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RawDigger 0.9.10

Submitted by lexa on

Changes in short (see details)

  • Integrated ExifTool utility for detailed EXIF/Makernotes display.
  • Improved handling of very big Raw files.
  • "Sony ARW2 Hack" for more detailed Sony files inspection.
  • Improved Histogram display.
  • Samples and Selections are movable by mouse.
  • Many minor interface changes.
  • Several minor bugs eliminated.

Beware the Histogram

Submitted by lexa on

Rawdigger. Raw Histogram

The histogram for an image and the overexposure warning are meant (in theory) for objective verification of the image while shooting and adjustment of shooting parameters according to the indications in the preview window one can see the overexposed areas right away, and the histogram displays the overall distribution of tones on the shot.

The goal of this article is to elaborate on the procedure of juxtaposing the camera histogram and the real raw data, as opposed to merely provide settings and numbers. This, among other reasons, was why the shooting conditions were not exactly typical.

We used a 5D Mark II camera with a 2.0.9 firmware and at 200 ISO. For other cameras, different shooting conditions, possibly other ISOs, and other firmware, separate measurements are to be performed.

RawDigger 0.9.9

Submitted by lexa on

Changes

  • Added an option to set selection in pixel coordinates (Menu-Selection-Set Selection by Numbers)
  • Changed the behavior of Preferences dialogue to make it more intuitive
  • Reduced the amount of memory used
  • Data Processing settings (Subtract Black and its modes, Linear Curve) now affect the RGB on-screen rendering
  • When "Masked Pixels" parameter is changed:
    • the selection area is re-calculated to preserve the selection position relative to the image (that is, selection coordinates are changed)
    • if "Masked Pixels" is turned off the selection areas that include masked pixels are deleted
  • New Preferences parameter: Use Regional settings when saving CSV/CGATS.
    • If it is switched on, the decimal separator is set in accordance to the system settings; and if decimal separator is set to period (".") in system settings - a semicolon (";") is used for separating fields in CSV/CGATS files
    • If the parameter is switched off, period (".") is used as the decimal separator, and comma (",") is used as the field separator.

Digital camera light meter calibration

Submitted by lexa on

RawDigger. Exposure meter calibration

Unlike film sensitivity, which can be measured using a standard procedure, the sensitivity of a digital camera is somewhat a fuzzy concept.

Moreover, the sensitivity of the camera turns out to be a pretty random variable, and the camera manufacturers do not make it easier for the user, adding quirks of their own.

Further on we will discuss a simple method, which allows us to calibrate the exposure meter in such a way that on different cameras (or on different sensitivity settings of the same camera) the results are predictable.

Determining pixel charge capacity and amplification gains for a digital camera

Submitted by lexa on

Unlike its film-using predecessors, modern digital cameras present us with a challenge of a non-replaceable sensor. Due to this, the given amount of light, which falls on an element of the sensor (pixel), creates the same charge irrespective of ISO sensitivity setting resulting in an identical output signal. The response of the sensor itself depends only on the light, and not on the digital camera sensitivity (ISO) setting.

It would seem that this contradicts everyday photographic practices: if there is not much light, you have to set the sensitivity (ISO value) higher, and the picture will come out right, but if you set the sensitivity low, then it won t come out right. Lets have a closer look.

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