DPRSplit Beta 0.8: File Splitter for Canon 5D Mark IV / Dual Pixel Raw files

What this application is for:

Canon 5D Mark IV's sensor has a somewhat unusual pixel arrangement: each pixel has a dual photodiode construction. Each photodiode is associated with a subpixel, and thus the pixel is split in two. If Dual Pixel RAW mode is enabled in the camera, the resulting CR2 file contains two images, or two frames: one composite, made from reading both subpixels, summed; and the other is made out of one set of subpixels. In other words, a pixel is composed of two subpixels, let’s call them A and B. The first frame in a CR2 file is made of “A+B”, while the second is made from “B” subpixels only.

Canon Dual Pixel example

The screenshot above shows two frames of one such shot taken in Dual Pixel RAW mode, extracted via DPRSplit, and processed in Adobe Camera Raw 10.1 (with all sliders set to zero), and further opened in Photoshop

Left: the “B” frame – all of the highlights are preserved. Right: the “A+B” frame, the sky and some areas of the mountain are featureless and blown out.

The intended use of this arrangement is to enable some extra editing after the shot: because of the parallax between the subpixels, Canon Digital Photo Professional software allows one to preform microadjustment of focus, bokeh shift, and ghosting reduction.

However, there is one more possible use for a dual-pixel raw, which is not covered by the manufacturer: the second frame, the one that is made out of only “B” pixels, collects half of the light that the composite frame does, as if it was exposed one stop lower compared to the composite frame. In essence, in Dual Pixel Raw mode, the camera records into one file some equivalent of two shots, bracketed by (approximately) 1 EV.

DPRSplit Beta 0.8

The DPRSplit application allows one to:

  • Extract the second (1 EV down) frame or both frames from Dual Pixel RAW CR2 files;
  • And save the extracted frames as DNG files.

Resulting DNG files can then be opened and processed in (practically) any raw converter featuring DNG support.

System Requirements

  • OS and CPU
  • Windows *: Windows 7 – Windows 10, 64-bit
  • Mac OX: Mac OS X/macOS 10.6-10.13, 64-bit processor (so, all Intel Macs, except for some models from 2005-06 with Core Solo and Core Duo processors)
  • Screen resolution no less than 1600x900
  • 50MB of disk space for the application

Download Links

Beta 0.8.3:

  • Better handling of file names provided in non-default character set
  • Automated font size seletection on 1st run

Beta 0.8.2:

  • Adjust EXIF shutter speed by -1EV for second frame (for HDR merge) – simulates reduction of exposure by 1 stop by setting the shutter speed in EXIF 1 stop higher. This may be useful (and even necessary) while merging first and second frame in certain HDR stacking applications that analyze frames for exposure parameters.
  • Preferences - Output DNG Settings - Data Maximum: controls the content of the DNG White Level tag:
    • Normal White –«white» will be set to the Normal White value found in makernotes of CR2 file.
    • Specular White – «white» will be set to the SPecular White value found in makernotes of CR2 file.
    • Data Max (or specular) – «white» will be set to the actual maximum found in raw data of the CR2 file or to Specular White, if Specular White is higher.
    • Data format max – 16383 (minus the black level if the processing mode is set to subtracting black). This option may result in color artifacts in the highlights (such as pink clouds) if the raw converter incorrectly clips the highlights after applying white balance.

Beta 0.8.1: default font size is selected based on screen size on 1st run. If you've changed preferences, stored value will be used (change Base Font Size to get window size smaller).

Getting in touch with us

This is a beta version, and it’s important to us to know your thoughts and suggestions. To contact us, please use:

* We don’t see much need in a Windows/32-bit version of the application, but should there be demand, we will create supply.


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