RawDigger Brief User Manual

Submitted by lexa on

Program Objective

RawDigger by LibRaw, LLC, is a tool to visualize and examine pure raw data as the camera has recorded it. In essence, it is a microscope of sorts that lets you drill down into raw data.

RawDigger doesn’t alter the raw data in any way. RawDigger is not a raw convertor. Instead, it allows you to see the data that will be used by raw convertors.

RawDigger supports nearly all cameras that have raw capability. Support for new cameras is usually implemented within few weeks after raw samples become available.

Some unique RawDigger features:

  • RawDigger displays the real histogram of the raw data, which greatly differs from the in-camera histogram and histograms presented by most of the raw convertors.
  • Overexposure (OE) indicator will show you exactly what areas of the shot are blown out and in which color channel(s) it happened (best if used in channel view).
  • RawDigger allows determining how exposure meter is calibrated and what raw level corresponds to the midpoint of in-camera histogram. That is, RawDigger lets you establish the headroom in highlights and obtain optimal exposures.
  • For ETTR practitioners, RawDigger makes it very simple to compare raw histogram to in-camera histogram and account for the difference, making the exposures as much “to the right” as possible.
  • RawDigger helps determining the raw level at which the overexposure “blinkies” start on the camera LCD and to know how much headroom is still available after the blinkies start showing.
  • If the shadows look blotchy, colorless, or details in shadows are poorly resolved you will be able to determine how much they are underexposed and set Underexposure (UE) indicator in RawDigger accordingly.
  • RawDigger is a useful tool for examining how the relative per-channel underexposure depends on the color of light.
  • RawDigger is more precise than any exposure meter for the purpose of evaluation of the uniformity of fill light and reproduction light setups (in terms of the evenness of both color balance and luminosity across the background).
  • For studio photography RawDigger helps establishing the proper light filtration to achieve the cleanest possible shadows on the shots.
  • Landscape photographers may want to use RawDigger to determine the effect of the filters on the lens, to check neutrality of polarizing and neutral density filters and, possibly, to select color correction and color compensation filters to use in different light.
  • RawDigger can be used to check the amount of vignetting caused by the lens and the sensor.
  • RawDigger helps determine the idiosyncrasies of both camera and raw convertor by providing a true view into the raw data and comparing it to the results obtained through raw conversion.

Some of the more advanced features, depending on the RawDigger edition, include:

  • RAW data export as TIFF.
  • Plot and save per channel raw data histograms for both the entire file and for an arbitrary rectangular area of the file (selection). The histograms can be saved as graphics or as a table for further external processing.
  • Calculate the statistics per channel (minimum, maximum, average, root-mean-square deviation) for the entire file and for an arbitrary rectangular selection.
  • Calculate the statistics per channel and save the results in a processing-friendly form  - CSV, CGATS (for an arbitrary number of rectangular areas of the file).
  • Save the compression curves of raw files in a tabulated form (for cameras and raw data formats where such curves are used).

RawDigger is available in several editions:

  • Exposure Edition is for everyday use and is intended to help those who are serious about extracting the maximum quality from the camera to get precise exposures.
    Exposure Edition displays RAW data in all modes (RGB, RAW Composite, and RAW per channel), indicates over- and underexposed areas, displays RAW histogram, image statistics, as well as statistics and histogram for selected area.
  • Research Edition is meant for camera/sensor evaluation and statistical analysis of raw data. It is suitable for a wide range of tasks, starting from personal use and preparing reviews and all the way to programming RAW data processing.
    Research Edition adds TIFF export, multiple selected areas via samples, tables of sampled data; statistics and histograms over multiple samples, exporting sampled data as CSV and CGATS.