Differences

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--- doc:appunti:hardware:canon_s120 [2019/03/18 17:51] – [i-Contrast] niccolo
+++ doc:appunti:hardware:canon_s120 [2020/10/31 07:33] (current) – [Exif Tags] niccolo
@@ Line 18: / Line 18: @@
 ^ Exif.CanonCs.AFPoint  | Auto-Focus frame setting. Exiv2 library is incomplete or misleading, here it is the true meaning of values:\\ ''(0)'' => **None** (Manual Focus)\\ ''(16390)'' => **Face AiAF**\\ ''Manual AF point selection'' => **1-point**  |
 ^ Exif.CanonSi.SubjectDistance  | Subject distance, as per manual focus or Auto-Focus. The number seems to be the **distance in cm**, where **infinity** is reported as **6553**.   |
+^ Exif.CanonSi.0x0014  | According to Exiftool source code, this should be **FocusDistanceLower**, where the //SubjectDistance// is actually the **FocusDistanceUpper**. It is supposed that the camera knowns not the actual subject distance, but just two distances where the focus point is in between.  |
 ^ Exif.Canon.0x0027  | This multi-byte tag contains, among others, **Dynamic Range Correction** and **Shadow Correct** settings. Byte 4 (counting from zero) is a bitwise representation, under investigation.\\ Byte 16 is the Dynamic Range Correction:\\ 0 => **Off**\\ 1 => **Auto**\\ 200 => **200%**\\ 400 => **400%**  |
 ^  ISO Speed  ^^
@@ Line 61: / Line 62: @@
 If you choose //Continous// you can see the effect on the LCD display: set the maximum zoom and try to tap slightly and repeatedly on the camera: the image on the screen is more steady than if you set the IS to off.
+==== Dynamic IS ====
+For **movies recording**, beside lens stabilization, it is possible to enable also the **image stabilization via software**. The video actually records a **smaller portion of the screen**: the exceeding part which is cut-off, is used when required to compensate for camera shaking.
+You can enable or disable the software image stabilization for videos from **IS Settings** menu, **Dynamic IS**:
+  * **Option 1**: enable software stabilization, labeled as "//Enhanced stabilization//".
+  * **Option 2**: disable software stabilization (use only lens stabilization), labeled as "//Reduces camera shake//".
+The resulting video - when software IS is active - is **scaled** (**enlarged**) by the camera software, so that **the resulting size is the same** as per video without software IS. This means, for example, that  a Full HD video will be 1920x1080 pixel regardless of the software IS setting, but our test revealed that **the actual area of the video is reduced by 12%** in both width and height.
+===== Manual Focus =====
+  * Manual Focus (**MF**) is available in **P**, **Tv**, **Av** and **M** modes.
+  * Press **[Left/MF]** on the //control dial// and choose **[MF]**.
+  * Press **[Up]** or **[Down]** on the //control dial// (or rotate it) to adjust the focus.
+  * Press **[Right]** on the //control dial// to change zoom magnification.
+  * If **Peaking** option is **On**, edges in focus area are colored in red. See [MENU], camera tab, **MF Peaking Settings...**.
+  * Press **[MENU]** if you want to enable **Focus-BKT**: in that case three images will be shoot, with slightly different focus settings.
+  * Press **[FUNC./SET]** button to accept the focus.
+  * If the **Safety MF** option is **On** (see the [MENU], camera tab):
+    * Move the **focusing frame** (orange rectangle) tapping the touch screen.
+    * Press **halfway the shutter button** to **refine the focus**. Warning! The instruction manual talks about //fine-tune//, but it is not clear how much can be this fine tuning. Some users reported that a manual set of one meter, was corrected by fine-tune to infinite, beacuse no objects to be focused were in the one meter range.
+===== Safety Shift =====
+**Safety Shift** is an option that interferes with manual settings in **Tv** and **Av** modes.
+Pressing the **shutter button halfway** will show the aperture value or the shutter speed **selected automatically to obtain a standard exposure**, if such exposure cannot be obtained, the value is displayed in **orange color**. But if **Safety Shift** is enabled, the manually selected value (aperture or speed) will be corrected and displayed on the screen. To enable this option, press the **%%[MENU]%%** button and search the **%%[Safety Shift]%%** into the //camera tab//.
+===== Neutral Density Filter =====
+In photography, a **neutral-density filter** is a filter that **reduces the intensity of all colors of light** equally. The purpose of a neutral-density filter is to **reduce the amount of light** entering the lens, **allowing combinations** of aperture and exposure time that would otherwise produce overexposed pictures.
+For example you can use it to allow an **high aperture value** and get a **lower depth of field**.
+====== Python Script Download ======
+Here it is a Python script to decode Exif metadata from photos taken by the Canon PowerShow S120: **{{.:canon_s120:canon-metadata.txt|canon-metadata}}**.
+====== Web References ======
+  * **[[https://www.exiv2.org/tags-canon.html|Exiv2 - Canon MakerNote Tags]]**
+  * **[[https://www.dpreview.com/forums/post/35260903|Wow.... focus distance reported in EXIF???]]**
+  * **[[https://photo.stackexchange.com/questions/105977/what-is-focus-distance-lower-upper-and-how-is-it-different-from-depth-of-field|What is “focus distance lower/upper” and how is it different from depth of field?]]**
+  * **[[https://www.dpreview.com/forums/post/51962463|Distance in EXIF]]**