | ||
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- | **Show debug info**: ON OFF. Will show some of the important calculation results of this module. | ||
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- | ==== Visual Feedback ==== | ||
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- | If you want more visual feedback as to what's going on, enable histograms and raw zebras: | ||
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- | In the **Overlay Tab** you can scroll down to Histogram and press **Q** to configure: | ||
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- | RAW EV indicator: OFF Here you can press the set button and select ETTR hint. This will display in the RAW histogram a hint of how many more EVs you can expose to meet the ETTR parameters set in previous menu. | ||
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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. | ||
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- | ===== Setting it up ===== | ||
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- | ETTR in RAW images | ||
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- | 1. Go to Canon Menu and set Image Review: hold (This gives you a change to review the RAW histogram until you press half shutter to stop the preview, 2 sec is too quick to analyze the histogram but you can set it as desired NO LESS THAN 2 SEC! | ||
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- | 2. Put the camera in manual M mode or Av mode (either one since you must the aperture yourself), and set ISO to any number except in Auto. It wont work in auto! | ||
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- | 3. Press trash button to enter ML menu. | ||
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- | 4. Go to the Expo Tab and enable Auto ETTR by pressing set. | ||
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- | 5. Press **Q** if you want to change ETTR details. | ||
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- | 6. (optional) enable Global Draw | ||
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- | 6.1 Press **Q** and move to Overlay Tab. Make sure Global Draw in: On, all modes. | ||
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- | 7. (optional) enable Zebras | ||
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- | 7.1 Scroll to Zebras, press **Q**, scroll to the bottom and select Use RAW zebras ON. | ||
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- | 7.2 Press **Q** | ||
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- | 8. (optional) enable the Histogram | ||
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- | 8.1 Scroll to Histogram and press **Q** | ||
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- | 8.2. (optional) Scroll to RAW EV indicator and select ETTR hint by pressing set. | ||
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- | 8.3. Press **Q** | ||
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- | 12. Press trash button to exit ML menu. | ||
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- | ===== Usage ===== | ||
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- | You are highly recommended to use a tri-pod or other support. | ||
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- | ==== Always On mode ==== | ||
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- | 1. Frame you subject and set the aperture (for the DOF) and shoot a test photo. | ||
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- | 2. Now look at the display and you should see the image with the histogram and the zebras in the over exposed areas (if you enabled them). | ||
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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). | ||
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- | ==== Auto snap mode ==== | ||
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- | 1. Frame you subject and set the aperture (for the DOF). | ||
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- | 2. Press the shutter. | ||
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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). | ||
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- | ==== Press Set and HalfS DblClick modes ==== | ||
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- | 1. Frame you subject and set the aperture (for the DOF). | ||
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- | 2. Press the Set button or quickly half-press the shutter release twice depending on the mode. | ||
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- | 3. The camera will go into live view mode and will step through a series of exposures trying to find the proper exposure for the scene and then the camera will go out of live view mode. | ||
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- | 4. Do not recompose your shot. Shoot the scene. | ||
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- | ==== Using the histogram ==== | ||
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- | 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 | ||
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- | 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. | ||
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- | If there are overexposed areas you will see RAW Zebras in the color which is overblown. | ||
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- | Take another picture without changing the scene and you will see how the camera settings are adjusted to meet the ETTR requirements. | ||
- | If the camera beeps it means that the photo is out of specs and you should shoot again. | ||
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- | ===== Convergence to results ===== | ||
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- | 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. | ||
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- | When the algorithm cannot find an adequate exposure it will beep twice and give you a message in the LCD screen. ETTR: expo limits reached, indicating the ISO and speed limits used. | ||
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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. | ||
- | Note: the image review time in the LCD is set via Canon menu in Image Review. | ||
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- | ===== Raw histogram use ===== | ||
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- | It is best to enable RAW Histograms via Global draw. This will put a little histogram on the LCD during image review. | ||
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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. |
playground/playground.txt · Last modified: 2022/05/13 16:55 by WBOX4