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Digging into Nikon RAW Size S NEFs

RawDigger. sNEF

With D4s camera Nikon introduced the new file format they refer to as RAW Size S NEF:

  • It contains not RGB but YCbCr data much like a JPEG;
  • The data is 11-bit;
  • The tone curve is applied to the data;
  • The in-camera white balance is applied to the data;
  • The pixel count is 4 times less than with regular NEF files;
  • The color information is shared between two adjacent pixels (in other words, chroma is recorded for each other pixel);
  • The file size is insignificantly smaller than full resolution 12-bit lossy compressed NEF;

RawDigger 1.0.7

Changes

  • For DNG files having CFA pattern dimensons different from the dimensions in BlackLevelRepeatDim tag black level is displayed correctly:
    • on the BlackLevel button
    • in the black level fields in Prefernces, given Reset Black Level on file load is enabled
  • When the black level is set manually Black Level button at the lower left corner of the main window indicates the number of black level values according to the number of channels (it was always 4 numbers previously)

RawDigger 1.0.6

Changes

  • Support for Nikon Small Raw (D4s NEF Size S):
    • To extract unprocessed YCC data, switch on
      Show YCbCr data for Canon/Nikon sRAW files in Preferences - Data Processing.
    • To disable Cb/Cr interpolation, switch on "Do not interpolate Cb/Cr channels data (Canon/Nikon sRAW)" in Preferences - Data Processing.
    • In RGB-mode ("Show YCbCr…" setting is off) the image is rendered from luma and color-difference data:
      * linearized

RawDigger: detecting posterization in SONY cRAW/ARW2 files

RawDigger. Star Trails

Lossy compression of raw data is currently the only option available in Sony cameras of series NEX, SLT, RX, ILCE, ILCA, and the recent DSLR-A.

The first part of this article is showing how to detect artifacts caused by this compression. We will be discussing the technical details of this compression in the second part of this article.

In the vast majority of cases, the compression artifacts are imperceptible unless the heavy-handed contrast boost is introduced. There are, however, exceptions. With some unlucky starts in alignment, the artifacts can become plainly visible, even without much image processing.

All that is necessary for the artifacts to threaten the quality of the final image is a combination of high local contrast and a flat featureless background.

Lets have a look at the example, which was first published by Lloyd Chambers in his blog.

RawDigger 1.0.5

New Features

  • New Sony processing mode
    Preferences - Data Processing - Sony ARW2 processing options - Delta step relative to value
    This mode is to display the ratio of the minimum delta step to the pixel value. For those image areas where this ratio is large and the contrasty details do not exist (like it is in the sky) the normally processed image may exhibit visible posterization. The values are displayed in per mil (a tenth of percent, or one per thousand).

RawDigger Histograms, part 3: Overexposure Shapes

RawDigger.

Different cameras, even if based on the same sensor, may render extreme highlights at around clipping point differently, and differently, with different values of clipping points, depending on ISO setting. It is important to recognize the look and calculate the practical clipping point, which is not always the same as the maximum raw value.

Here we will try to demonstrate the typical “looks” of the histogram of the clipping zone.

RawDigger histograms: Part 1. What is the raw data histogram?

RawDigger. What is a histogram?

This article is the first of a series, dedicated to explaining what is the histogram of raw data, what are the various ways of exploring it in RawDigger, how it can help to better understand how your camera functions, and how it can aid in improving your shooting through better understanding of raw data. In this one, we are going show you how to navigate the RawDigger histogram.

Before we get to any of this, however, let’s define what exactly IS a histogram of raw data?

Note: If you know what a histogram is, and know the difference between the histogram on the back of the camera and the histogram of the raw data, feel free to skip to the next part. But maybe even if you think you know all about the histograms the below is worth reading.

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